CN106674499A - Rigid polyester engineering plastic with high smelting point and high glass-transition temperature and preparation method thereof - Google Patents

Abstract

The invention discloses a rigid polyester engineering plastic with a high melting point and a high glass transition temperature. The plastic is synthesized from raw materials including the following parts by weight: 1000-1200 parts of dicarboxylic acid monomer, 400-700 parts of dihydric alcohol monomer 100-350 parts of phenolphthalein, 0.5-2 parts of catalyst, 1-4 parts of stabilizer, and 1-8 parts of antioxidant. The plastic has excellent heat resistance and aging resistance, the preparation method is simple, and the service life can be extended. At the same time, it has good toughness, fatigue resistance, excellent environmental resistance, outstanding flame retardancy and low smoke generation. Ideal polymer materials used in high-tech fields such as electronic and electrical industries and machinery industries.

Description

A kind of rigid polyester engineering plastics with high melting point and high glass transition temperature and its preparation preparation method

technical field

The invention relates to the technical field of polyester synthesis, in particular to a rigid polyester engineering plastic with a high melting point and a high glass transition temperature and a manufacturing method thereof.

Background technique

Since 1941, J. R. Whenfield and J. T. Dikson in the United Kingdom used terephthalic acid and ethylene glycol as raw materials to synthesize polyethylene terephthalate and make polyester fibers for the first time. It has been more than 70 years of development so far. course. Polyester resin is mainly used to produce polyester fiber, and it is also widely used in light industry, machinery, electronics, food packaging and other industrial fields as non-fiber films, plastics, packaging containers, adhesives, and coating products. In order to meet the needs of the market, people have also developed and produced a large number of modified polyester varieties. In recent years, the world's polyester industry has developed rapidly, and the growth rate has been maintained at about 10% per year. In 2010, the output reached nearly 18 million tons. Nevertheless, its performance and functions are far from meeting the needs of economic development. Therefore, the research on high-performance polyester materials has always been one of the topics of concern in the industry.

With the continuous development of science and technology, cutting-edge industrial sectors such as aerospace, electronic communication and military have higher and higher requirements for "lightweight", "high temperature resistance" and "high performance" of fiber reinforced composite materials. At present, the advanced structural materials used in my country's aerospace and other high-tech fields are mainly thermosetting composite materials, but thermosetting composite materials generally have relatively low impact resistance and damage resistance, poor heat resistance, and high manufacturing costs. Therefore, there is an urgent need for new composite materials with higher heat resistance and good mechanical properties at high temperatures. High-performance thermoplastic resin-based composites have the advantages of good toughness, high resistance to fatigue damage and impact damage, short molding cycle, and recyclability, so they have received more and more attention.

Polyethylene naphthalate (PEN) is a new type of high-performance polyester material, which can be regarded as the product obtained by replacing the benzene rings in polyethylene terephthalate (PET) with naphthalene rings. Due to the conjugated structure of the naphthalene ring, the rigidity of the molecular main chain is significantly increased. Compared with the traditional PET, the glass transition temperature Tg of PEN is about 45 ° C higher than that of PET, reaching 120 ° C. It also has high barrier properties and small heat shrinkage. , Good dimensional stability and other significant advantages, which make PEN receive great attention and extensive research in the field of high-performance materials. However, the third monomer 2,6-naphthalene dicarboxylic acid used in the synthesis of PEN is expensive, which limits the application of PEN. People are urgently looking for a low-cost polyester engineering plastic material that can replace PEN.

Contents of the invention

The first object of the present invention is to provide a rigid polyester engineering plastic with a high melting point and a high glass transition temperature, which has excellent heat resistance, excellent toughness, fatigue resistance, excellent environmental resistance, outstanding The advantages of flame retardancy and low smoke emission.

The second object of the present invention is to provide a method for preparing the above-mentioned plastic.

The purpose of the present invention is specifically achieved through the following technical solutions:

A rigid polyester engineering plastic with a high melting point and a high glass transition temperature is synthesized from raw materials comprising the following parts by weight:

Diformic acid monomer 1000-1200 parts,

400-700 parts of diol monomer,

100-350 parts of phenolphthalein,

Catalyst 0.5-2 parts,

Stabilizer 1-4 parts,

Antioxidant 1-8 parts.

