CN107686560A - A kind of preparation method of the flame-retardant modified composite phenol formaldehyde foam of cellulose - Google Patents

Abstract

A preparation method of cellulose flame-retardant modified composite phenolic foam, using flame retardant 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and itaconic acid for grafting reaction, Preparation of DOPO‑g‑ITA for modified cellulose, and then use DOPO‑g‑ITA flame retardant grafted cellulose, and for the preparation of DOPO‑g‑ITA flame retardant grafted cellulose modified phenolic resin, and finally use Preparation of cellulose composite phenolic foam. The interfacial compatibility between the modified cellulose prepared by the method of the present invention and the phenolic resin matrix is significantly improved, the amount of cellulose added in the composite foam is greatly increased, and the prepared cellulose modified phenolic resin has moderate viscosity and strong expandability , the mechanical properties of the prepared cellulose composite phenolic foam are significantly improved, the pulverization rate is significantly reduced, and the flame retardancy is slightly improved, which reduces the production cost of the composite foam and is conducive to the popularization and application of the phenolic foam composite material.

Description

A preparation method of cellulose flame-retardant modified composite phenolic foam

technical field

The invention belongs to the field of preparation of composite materials, in particular to a method for preparing a flame-retardant modified composite phenolic foam of cellulose.

Background technique

Phenolic foam is a kind of thermosetting foam formed by blending various additives (including surfactants, foaming agents, curing agents, etc.) with phenolic resin and foaming and curing at a certain temperature. Compared with polyurethane and polystyrene foam, phenolic foam has the advantages of good fire resistance, heat resistance, self-extinguishing, resistance to flame penetration, less smoke and no dripping during fire. As thermal insulation materials, phenolic foam is widely used in places with high fire protection requirements such as large public buildings, special ships, aviation equipment, and oil pipelines. However, the defects of high brittleness and high pulverization rate of phenolic foam seriously limit its popularization and application.

In recent years, fires caused by high-rise building insulation materials have occurred frequently, causing a large number of casualties and property losses. As a foam insulation material with self-flame retardant properties, phenolic foam and its composite materials have gradually become a research hotspot, especially the use of natural fibers or cellulose to modify phenolic foam to prepare phenolic foam composite materials. A batch of inventions have been applied for: CN201611106054.1 reports a preparation method of nanocellulose-modified phenolic foam, which prepares modified phenolic foam by introducing nanocellulose into expandable phenolic resin, and utilizes the small size of nanocellulose , high specific surface area, high mechanical strength and other characteristics improve the mechanical properties of the foam, and achieve the effect of toughening the phenolic foam; CN201410584376.1 reports a preparation method of cellulose-modified phenolic foam, which is prepared by partially replacing phenol with cellulose solution Cellulose phenolic resin, and then foaming to prepare cellulose modified phenolic foam, the introduction of cellulose solution can partially replace phenol, which reduces the production cost of phenolic foam and promotes the efficient utilization of biomass resources; CN104004319A reported a The thermal insulation and flame-retardant phenolic foam material reinforced by plant fibers and its preparation method are prepared by mechanically mixing plant fibers with different lengths of hollow structures soaked in flame retardants, phenolic resins and various additives, and then foaming and curing. The plant fiber-reinforced phenolic foam material used for building interior and exterior walls has good thermal insulation and flame-retardant properties, and can reduce the production cost of the phenolic foam material; CN102114659A reports a fiber-reinforced flame-retardant foam composite board and its preparation method, through Fiber-reinforced phenolic foam or melamine-modified urea-formaldehyde foam treated with a coupling agent is used as the core material, and the flat plate is attached to the outer layer of the foam core material to prepare a laminated composite foam composite material. The composite board has excellent sound absorption and heat insulation Performance, the foam matrix material after fiber reinforcement has excellent mechanical properties; CN104371269A has reported a kind of high-strength phenolic foam and its preparation method, prepares high-strength phenolic foam by introducing the bamboo fiber modified by silane coupling agent in phenolic foam Plastic, the phenolic foam has excellent flame retardancy, heat resistance and solvent resistance, and has good mechanical strength.

However, most of the natural fibers used in the above documents are treated with coupling agents, and basically no flame retardant treatment is carried out. Even if the flame retardant treatment is carried out, it is only physically soaked with a flame retardant, and the modification effect is limited. In addition, the addition of natural fibers is small. The effect of improving the comprehensive performance of phenolic foam composite materials is limited; in addition, because nanocellulose is expensive, the use of nanocellulose to modify phenolic foam will increase the production cost of composite foam.

As one of the most abundant renewable resources in nature, cellulose has the advantages of low price, degradability, regular structure, easy chemical modification and special mechanical properties. It has been widely used in composite materials, textiles, drug delivery, and health care products. and membrane materials. By chemically modifying cellulose, a variety of functional polymers or functional groups can be grafted onto the main chain of cellulose, thereby broadening the application field of cellulose and increasing the added value of cellulose.

Contents of the invention

Technical problem to be solved: The present invention provides a preparation method of cellulose flame-retardant modified composite phenolic foam, which aims to improve the interfacial compatibility between cellulose and phenolic resin matrix, and greatly increase the amount of cellulose added in the composite foam. Solve the problem that it is difficult to mix evenly when adding cellulose in the later foaming process, improve the mechanical properties of the phenolic foam composite material, reduce the pulverization rate of the phenolic foam composite material, and improve the composite material without reducing the flame retardancy of the phenolic foam composite material. Comprehensive performance of phenolic foam.

