SU1135752A1 - Copolymer of decylmethycrylate with tetradecene as viscosity additive for lubrication oils - Google Patents

Abstract

Copolymer of decyl methacrylate with tetradecene of the general formula CH3(-CH2Hc-)n C-CH2CH2Hc-)n COOCyNH2 C HZS where n 24-54; m 6-12, mol. M1k.sy 8000-13000, as a viscosity additive to lubricating oils.

Description

1

The invention relates to new chemical compounds, more specifically to a copolymer of decyl methacrylate with tetradecene of the formula

SNz

f-CHr - )a -СИ2-СН-) 1

COOCioHgi

where Y is 24-54, Yn is 6-12, molecular weight is 8000-13000, which can be used as a viscosity additive to lubricating oils.

The specified compound and its properties have not been described in the literature.

A copolymer of alkyl methacrylate with acrylonitrile is known, which is used as a viscosity additive for 1C lubricating oils, possessing high resistance to thermal destruction l.

However, the specified copolymer does not have depressant properties, and in terms of resistance to thermal destruction it is significantly inferior to the proposed copolymer. Thus, if we compare the copolymer of decyl methacrylate with tetradecene and alkyl methacrylates with acrylonitrile of equal molecular weight (about 8000) in terms of resistance to thermal destruction, then the drop in viscosity during thermal destruction is 4.5 and 7%, respectively (Table 2).

The closest of the polymer viscosity additives to lubricating oils to the proposed copolymer are polymethacrylates, which, in addition, improve the low-temperature properties of lubricating oils 2 .

However, like all viscosity additives, polymethacrylates have low resistance to thermal degradation in oils.

The aim of the invention is to create a viscosity additive with increased resistance to thermal destruction of polymethacrylate.

The set goal is achieved by a new chemical structure of the general formula

CH3 - )p (- H2-CH-)l1

COOCjgHjl

357522

where p 24-54 m 6-12 mol. mass 8000-13000.

The copolymer was obtained by copolymerization of decyl methacrylate with tetradecene at 75-80 C in the presence of

benzoyl peroxide taken as a polymerization initiator, followed by isolation of the target product using known methods. 10 The reaction is carried out for 3-4 hours. The yield of the copolymer is 70-96%.

The structure and composition of the copolymers were established by IR, PMR spectroscopy and elemental analysis (based on carbon content).

When determining the content of tetradecene units in the copolymer, the integral intensity of the signal from the proton of the CI group 0 (chemical shift 1.53 ppm) was used.

Example 1. To a mixture of 90 g (0.4 g-mol) of decyl methacrylate and 10 g (0.05 g-mol) of tetradecene is added 1 g of benzoyl peroxide and stirred at 75-80 C for 4 hours. After completion of the copolymerization reaction, the mixture is subjected to vacuum to remove traces of unreacted monomers. Yield - 96% of the mixture of monomers, molecular weight 13000. Number of decyl methacrylate units - 54, tetradecene 6.

Example 2. 1 g of benzoyl peroxide is added to a mixture of 75 g (0.33 g-mol) of decyl methacrylate and 25 g (0.13 g-mol) of tetradecene and stirred at 75-80 C for 4 hours. Then processed as in Example 1. The yield of the copolymer is 88%, the molecular weight is 10700. The number of decyl methacrylate units is 35, tetradecene - 10.

Example 3. To a mixture of 60 g (0.26 g-mol) of decyl methacrylate and 40 g (0.21 g-mol) of tetradecene, 1 g of benzoyl peroxide is added and stirred at 75-80 0 for 4 hours. Then processed as in Example 1. The yield of the copolymer is 70%, the molecular weight is 8000. The number of decyl methacrylate units is 24, tetradecene - 12.

Decyl methacrylate and tetradecene copolymers are highly viscous rubber-like, slightly yellowish-colored substances that are readily soluble in benzene, aliphatic hydrocarbons and their halogen derivatives, and lubricating oils. The characteristics of the synthesized copolymers are presented in Table 1. As can be seen from the data in Table 1, an increase in the tetradecene content in the monomer mixture to 40 wt.% leads to a decrease in the yield and a decrease in the molecular weight of the copolymers, which is impractical. Therefore, the optimal concentration of tetradecene in the monomer mixture can be considered 10-30 wt.%. The obtained BS copolymers are studied as a viscosity additive to lubricating oils, for which their thermal destruction by heating 5% solutions in turbine oil is determined. The results of thermal destruction of decyl methacrylate with tetradecene copolymers are presented in Table 2. For comparison, the results of thermal destruction of decyl methacrylate homopolymer and industrial viscosity additive polyalkyl methacrylate, which is taken as a basic object for comparison, are given. As can be seen from the data in Table 2, an increase in the content of tetradecene in the copolymer composition to 26.7% leads to an increase in the stability of the copolymer (a drop in the viscosity of the thickened oil during destruction decreases from 11.5 to 4.6%). A further increase in the content of tetradecene (up to 34.9%) does not lead to an increase in stability. Thus, increasing the amount of tetradecene units in the copolymer composition by 25% is considered inappropriate. The synthesized copolymers are much superior to polydecyl acrylate and the base material in terms of resistance to thermal degradation. For example, the viscosity drop of the copolymer and the specified polymer compounds of equal molecular weight (13000) is 11.5; 17.9 and 17.8, respectively. Another indicator of viscosity additives is their effect on the viscosity-temperature properties of low-viscosity lubricating oils. Table 3 presents the results of the effect of the synthesized copolymers on the viscosity-temperature properties of I-12A oil. As can be seen from the data in Table 3, at the same molecular weight (10000) with an increase in the copolymer concentration from 0.5 to 1%, the pour point of the thickened oil decreases from -34 to -38°C. A further increase in the copolymer concentration does not lead to a decrease in the pour point of I-12A oil. With an increase in the content of tetradecene units in the copolymer from 8.1 to 18.3%, the pour point of the oil at the same concentration of copolymers (1%) decreases from -34 to -38°C. A further increase in the content of tetradecene in the copolymer does not lead to a positive effect. Thus, by copolymerization of decyl methacrylate with tetradecene it is possible to obtain a viscosity additive possessing not only high resistance to thermal destruction, but also depressant properties, which are not possessed by decyl methacrylate homopolymer (without tetradecene units) and industrial polymethacrylate based on esters with alcohol radicals. This makes it possible to use the copolymer of decyl methacrylate with tetradecene as an effective viscosity and depressant additive to petroleum lubricating oils. - On the other hand, copolymerization of methacrylic ether with olefin makes it possible to replace part of the expensive ether with olefin, which has potential resources; this will ensure the cost-effectiveness of the proposed viscosity additive.

Table 1

Characteristics of the copolymer

.«..«Contents of tetrademol. mass

Polydecyl methacrylate 8.9

18.3

26.7

34.9 Zolimethacrylate (industrial)

Table 2

Decrease in viscosity of 5% solution as a result of destruction, %

17.8

11.5

9.5

4.6

5 17.9

Table 3

8

1135752 Continuation of table 3