Further, the dicarboxylic acid monomer is one of terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid and biphenyl dicarboxylic acid;

The diol monomer is one of ethylene glycol, propylene glycol, and 1,4-cyclohexanedimethanol;

The catalyst is one of antimony series, titanium series and germanium series catalysts;

The stabilizer is one or more of phosphoric acid esters and phosphite esters;

The antioxidant is one or more of phenols, amines, phosphites, and sulfur-containing antioxidants.

Further, the mole number of the phenolphthalein is less than 50% of the mole number of the diol monomer.

Further, the plastic has a glass transition temperature ≥ 90°C, a melting point ≥ 250°C, an intrinsic viscosity ≥ 0.65dL/g, and a thermal decomposition temperature ≥ 490°C.

The preparation method of the above-mentioned rigid polyester engineering plastics with high melting point and high glass transition temperature comprises the following steps:

(1) Mix dicarboxylic acid monomer, diol monomer, phenolphthalein, catalyst and antioxidant evenly, add to the reaction kettle and stir, then heat for esterification reaction, when the esterification reaches more than 95%, the esterification The reaction is over;

(2) After the esterification reaction is finished, add a stabilizer to the product obtained in step (1), and carry out polycondensation reaction under vacuum;

(3) After the polycondensation reaction is completed, the material is discharged, cooled, and pelletized to obtain a rigid polyester engineering plastic with a high melting point and a high glass transition temperature.

Further, in the step (1), the stirring time is 30 minutes, and the temperature of the esterification reaction is 230-260°C;

In the step (2), the polycondensation reaction is carried out at a relative vacuum pressure ≥ -100kPa, the reaction temperature is 290-300°C, and the reaction time is 180-360min.

The present invention introduces the third monomer of phenolphthalein in the process of synthesizing the polyester, and replaces the flexible diethanol part in the polyester macromolecular chain with a rigid phenolphthalein group, thereby forming a combination of rigid diacid monomers and rigid phenolphthalein monomers. Fragments, enhance the rigidity and crystallization properties of the whole molecule, increase the glass transition temperature and melting point. At the same time, phenolphthalein contains large rigid side groups, which hinder the free rotation and relative sliding of the groups in the molecular chain, and further improve the crystallinity and heat resistance. By controlling the ratio of the diol monomer to the third phenolphthalein monomer, the glass transition temperature and melting point of the polyester plastic can also be effectively adjusted.

The beneficial effects of the present invention are:

The invention provides a rigid polyester engineering plastic with a high melting point and a high glass transition temperature, which has excellent heat resistance and aging resistance, a simple preparation method, can prolong the service life, and has good toughness and fatigue resistance. , excellent environmental resistance, outstanding flame retardancy and low smoke emission, it is an ideal polymer material used in high-tech fields such as electrical and electronic industries and machinery industries.

detailed description

Preferred embodiments of the present invention are described below, and it should be understood that the preferred embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

The raw materials of the present invention are all available on the market, wherein the antioxidant 1010 is tetrakis [β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester, manufacturer: Bailingwei Technology Co., Ltd., Antioxidant 626 is bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite, manufacturer: Qingdao Jiedejia New Material Technology Co., Ltd. Antioxidant 168 is tris[2.4-di-tert-butylphenyl ] Phosphite, manufacturer: Qingdao Jiedejia New Material Technology Co., Ltd.

Example 1

A rigid polyester engineering plastic with a high melting point and a high glass transition temperature and a preparation method thereof, which are synthesized from raw materials including 1200 g terephthalic acid, 500 g (8.06 mol) of ethylene glycol, and 100 g (0.31 mol) of phenolphthalein mol), antimony ethylene glycol 0.6 g, trimethyl phosphate 2 g, antioxidant 1010 3 g.