Technical solution: A preparation method of cellulose flame-retardant modified composite phenolic foam, including the following two steps: 1) Preparation of DOPO-g-ITA: using xylene as solvent, under nitrogen protection, according to 9,10- Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and itaconic acid (ITA) react at a temperature of 120-130°C for 4-5 hours to obtain DOPO-g-ITA, DOPO and ITA The molar ratio is 1 to 1.3; 2) Preparation of DOPO-g-ITA modified cellulose: use xylene as solvent and K ₂ CO ₃ as catalyst, add cellulose into the reactor until the cellulose is completely dissolved in Add DOPO-g-ITA after toluene, the molar ratio of cellulose to DOPO-g-ITA is 1~ ₄ , the amount of K2CO3 added is 15~ ₂₀ % of the mass of cellulose, and the reaction temperature is 120~130℃ 8-9h, then suction-filtered, washed and dried at 60-65°C to obtain DOPO-g-ITA modified cellulose; 3) Preparation of flame-retardant grafted cellulose-modified phenolic resin: add 1mol phenol into the reaction vessel and DOPO-g-ITA modified cellulose which accounts for 2-30% of the mass of phenol, the temperature is raised to 90-95 ° C for 30-40 minutes, and then 0.45-0.55 mol of paraformaldehyde, 1.28 mol of water and 0.0025 mol of CaO are added, Keep at 90-95°C to continue the reaction for 30-40min. After the reaction, cool down to 85-90°C, add 0.675-0.825mol of paraformaldehyde and 0.06-0.08mol of 50wt.% NaOH solution, and react at 85-90°C for 50-70min. Then cool down to 80-85°C, add 0.675-0.825mol paraformaldehyde and 0.06-0.08mol 50wt.% NaOH solution, react at 80-85°C for 50-70min, then cool down to 75-80°C, add 0.03-0.04mol 50wt.% NaOH solution, react at 75-80°C for 30-40 minutes, cool down to below 40°C and discharge to obtain flame-retardant grafted cellulose-modified phenolic resin. During this process, the molar ratio of formaldehyde and phenol is controlled to be 1.8- 2.2, the molar ratio of 50wt.% NaOH and phenol is 0.15～0.2; 4) Preparation of flame-retardant grafted cellulose composite phenolic foam: adding curing agent, surfactant, and foaming agent into flame-retardant grafted cellulose Among them, in parts by weight: 100 parts of flame retardant grafted cellulose modified phenolic resin, 5 to 8 parts of surfactant, 20 to 30 parts of curing agent, and 5 to 8 parts of foaming agent ;Stir evenly, put it in the mold and foam and solidify at 60-70°C to obtain the flame-retardant modified fiber composite phenolic foam.

Preferably, in the above preparation of DOPO-g-ITA, the molar ratio of DOPO to ITA is 1.3.

Preferably, the cellulose used for the flame-retardant modification of the above-mentioned cellulose is ethyl cellulose or cellulose acetate.

Preferably, in the preparation of the above-mentioned DOPO-g-ITA modified cellulose, the molar ratio of cellulose to DOPO-g-ITA is 2-3.

Preferably, in the preparation of the above-mentioned DOPO-g-ITA modified cellulose, the addition amount of the catalyst K ₂ CO ₃ is 20% of the mass of the cellulose.

Preferably, in the preparation of the flame-retardant grafted cellulose-modified phenolic resin, the molar ratio of formaldehyde to phenol is 2.0.

Preferably, in the preparation of the flame-retardant grafted cellulose-modified phenolic resin, the molar ratio of the three batches of paraformaldehyde is 2:3:3.

Preferably, in the preparation of the flame-retardant grafted cellulose-modified phenolic resin, the molar ratio of 50wt.% NaOH to phenol is 0.15-0.17, and the molar ratio of the three batches is 1:1:0.5.

Preferably, in the preparation of the flame-retardant grafted cellulose-modified phenolic resin, the amount of DOPO-g-ITA modified cellulose added is 20-25% of the mass of phenol.

Beneficial effects: the present invention adopts flame retardant DOPO and ITA to carry out grafting reaction to prepare DOPO-g-ITA for modified cellulose, and then uses DOPO-g-ITA to flame-retardant graft cellulose, and is used to prepare DOPO-g-ITA g-ITA flame retardant grafted cellulose modified phenolic resin, and finally used in the preparation of cellulose composite phenolic foam. The interfacial compatibility between the modified cellulose prepared by the method of the present invention and the phenolic resin matrix is significantly improved, the cellulose modified phenolic resin has moderate viscosity and strong expandability, and the mechanical properties of the cellulose composite phenolic foam are significantly improved. The conversion rate is significantly reduced, and the flame retardancy is slightly improved; the amount of cellulose added in the composite foam is greatly increased, which solves the problem that it is difficult to mix the cellulose added in the later foaming process, and at the same time, the addition of a large amount of cellulose can reduce the composite foam. The production cost is beneficial to the popularization and application of the phenolic foam composite material.

detailed description

The cellulose in the embodiment of the present invention is DOPO-g-ITA flame-retardant modified ethyl cellulose or cellulose acetate respectively; In the embodiment, the phenolic resin is a high solid content flame-retardant grafted cellulose modified phenolic resin, solid Content is about 75wt.%; Surfactant is polysorbate-80 among the embodiment; Solidifying agent is the mixed acid of hydrochloric acid, phosphoric acid, p-toluenesulfonic acid and water compound in the embodiment, hydrochloric acid, phosphoric acid, p-toluenesulfonic acid The mass ratio to water is =8:4:6:3; the foaming agent in the examples is petroleum ether, with a boiling point of 30-60°C; the "parts" described in each example represent parts by mass. The present invention will be further described below in conjunction with embodiment.

Example 1

(1) Preparation of DOPO-g-ITA: Using xylene as solvent, under nitrogen protection, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- Add oxide (DOPO) and itaconic acid (ITA) into the reactor, reflux at 120°C for 4 hours, cool to 110°C, filter with suction, wash with acetone several times, and dry to obtain DOPO-g-ITA solid White powder. (2) Preparation of DOPO-g-ITA flame retardant grafted ethyl cellulose: dissolve the dried ethyl cellulose (water content <5%) in xylene solution (solid-to-liquid mass ratio is 1:20), Until it is completely dissolved, then add DOPO-g-ITA and K ₂ CO ₃ accounting for 15% of the mass of cellulose according to the molar ratio of ethyl cellulose and DOPO-g-ITA of 1:1, react at 120°C for 8 hours, then suction filter, Wash and dry at 60°C to obtain DOPO-g-ITA flame-retardant grafted ethyl cellulose.