The production method of the rigid polyester engineering plastic with high melting point and high glass transition temperature comprises the following steps:

(1) Weigh terephthalic acid, ethylene glycol, phenolphthalein, ethylene glycol antimony catalyst and antioxidant 1010 and mix them evenly, add them to a 5 L reaction kettle, stir for 30 minutes, then turn off the stirring, and turn on the vacuum system slowly Extract the oxygen in the kettle, then pass nitrogen to normal pressure, repeat the vacuum pumping and nitrogen flow for 3 times, then pressurize and raise the temperature to carry out the esterification reaction, the reaction temperature is maintained at 230-260°C, and the pressure in the kettle reaches about 400kPa, then slowly release the pressure , when the esterification reaches more than 95%, the esterification reaction ends, at this time, the pressure in the kettle is below 20 kPa, and the temperature at the top of the tower is below 100 °C;

(2) After the esterification reaction is finished, close the valve of the process tower, add the stabilizer trimethyl phosphate from the feed hopper, vacuumize the feed hopper with nitrogen for three times, then open the valve of the feed hopper after feeding 150 kPa of nitrogen to pressurize the stabilizer into the kettle, and then slowly pump out the pressure in the kettle to -100 kPa, then fully open the vacuum valve, and carry out the polycondensation reaction under high vacuum, during which the temperature in the kettle is maintained between 290-300 ℃, and the reaction time is 180 minutes;

(3) After the polycondensation reaction is completed, the material is discharged, cooled, and pelletized to obtain a rigid polyester engineering plastic with a high melting point and a high glass transition temperature.

Example 2

A rigid polyester engineering plastic with a high melting point and a high glass transition temperature and a preparation method thereof, which are synthesized from raw materials including 1200 g of terephthalic acid, 500 g of ethylene glycol (8.06 mol), and 350 g of phenolphthalein (1.1 mol), antimony ethylene glycol 0.8g, trimethyl phosphate 2 g, antioxidant 1010 3 g.

The production method of the rigid polyester engineering plastic with high melting point and high glass transition temperature comprises the following steps:

(1) Weigh terephthalic acid, ethylene glycol, phenolphthalein, ethylene glycol antimony catalyst and antioxidant 1010 and mix them evenly, add them to a 5 L reaction kettle, stir for 30 minutes, then turn off the stirring, and turn on the vacuum system slowly Extract the oxygen in the kettle, then pass nitrogen to normal pressure, repeat the vacuum pumping and nitrogen ventilation for 3 times, then pressurize and raise the temperature to carry out the esterification reaction, the reaction temperature is maintained at 230-260°C, and the pressure in the kettle reaches about 400kPa, then slowly release the pressure , when the esterification reaches more than 95%, the esterification reaction ends, at this time, the pressure in the kettle is below 20 kPa, and the temperature at the top of the tower is below 100 °C;

(2) After the esterification reaction is finished, close the valve of the process tower, add the stabilizer trimethyl phosphate from the feed hopper, vacuumize the feed hopper with nitrogen for three times, then open the valve of the feed hopper after feeding 150 kPa of nitrogen to pressurize the stabilizer into the kettle, then slowly pump out the pressure inside the kettle to -100 kPa, then fully open the vacuum valve, and carry out the polycondensation reaction under high vacuum, during which the temperature in the kettle is maintained between 290-300 ℃, and the reaction time is 300 minutes;

(3) After the polycondensation reaction is completed, the material is discharged, cooled, and pelletized to obtain a rigid polyester engineering plastic with a high melting point and a high glass transition temperature.

Example 3

A rigid polyester engineering plastic with a high melting point and a high glass transition temperature and a preparation method thereof, which are synthesized from raw materials including 1200 g terephthalic acid, 600 g (9.67 mol) of ethylene glycol, and 100 g (0.31 mol) of phenolphthalein mol), ethylene glycol antimony 1.2 g, trimethyl phosphate 2 g, antioxidant 626 3 g.

The production method of the rigid polyester engineering plastic with high melting point and high glass transition temperature comprises the following steps:

(1) Weigh and mix terephthalic acid, ethylene glycol, phenolphthalein, ethylene glycol antimony catalyst and antioxidant 626 evenly, add them to a 5 L reactor, stir for 30 minutes, then turn off the stirring, and turn on the vacuum system slowly Extract the oxygen in the kettle, then pass nitrogen to normal pressure, repeat the vacuum pumping and nitrogen ventilation for 3 times, then pressurize and raise the temperature to carry out the esterification reaction, the reaction temperature is maintained at 230-260°C, and the pressure in the kettle reaches about 400kPa, then slowly release the pressure , when the esterification reaches more than 95%, the esterification reaction ends, at this time, the pressure in the kettle is below 20 kPa, and the temperature at the top of the tower is below 100 °C;

(2) After the esterification reaction is finished, close the valve of the process tower, add the stabilizer trimethyl phosphate from the feed hopper, vacuumize the feed hopper with nitrogen for three times, then open the valve of the feed hopper after feeding 150 kPa of nitrogen to pressurize the stabilizer into the kettle, and then slowly pump out the pressure in the kettle to -100 kPa, then fully open the vacuum valve, and carry out the polycondensation reaction under high vacuum, during which the temperature in the kettle is maintained between 290-300 ℃, and the reaction time is 240 minutes;

(3) After the polycondensation reaction is completed, the material is discharged, cooled, and pelletized to obtain a rigid polyester engineering plastic with a high melting point and a high glass transition temperature.

Example 4

A rigid polyester engineering plastic with a high melting point and a high glass transition temperature and a preparation method thereof, which are synthesized from raw materials comprising the following qualities: 1200 g terephthalic acid, 600 g (9.67 mol) of ethylene glycol, and 200 g (0.63 mol) of phenolphthalein mol), ethylene glycol antimony 1.2 g, trimethyl phosphate 2 g, antioxidant 168 3 g.

The production method of the rigid polyester engineering plastic with high melting point and high glass transition temperature comprises the following steps:

(1) Weigh and mix terephthalic acid, ethylene glycol, phenolphthalein, ethylene glycol antimony catalyst and antioxidant 168 evenly, add them to a 5 L reactor, stir for 30 minutes, then turn off the stirring, and turn on the vacuum system slowly Extract the oxygen in the kettle, then pass nitrogen to normal pressure, repeat the vacuum pumping and nitrogen ventilation for 3 times, then pressurize and raise the temperature to carry out the esterification reaction, the reaction temperature is maintained at 230-260°C, and the pressure in the kettle reaches about 400kPa, then slowly release the pressure , when the esterification reaches more than 95%, the esterification reaction ends, at this time, the pressure in the kettle is below 20 kPa, and the temperature at the top of the tower is below 100 °C;

(2) After the esterification reaction is finished, close the valve of the process tower, add the stabilizer trimethyl phosphate from the feed hopper, vacuumize the feed hopper with nitrogen for three times, then open the valve of the feed hopper after feeding 150 kPa of nitrogen to pressurize the stabilizer into the kettle, and then slowly pump out the pressure inside the kettle to -100 kPa, then fully open the vacuum valve, and carry out the polycondensation reaction under high vacuum, during which the temperature in the kettle is maintained between 290-300 ℃, and the reaction time is 280 minutes;

(3) After the polycondensation reaction is completed, the material is discharged, cooled, and pelletized to obtain a rigid polyester engineering plastic with a high melting point and a high glass transition temperature.

Example 5

A rigid polyester engineering plastic with a high melting point and a high glass transition temperature and a preparation method thereof, which are synthesized from raw materials including 1200 g of terephthalic acid, 600 g of ethylene glycol (9.67 mol), and 350 g of phenolphthalein (1.1 mol), ethylene glycol antimony 1.2g, trimethyl phosphate 2 g, antioxidant 168 3 g.