(3) Preparation of flame retardant grafted ethyl cellulose modified phenolic resin: according to the molar ratio of formaldehyde and phenol is 1.8:1, the molar ratio of 50wt.% NaOH and phenol is 0.15:1, add 1mol in the reaction vessel Phenol and DOPO-g-ITA modified ethyl cellulose, which accounted for 2% of the mass of phenol, were heated to 90-95°C for 30-40 minutes, and then 0.45mol of paraformaldehyde, 1.28mol of water and 0.0025mol of CaO were added to keep Continue to react at 90-95°C for 30-40min, after the reaction, cool down to 85-90°C, add 0.675mol paraformaldehyde and 0.06mol 50wt.% NaOH solution, react at 85-90°C for 50-70min, then cool down to 80-90°C 85°C, add 0.675mol paraformaldehyde and 0.06mol 50wt.% NaOH solution, react at 80-85°C for 50-70min, then cool down to 75-80°C, add 0.03mol 50wt.% NaOH solution, React for 30-40 minutes, cool down to below 40°C and discharge to obtain flame-retardant grafted cellulose-modified phenolic resin;

(4) Preparation of flame-retardant modified ethyl cellulose composite phenolic foam: Add curing agent, surfactant, and foaming agent in proportion to the above-mentioned flame-retardant grafted ethyl cellulose modified phenolic resin, and stir evenly , placed in a mold at 70°C for foaming and solidification to obtain a flame-retardant modified ethyl cellulose composite phenolic foam. The raw material formula is calculated in parts by weight, consisting of: 100 parts of flame-retardant grafted ethyl cellulose modified phenolic resin; 5 parts of surfactant; 20 parts of curing agent; 5 parts of foaming agent; Table 1.

Example 2

(1) Preparation of DOPO-g-ITA: Using xylene as solvent, under nitrogen protection, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- Add oxide (DOPO) and itaconic acid (ITA) into the reactor, reflux reaction at 125°C for 4.5h, cool to 110°C, wash with acetone several times after suction filtration, and obtain DOPO-g-ITA after drying Solid white powder.

(2) Preparation of DOPO-g-ITA flame retardant grafted ethyl cellulose: dissolve the dried ethyl cellulose (water content <5%) in xylene solution (solid-to-liquid mass ratio is 1:20), Until it is completely dissolved, then add DOPO-g-ITA and 17% K ₂ CO ₃ according to the molar ratio of ethyl cellulose and DOPO-g-ITA is 2:1, react at 125°C for 8.5h, then suction filter and wash at 65°C Dry to obtain DOPO-g-ITA flame-retardant grafted ethyl cellulose.

(3) Preparation of flame retardant grafted ethyl cellulose modified phenolic resin: according to the molar ratio of formaldehyde and phenol is 2.0:1, the molar ratio of 50wt.% NaOH and phenol is 0.16:1, add 1mol phenol and DOPO-g-ITA modified ethyl cellulose accounting for 10% of the mass of phenol, heated to 93°C for 35 minutes, then added 0.5mol paraformaldehyde, 1.42mol water and 0.0025mol CaO, and kept at 93°C for 35 minutes After the reaction, cool down to 87°C, add 0.75mol paraformaldehyde and 0.064mol 50wt.% NaOH solution in proportion, react at 87°C for 60min, then cool down to 83°C, add 0.75mol paraformaldehyde and 0.064mol 50wt. % NaOH solution, react at 83°C for 60min, then cool down to 78°C, add 0.032mol 50wt.% NaOH solution, react at 78°C for 35min, cool down to below 40°C and discharge to obtain flame retardant grafted cellulose modified phenolic resin ;

(4) Preparation of flame-retardant modified ethyl cellulose composite phenolic foam: Add curing agent, surfactant, and foaming agent in proportion to the above-mentioned flame-retardant grafted ethyl cellulose modified phenolic resin, and stir evenly , placed in a mold at 70°C for foaming and solidification to obtain a flame-retardant modified ethyl cellulose composite phenolic foam. The raw material formula is calculated in parts by weight, consisting of: 100 parts of flame-retardant grafted ethyl cellulose modified phenolic resin; 6 parts of surfactant; 24 parts of curing agent; 6 parts of foaming agent; Table 1.

Example 3

(1) Preparation of DOPO-g-ITA: Using xylene as solvent, under nitrogen protection, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- Add oxide (DOPO) and itaconic acid (ITA) into the reactor, reflux at 130°C for 5 hours, cool to 110°C, filter with suction, wash with acetone several times, and dry to obtain DOPO-g-ITA solid White powder.

(2) Preparation of DOPO-g-ITA flame retardant grafted ethyl cellulose: dissolve the dried ethyl cellulose (water content <5%) in xylene solution (solid-to-liquid mass ratio is 1:20), Until it is completely dissolved, then add DOPO-g-ITA and 20% K ₂ CO ₃ according to the molar ratio of ethyl cellulose and DOPO-g-ITA is 3:1, react at 130°C for 9h, then suction filter, wash and dry at 70°C Dry to obtain DOPO-g-ITA flame-retardant grafted ethyl cellulose.