The production method of the rigid polyester engineering plastic with high melting point and high glass transition temperature comprises the following steps:

(1) Weigh and mix terephthalic acid, ethylene glycol, phenolphthalein, ethylene glycol antimony catalyst and antioxidant 168 evenly, add them to a 5 L reactor, stir for 30 minutes, then turn off the stirring, and turn on the vacuum system slowly Extract the oxygen in the kettle, then pass nitrogen to normal pressure, repeat the vacuum pumping and nitrogen ventilation for 3 times, then pressurize and raise the temperature to carry out the esterification reaction, the reaction temperature is maintained at 230-260°C, and the pressure in the kettle reaches about 400kPa, then slowly release the pressure , when the esterification reaches more than 95%, the esterification reaction ends, at this time, the pressure in the kettle is below 20 kPa, and the temperature at the top of the tower is below 100 °C;

(2) After the esterification reaction is finished, close the valve of the process tower, add the stabilizer trimethyl phosphate from the feed hopper, vacuumize the feed hopper with nitrogen for three times, then open the valve of the feed hopper after feeding 150 kPa of nitrogen to pressurize the stabilizer into the kettle, and then slowly pump out the pressure inside the kettle to -100 kPa, then fully open the vacuum valve, and carry out the polycondensation reaction under high vacuum, during which the temperature in the kettle is maintained between 290-300 ℃, and the reaction time is 280 minutes;

(3) After the polycondensation reaction is completed, the material is discharged, cooled, and pelletized to obtain a rigid polyester engineering plastic with a high melting point and a high glass transition temperature.

The performance tests of the rigid polyester engineering plastics with high melting point and high glass transition temperature obtained in Examples 1-5 are shown in the table below.

The polyester engineering plastic of the present invention greatly improves the glass transition temperature, melting point, thermal decomposition temperature, and aging resistance, can prolong the service life, and has high tensile strength, excellent dimensional stability, and excellent toughness , fatigue resistance, excellent environmental resistance, outstanding flame retardancy and low smoke generation.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still understand the foregoing embodiments The recorded technical solutions are modified, or some of the technical features are equivalently replaced. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (6)

1. a kind of high melting point, the rigid polyester engineering plastics of high glass transition temperature, it is characterized in that, described plastics is synthesized by the raw material that comprises following weight portion: Diformic acid monomer 1000-1200 parts, 400-700 parts of diol monomer, 100-350 parts of phenolphthalein, Catalyst 0.5-2 parts, Stabilizer 1-4 parts, Antioxidant 1-8 parts. 2. high melting point according to claim 1, the rigid polyester engineering plastics of high glass transition temperature, it is characterized in that, described diformic acid monomer is terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, bicarbonate One of phthalic acid; The diol monomer is one of ethylene glycol, propylene glycol, and 1,4-cyclohexanedimethanol; The catalyst is one of antimony series, titanium series and germanium series catalysts; The stabilizer is one or more of phosphoric acid esters and phosphite esters; The antioxidant is one or more of phenols, amines, phosphites, and sulfur-containing antioxidants. 3. The rigid polyester engineering plastic with high melting point and high glass transition temperature according to claim 1, wherein the molar number of the phenolphthalein is less than 50% of the molar number of the dibasic alcohol monomer. 4. The rigid polyester engineering plastic with high melting point and high glass transition temperature according to claim 1, characterized in that the glass transition temperature of the plastic is ≥90°C, the melting point is ≥250°C, and the intrinsic viscosity is ≥0.65 dL /g, thermal decomposition temperature ≥490°C. 5. the preparation method of the rigid polyester engineering plastics of high melting point, high glass transition temperature described in any one of claim 1-4, is characterized in that, comprises the steps: (1) Mix dicarboxylic acid monomer, diol monomer, phenolphthalein, catalyst and antioxidant evenly, add to the reaction kettle and stir, then heat for esterification reaction, when the esterification reaches more than 95%, the esterification The reaction is over; (2) After the esterification reaction is finished, add a stabilizer to the product obtained in step (1), and carry out polycondensation reaction under vacuum; (3) After the polycondensation reaction is completed, the material is discharged, cooled, and pelletized to obtain a rigid polyester engineering plastic with a high melting point and a high glass transition temperature. 6. The method for preparing rigid polyester engineering plastics with high melting point and high glass transition temperature according to claim 5, characterized in that, in the step (1), the stirring time is 30 min, and the temperature of the esterification reaction is 230-260°C; In the step (2), the polycondensation reaction is carried out at a relative vacuum pressure ≥ -100kPa, the reaction temperature is 290-300°C, and the reaction time is 180-360min.