(3) Preparation of flame retardant grafted ethyl cellulose modified phenolic resin: according to the molar ratio of formaldehyde and phenol is 2.2:1, the molar ratio of 50wt.% NaOH and phenol is 0.17:1, add 1mol phenol and phenol DOPO-g-ITA modified ethyl cellulose with 20% mass was heated to 95°C for 40 minutes, then added 0.55mol paraformaldehyde, 1.56mol water and 0.0025mol CaO, kept at 95°C for 40 minutes, and cooled down after the reaction To 90°C, add 0.825mol paraformaldehyde and 0.068mol 50wt.% NaOH solution, react at 90°C for 70min, then cool down to 85°C, add 0.825mol paraformaldehyde and 0.068mol 50wt.% NaOH solution, react at 85°C 70 minutes, then lower the temperature to 80°C, add 0.034mol 50wt.% NaOH solution, react at 80°C for 40 minutes, cool down to below 40°C and discharge to obtain the flame-retardant grafted cellulose-modified phenolic resin;

(4) Preparation of flame-retardant modified ethyl cellulose composite phenolic foam: Add curing agent, surfactant, and foaming agent in proportion to the above-mentioned flame-retardant grafted ethyl cellulose modified phenolic resin, and stir evenly , placed in a mold at 70°C for foaming and solidification to obtain a flame-retardant modified ethyl cellulose composite phenolic foam. The raw material formula is calculated in parts by weight, consisting of: 100 parts of flame-retardant grafted ethyl cellulose modified phenolic resin; 7 parts of surfactant; 26 parts of curing agent; 7 parts of foaming agent; Table 1.

Example 4

(1) Preparation of DOPO-g-ITA: Using xylene as solvent, under nitrogen protection, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- Add oxide (DOPO) and itaconic acid (ITA) into the reactor, reflux at 130°C for 5 hours, cool to 110°C, filter with suction, wash with acetone several times, and dry to obtain DOPO-g-ITA solid White powder.

(2) Preparation of DOPO-g-ITA flame retardant grafted ethyl cellulose: dissolve the dried ethyl cellulose (water content <5%) in xylene solution (solid-to-liquid mass ratio is 1:20), Until it is completely dissolved, then add DOPO-g-ITA and 20% K ₂ CO ₃ according to the molar ratio of ethyl cellulose and DOPO-g-ITA is 4:1, react at 130°C for 9h, then suction filter, wash and dry at 60°C Dry to obtain DOPO-g-ITA flame-retardant grafted ethyl cellulose.

(3) Preparation of flame retardant grafted ethyl cellulose modified phenolic resin: according to the molar ratio of formaldehyde and phenol is 2.2:1, the molar ratio of 50wt.% NaOH and phenol is 0.2:1, add 1mol phenol and phenol DOPO-g-ITA modified ethyl cellulose with a mass of 30% was heated to 95°C for 40 minutes, then added 0.55mol paraformaldehyde, 1.56mol water and 0.0025mol CaO, kept at 95°C for 40 minutes, and cooled to 90°C, add 0.825mol paraformaldehyde and 0.08mol50wt.% NaOH solution, react at 90°C for 70min, then cool down to 85°C, add 0.825mol paraformaldehyde and 0.08mol50wt.%NaOH solution, react at 85°C for 70min, then Cool down to 80°C, add 0.04mol 50wt.% NaOH solution, react at 80°C for 40 minutes, cool down to below 40°C and discharge to obtain flame-retardant grafted cellulose-modified phenolic resin;

(4) Preparation of flame-retardant modified ethyl cellulose composite phenolic foam: Add curing agent, surfactant, and foaming agent in proportion to the above-mentioned flame-retardant grafted ethyl cellulose modified phenolic resin, and stir evenly , placed in a mold at 70°C for foaming and solidification to obtain a flame-retardant modified ethyl cellulose composite phenolic foam. The raw material formula is calculated in parts by weight, consisting of: 100 parts of flame-retardant grafted ethyl cellulose modified phenolic resin; 8 parts of surfactant; 30 parts of curing agent; 8 parts of foaming agent; Table 1.

Example 5

(1) Preparation of DOPO-g-ITA: Using xylene as solvent, under nitrogen protection, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- Add oxide (DOPO) and itaconic acid (ITA) into the reactor, reflux at 130°C for 5 hours, cool to 110°C, filter with suction, wash with acetone several times, and dry to obtain DOPO-g-ITA solid White powder.

(2) Preparation of DOPO-g-ITA flame retardant grafted ethyl cellulose: dissolve the dried ethyl cellulose (water content <5%) in xylene solution (solid-to-liquid mass ratio is 1:20), Until it is completely dissolved, then add DOPO-g-ITA and 20% K ₂ CO ₃ according to the molar ratio of ethyl cellulose and DOPO-g-ITA is 2:1, react at 130°C for 9h, then suction filter, wash and dry at 60°C Dry to obtain DOPO-g-ITA flame-retardant grafted ethyl cellulose.

(3) Preparation of flame retardant grafted ethyl cellulose modified phenolic resin: according to the molar ratio of formaldehyde and phenol is 2.0:1, the molar ratio of 50wt.% NaOH and phenol is 0.15:1, add 1mol phenol and DOPO-g-ITA modified ethyl cellulose accounting for 20% of the mass of phenol, heated up to 93°C for 35 minutes, then added 0.5mol paraformaldehyde, 1.42mol water and 0.0025mol CaO, and kept at 93°C for 35 minutes After the reaction, cool down to 87°C, add 0.6mol paraformaldehyde and 0.064mol 50wt.% NaOH solution in proportion, react at 87°C for 60min, then cool down to 83°C, add 0.75mol paraformaldehyde and 0.06mol 50wt. % NaOH solution, react at 83°C for 60min, then cool down to 78°C, add 0.03mol 50wt.% NaOH solution, react at 78°C for 35min, cool down to below 40°C and discharge to obtain flame retardant grafted cellulose modified phenolic resin ;

(4) Preparation of flame-retardant modified ethyl cellulose composite phenolic foam: Add curing agent, surfactant, and foaming agent in proportion to the above-mentioned flame-retardant grafted ethyl cellulose modified phenolic resin, and stir evenly , placed in a mold at 70°C for foaming and solidification to obtain a flame-retardant modified ethyl cellulose composite phenolic foam. The raw material formula is calculated in parts by weight, consisting of: 100 parts of flame-retardant grafted ethyl cellulose modified phenolic resin; 5 parts of surfactant; 20 parts of curing agent; 5 parts of foaming agent; Table 1.

Example 6

(1) Preparation of DOPO-g-ITA: using xylene as solvent, under the protection of nitrogen, an appropriate amount of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10 -Oxide (DOPO) and itaconic acid (ITA) were added into the reactor, reflux at 130°C for 5 hours, cooled to 110°C, filtered with suction, washed several times with acetone, and dried to obtain DOPO-g-ITA Solid white powder.

(2) Preparation of DOPO-g-ITA flame retardant grafted ethyl cellulose: dissolve the dried ethyl cellulose (water content <5%) in xylene solution (solid-to-liquid mass ratio is 1:20), Until it is completely dissolved, then add DOPO-g-ITA and 20% K ₂ CO ₃ according to the molar ratio of ethyl cellulose and DOPO-g-ITA is 3:1, react at 130°C for 9h, then suction filter, wash and dry at 60°C Dry to obtain DOPO-g-ITA flame-retardant grafted ethyl cellulose.

(3) Preparation of flame retardant grafted ethyl cellulose modified phenolic resin: according to the molar ratio of formaldehyde and phenol is 2.0:1, the molar ratio of 50wt.% NaOH and phenol is 0.17:1, add 1mol phenol and DOPO-g-ITA modified ethyl cellulose accounting for 25% of the mass of phenol, heated to 93°C for 35 minutes, then added 0.5mol paraformaldehyde, 1.42mol water and 0.0025mol CaO, and kept at 93°C for 35 minutes After the reaction, cool down to 87°C, add 0.6mol paraformaldehyde and 0.068mol 50wt.% NaOH solution in proportion, react at 87°C for 60min, then cool down to 83°C, add 0.75mol paraformaldehyde and 0.068mol 50wt. % NaOH solution, react at 83°C for 60min, then cool down to 78°C, add 0.034mol 50wt.% NaOH solution, react at 78°C for 35min, cool down to below 40°C and discharge to obtain flame retardant grafted cellulose modified phenolic resin ;

(4) Preparation of flame-retardant modified ethyl cellulose composite phenolic foam: Add curing agent, surfactant, and foaming agent in proportion to the above-mentioned flame-retardant grafted ethyl cellulose modified phenolic resin, and stir evenly , placed in a mold at 70°C for foaming and solidification to obtain a flame-retardant modified ethyl cellulose composite phenolic foam. The raw material formula is calculated in parts by weight, consisting of: 100 parts of flame-retardant grafted ethyl cellulose modified phenolic resin; 8 parts of surfactant; 30 parts of curing agent; 8 parts of foaming agent; Table 1.

Example 7

(1) Preparation of DOPO-g-ITA: Using xylene as solvent, under nitrogen protection, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- Add oxide (DOPO) and itaconic acid (ITA) into the reactor, reflux at 120°C for 4 hours, cool to 110°C, filter with suction, wash with acetone several times, and dry to obtain DOPO-g-ITA solid White powder.

(2) Preparation of DOPO-g-ITA flame-retardant grafted cellulose acetate: dissolve the dried cellulose acetate (water content <5%) in xylene solution (solid-to-liquid mass ratio is 1:20) until completely Dissolve, then add DOPO-g-ITA and 15% K ₂ CO ₃ according to the 1:1 molar ratio of cellulose acetate and DOPO-g-ITA, react at 120°C for 8 hours, then suction filter, wash and dry at 60°C to obtain DOPO-g-ITA flame retardant grafted cellulose acetate.

(3) Preparation of flame retardant grafted cellulose acetate modified phenolic resin: according to the molar ratio of formaldehyde and phenol is 1.8:1, the molar ratio of 50wt.% NaOH and phenol is 0.15:1, add 1mol phenol in the reaction vessel and DOPO-g-ITA modified cellulose acetate which accounts for 2% of the mass of phenol, the temperature is raised to 90-95°C for 30-40 minutes, and then 0.45mol of paraformaldehyde, 1.28mol of water and 0.0025mol of CaO are added, and the temperature is maintained at 90-95°C. Continue to react at 95°C for 30-40min, after the reaction is over, cool down to 85-90°C, add 0.675mol paraformaldehyde and 0.06mol 50wt.% NaOH solution, react at 85-90°C for 50-70min, then cool down to 80-85°C , add 0.675mol paraformaldehyde and 0.06mol 50wt.% NaOH solution, react at 80-85°C for 50-70min, then cool down to 75-80°C, add 0.03mol 50wt.% NaOH solution, react at 75-80°C for 30 minutes ~40min, cooling down to below 40°C and discharging to obtain the flame-retardant grafted cellulose-modified phenolic resin;

(4) Preparation of flame-retardant modified cellulose acetate composite phenolic foam: Add curing agent, surfactant, and blowing agent in the above-mentioned flame-retardant grafted cellulose acetate modified phenolic resin in proportion, and stir evenly, place Foam and solidify in a mold at 70°C to obtain a flame-retardant modified cellulose acetate composite phenolic foam. The raw material formula is in parts by weight, and the composition is: 100 parts of flame-retardant grafted cellulose acetate modified phenolic resin; 5 parts of surfactant; 20 parts of curing agent; 5 parts of foaming agent; see the attached table for material properties 1.

Example 8

(1) Preparation of DOPO-g-ITA: Using xylene as solvent, under nitrogen protection, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- Add oxide (DOPO) and itaconic acid (ITA) into the reactor, reflux reaction at 125°C for 4.5h, cool to 110°C, wash with acetone several times after suction filtration, and obtain DOPO-g-ITA after drying Solid white powder.

(2) Preparation of DOPO-g-ITA flame-retardant grafted cellulose acetate: dissolve the dried cellulose acetate (water content <5%) in xylene solution (solid-to-liquid mass ratio is 1:20) until completely Dissolve, then add DOPO-g-ITA and 17% K ₂ CO ₃ according to the molar ratio of cellulose acetate and DOPO-g-ITA at 2:1, react at 125°C for 8.5h, then suction filter, wash and dry at 65°C Obtain DOPO-g-ITA flame-retardant grafted cellulose acetate.

(3) Preparation of flame retardant grafted cellulose acetate modified phenolic resin: according to the mol ratio of formaldehyde and phenol is 2.0:1, the mol ratio of 50wt.% NaOH and phenol is 0.16:1, in the reactor, add 1mol Phenol and DOPO-g-ITA modified cellulose acetate accounting for 10% of the mass of phenol, heated up to 93°C for 35 minutes, then added 0.5mol of paraformaldehyde, 1.42mol of water and 0.0025mol of CaO, and kept at 93°C for 35 minutes. After the end, cool down to 87°C, add 0.75mol paraformaldehyde and 0.064mol 50wt.% NaOH solution in proportion, react at 87°C for 60min, then cool down to 83°C, add 0.75mol paraformaldehyde and 0.064mol 50wt.%NaOH Solution, reacted at 83°C for 60 minutes, then cooled to 78°C, added 0.032mol 50wt.% NaOH solution, reacted at 78°C for 35 minutes, cooled to below 40°C and discharged to obtain a flame-retardant grafted cellulose-modified phenolic resin;

(4) Preparation of flame-retardant modified cellulose acetate composite phenolic foam: Add curing agent, surfactant, and blowing agent in the above-mentioned flame-retardant grafted cellulose acetate modified phenolic resin in proportion, and stir evenly, place Foam and solidify in a mold at 70°C to obtain a flame-retardant modified cellulose acetate composite phenolic foam. The raw material formula is in parts by weight, and the composition is: 100 parts of flame-retardant grafted cellulose acetate modified phenolic resin; 6 parts of surfactant; 23 parts of curing agent; 7 parts of foaming agent; see the attached table for material properties 1.

Example 9

(1) Preparation of DOPO-g-ITA: Using xylene as solvent, under nitrogen protection, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- Add oxide (DOPO) and itaconic acid (ITA) into the reactor, reflux at 130°C for 5 hours, cool to 110°C, filter with suction, wash with acetone several times, and dry to obtain DOPO-g-ITA solid White powder.

(2) Preparation of DOPO-g-ITA flame-retardant grafted cellulose acetate: dissolve the dried ethyl cellulose (water content<5%) in xylene solution (solid-to-liquid mass ratio is 1:20) until Dissolve completely, then add DOPO-g-ITA and 20% K ₂ CO ₃ according to the molar ratio of cellulose acetate and DOPO-g-ITA of 3:1, react at 130°C for 9 hours, then suction filter, wash and dry at 70°C Obtain DOPO-g-ITA flame-retardant grafted cellulose acetate.

(3) Preparation of flame retardant grafted cellulose acetate modified phenolic resin: according to the molar ratio of formaldehyde and phenol is 2.2:1, the molar ratio of 50wt.% NaOH and phenol is 0.18:1, add 1mol phenol and account for the mass of phenol 20% DOPO-g-ITA modified cellulose acetate, heated to 95°C for 40 minutes, then added 0.55mol paraformaldehyde, 1.56mol water and 0.0025mol CaO, kept at 95°C for 40 minutes, cooled to 90°C after the reaction ℃, add 0.825mol paraformaldehyde and 0.072mol 50wt.% NaOH solution, react at 90℃ for 70min, then cool down to 85℃, add 0.825mol paraformaldehyde and 0.072mol 50wt.%NaOH solution, react at 85℃ for 70min, Then lower the temperature to 80°C, add 0.036mol 50wt.% NaOH solution, react at 80°C for 40 minutes, cool down to below 40°C and discharge to obtain the flame-retardant grafted cellulose-modified phenolic resin;

(4) Preparation of flame-retardant modified cellulose acetate composite phenolic foam: Add curing agent, surfactant, and blowing agent in the above-mentioned flame-retardant grafted cellulose acetate modified phenolic resin in proportion, and stir evenly, place Foam and solidify in a mold at 70°C to obtain a flame-retardant modified cellulose acetate composite phenolic foam. The raw material formula is in parts by weight, and the composition is: 100 parts of flame-retardant grafted cellulose acetate modified phenolic resin; 7 parts of surfactant; 26 parts of curing agent; 7 parts of foaming agent; see the attached table for material properties 1.

Example 10

(1) Preparation of DOPO-g-ITA: Using xylene as solvent, under nitrogen protection, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- Add oxide (DOPO) and itaconic acid (ITA) into the reactor, reflux at 130°C for 5 hours, cool to 110°C, filter with suction, wash with acetone several times, and dry to obtain DOPO-g-ITA solid White powder.

(2) Preparation of DOPO-g-ITA flame-retardant grafted cellulose acetate: dissolve the dried cellulose acetate (water content <5%) in xylene solution (solid-to-liquid mass ratio is 1:20) until completely Dissolve, then add DOPO-g-ITA and 20% K ₂ CO ₃ according to the molar ratio of cellulose acetate and DOPO-g-ITA is 4:1, react at 130°C for 9 hours, then suction filter, wash and dry at 60°C to obtain DOPO-g-ITA flame retardant grafted cellulose acetate.

(3) Preparation of flame retardant grafted cellulose acetate modified phenolic resin: according to the molar ratio of formaldehyde and phenol is 2.2:1, the molar ratio of 50wt.% NaOH and phenol is 0.2:1, add 1mol phenol and account for the mass of phenol 30% DOPO-g-ITA modified cellulose acetate, heat up to 95°C for 40 minutes, then add 0.55mol paraformaldehyde, 1.56mol water and 0.0025mol CaO, keep 95°C for 40 minutes, cool down to 90°C after the reaction , add 0.825mol paraformaldehyde and 0.08mol50wt.% NaOH solution, react at 90°C for 70min, then cool down to 85°C, add 0.825mol paraformaldehyde and 0.08mol50wt.%NaOH solution, react at 85°C for 70min, then cool down to 80°C, add 0.04mol 50wt.% NaOH solution, react at 80°C for 40 minutes, cool down to below 40°C and discharge to obtain the flame-retardant grafted cellulose-modified phenolic resin;

(4) Preparation of flame-retardant modified cellulose acetate composite phenolic foam: Add curing agent, surfactant, and blowing agent in the above-mentioned flame-retardant grafted cellulose acetate modified phenolic resin in proportion, and stir evenly, place Foam and solidify in a mold at 70°C to obtain a flame-retardant modified cellulose acetate composite phenolic foam. The raw material formula is in parts by weight, and the composition is: 100 parts of flame-retardant grafted cellulose acetate modified phenolic resin; 8 parts of surfactant; 30 parts of curing agent; 8 parts of foaming agent; see the attached table for material properties 1.

Example 11

(1) Preparation of DOPO-g-ITA: Using xylene as solvent, under nitrogen protection, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- Add oxide (DOPO) and itaconic acid (ITA) into the reactor, reflux at 130°C for 5 hours, cool to 110°C, filter with suction, wash with acetone several times, and dry to obtain DOPO-g-ITA solid White powder.

(2) Preparation of DOPO-g-ITA flame-retardant grafted cellulose acetate: dissolve the dried cellulose acetate (water content <5%) in xylene solution (solid-to-liquid mass ratio is 1:20) until completely Dissolve, then add DOPO-g-ITA and 20% K ₂ CO ₃ according to the molar ratio of cellulose acetate and DOPO-g-ITA at 2:1, react at 130°C for 9 hours, then suction filter, wash and dry at 60°C to obtain DOPO-g-ITA flame retardant grafted cellulose acetate.

(3) Preparation of flame retardant grafted cellulose acetate modified phenolic resin: according to the mol ratio of formaldehyde and phenol is 2.0:1, the mol ratio of 50wt.%NaOH and phenol is 0.15:1, in the reactor, add 1mol Phenol and DOPO-g-ITA modified cellulose acetate accounting for 20% of the mass of phenol were heated to 93°C for 35 minutes, then 0.5mol paraformaldehyde, 1.42mol water and 0.0025mol CaO were added, and the reaction was continued at 93°C for 35 minutes. After the end, cool down to 87°C, add 0.75mol paraformaldehyde and 0.06mol 50wt.% NaOH solution in proportion, react at 87°C for 60min, then cool down to 83°C, add 0.75mol paraformaldehyde and 0.06mol 50wt.%NaOH Solution, reacted at 83°C for 60 minutes, then cooled to 78°C, added 0.03mol 50wt.% NaOH solution, reacted at 78°C for 35 minutes, cooled to below 40°C and discharged to obtain a flame-retardant grafted cellulose-modified phenolic resin;

(4) Preparation of flame-retardant modified cellulose acetate composite phenolic foam: Add curing agent, surfactant, and blowing agent in the above-mentioned flame-retardant grafted cellulose acetate modified phenolic resin in proportion, and stir evenly, place Foam and solidify in a mold at 70°C to obtain a flame-retardant modified cellulose acetate composite phenolic foam. The raw material formula is in parts by weight, and the composition is: 100 parts of flame-retardant grafted cellulose acetate modified phenolic resin; 8 parts of surfactant; 30 parts of curing agent; 8 parts of foaming agent; see the attached table for material properties 1.

Example 12

(1) Preparation of DOPO-g-ITA: using xylene as solvent, under the protection of nitrogen, an appropriate amount of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10 -Oxide (DOPO) and itaconic acid (ITA) were added into the reactor, reflux at 130°C for 5 hours, cooled to 110°C, filtered with suction, washed several times with acetone, and dried to obtain DOPO-g-ITA Solid white powder.

(2) Preparation of DOPO-g-ITA flame-retardant grafted cellulose acetate: dissolve the dried cellulose acetate (water content <5%) in xylene solution (solid-to-liquid mass ratio is 1:20) until completely Dissolve, then add DOPO-g-ITA and 20% K ₂ CO ₃ according to the molar ratio of cellulose acetate and DOPO-g-ITA at 3:1, react at 130°C for 9 hours, then suction filter, wash and dry at 60°C to obtain DOPO-g-ITA flame retardant grafted cellulose acetate.

(3) Preparation of flame retardant grafted cellulose acetate modified phenolic resin: according to the mol ratio of formaldehyde and phenol is 2.0:1, the mol ratio of 50wt.% NaOH and phenol is 0.17:1, in the reactor, add 1mol Phenol and DOPO-g-ITA modified cellulose acetate accounting for 25% of the mass of phenol were heated up to 93°C for 35 minutes, then 0.5mol paraformaldehyde, 1.42mol water and 0.0025mol CaO were added, and the reaction was continued at 93°C for 35 minutes. After the end, cool down to 87°C, add 0.75mol paraformaldehyde and 0.068mol 50wt.% NaOH solution in proportion, react at 87°C for 60min, then cool down to 83°C, add 0.75mol paraformaldehyde and 0.068mol 50wt.%NaOH Solution, reacted at 83°C for 60 minutes, then cooled to 78°C, added 0.034mol 50wt.% NaOH solution, reacted at 78°C for 35 minutes, cooled to below 40°C and discharged to obtain a flame-retardant grafted cellulose-modified phenolic resin;

(4) Preparation of flame-retardant modified cellulose acetate composite phenolic foam: Add curing agent, surfactant, and blowing agent in the above-mentioned flame-retardant grafted cellulose acetate modified phenolic resin in proportion, and stir evenly, place Foam and solidify in a mold at 70°C to obtain a flame-retardant modified cellulose acetate composite phenolic foam. The raw material formula is in parts by weight, and the composition is: 100 parts of flame-retardant grafted cellulose acetate modified phenolic resin; 5 parts of surfactant; 20 parts of curing agent; 5 parts of foaming agent; see the attached table for material properties 1.

The properties of cellulose modified phenolic resin and foam material of different formulations in table 1

When the molar ratio of formaldehyde and phenol is 2.0:1, the amount of DOPO-g-ITA modified cellulose is 20% to 25%, and the molar ratio of 50wt.% NaOH solution to phenol is 0.15 to 0.17, the prepared cellulose modified The viscosity and solid content of the non-toxic phenolic resin are moderate, and the foamability is strong; when the flame-retardant grafted cellulose modified phenolic resin is 100 parts, the surfactant is 5 parts, the curing agent is 20 parts, and the foaming agent is 5 parts. The apparent density of the modified cellulose composite phenolic foam is moderate, the oxygen index and bending and compressive strength are high, the pulverization rate is low, and the comprehensive performance of the composite foam is better.

Claims (9)

1. a kind of preparation method of the flame-retardant modified composite phenol formaldehyde foam of cellulose, it is characterised in that including following two steps：1） DOPO-g-ITA preparation：Using dimethylbenzene as solvent, under nitrogen protection, according to the miscellaneous -10- phospho hetero phenanthrenes of 9,10- dihydro-9-oxies - 10- oxides（DOPO）With itaconic acid（ITA）It is that 120 ~ 130 DEG C of 4 ~ 5h of reaction produce DOPO-g-ITA, DOPO and ITA in temperature Mol ratio is 1 ~ 1.3；2）The preparation of DOPO-g-ITA modified celluloses：Using dimethylbenzene as solvent, with K₂CO₃For catalyst, by fibre Dimension element is added in reactor, and DOPO-g-ITA, cellulose and DOPO-g-ITA are added after cellulose is dissolved completely in dimethylbenzene Mol ratio be 1 ~ 4, K₂CO₃Addition be cellulose quality 15 ~ 20%, temperature be 120 ~ 130 DEG C reaction 8 ~ 9h, then Filter, wash in 60 ~ 65 DEG C of drying, both obtain DOPO-g-ITA modified celluloses；3）Fire-retardant grafted cellulose phenol-formaldehyde resin modified Preparation：It is 2 ~ 30% DOPO-g-ITA modified celluloses that 1mol phenol is added in reaction vessel with the quality for accounting for phenol, is risen Temperature adds 0.45 ~ 0.55 mol paraformaldehydes, 1.28 mol water and 0.0025mol afterwards to 90 ~ 95 DEG C of 30 ~ 40min of reaction CaO, kept for 90 ~ 95 DEG C continue 30 ~ 40min of reaction, reaction is cooled to 85 ~ 90 DEG C after terminating, it is more to add 0.675 ~ 0.825mol Polyformaldehyde and 0.06 ~ 0.08 mol 50wt.% NaOH solutions, 50 ~ 70min is reacted in 85-90 DEG C, is then cooled to 80 ~ 85 DEG C, 0.675 ~ 0.825mol paraformaldehydes and 0.06 ~ 0.08mol 50wt.% NaOH solutions are added, react 50 in 80 ~ 85 DEG C ~ 70min, is then cooled to 75 ~ 80 DEG C, adds 0.03 ~ 0.04mol 50wt.% NaOH solutions, react 30 in 75 ~ 80 DEG C ~ 40min, cooling down produce fire-retardant grafted cellulose phenol-formaldehyde resin modified to 40 DEG C with bottom discharge, control formaldehyde during this Mol ratio with phenol is 1.8 ~ 2.2,50wt.% NaOH and the mol ratio of phenol is 0.15 ~ 0.2；4）Fire-retardant grafted cellulose The preparation of composite phenol formaldehyde foam：Curing agent, surfactant and foaming agent are added into fire-retardant grafted cellulose phenol-formaldehyde resin modified In, wherein by weight：Fire-retardant grafted cellulose phenol-formaldehyde resin modified is 100 parts, surfactant is 5~8 parts, curing agent It it is 5~8 parts for 20~30 parts, foaming agent；Stir, be placed in mould in 60~70 DEG C of foamed solidifications, produce flame-retardant modified Fiber composite phenol formaldehyde foam.

A kind of 2. preparation method of the flame-retardant modified composite phenol formaldehyde foam of cellulose according to claim 1, it is characterised in that In the preparation of the DOPO-g-ITA, DOPO is 1.3 with ITA mol ratios.

A kind of 3. preparation method of the flame-retardant modified composite phenol formaldehyde foam of cellulose according to claim 1, it is characterised in that The flame-retardant modified cellulose used of the cellulose is ethyl cellulose or cellulose acetate.

A kind of 4. preparation method of the flame-retardant modified composite phenol formaldehyde foam of cellulose according to claim 1, it is characterised in that In the preparation of the DOPO-g-ITA modified celluloses, cellulose and DOPO-g-ITA mol ratio are 2 ~ 3.

A kind of 5. preparation method of the flame-retardant modified composite phenol formaldehyde foam of cellulose according to claim 1, it is characterised in that In the preparation of the DOPO-g-ITA modified celluloses, catalyst K₂CO₃Addition be cellulose quality 20%.

A kind of 6. preparation method of the flame-retardant modified composite phenol formaldehyde foam of cellulose according to claim 1, it is characterised in that In the preparation of the fire-retardant grafted cellulose phenol-formaldehyde resin modified, the mol ratio of formaldehyde and phenol is 2.0.

A kind of 7. preparation method of the flame-retardant modified composite phenol formaldehyde foam of cellulose according to claim 1, it is characterised in that In the preparation of the fire-retardant grafted cellulose phenol-formaldehyde resin modified, the mol ratio of three batch paraformaldehydes is 2:3:3.

A kind of 8. preparation method of the flame-retardant modified composite phenol formaldehyde foam of cellulose according to claim 1, it is characterised in that In the preparation of the fire-retardant grafted cellulose phenol-formaldehyde resin modified, the mol ratio of 50wt.% NaOH and phenol is 0.15 ~ 0.17, And three batch mol ratio be 1:1:0.5.

A kind of 9. preparation method of the flame-retardant modified composite phenol formaldehyde foam of cellulose according to claim 1, it is characterised in that In the preparation of the fire-retardant grafted cellulose phenol-formaldehyde resin modified, DOPO-g-ITA modified cellulose additions account for the quality of phenol For 20 ~ 25%.