SU1505933A1 - 2-isopropyl-3-vinyl-5-phenylpyrrolidine as stabilizer of chloroprene rubber - Google Patents

Abstract

The invention relates to heterocyclic compounds, in particular 2-isopropyl-3-vinyl-5-phenylpyrrolidine, which can be used as a stabilizer for chloroprene rubber. The goal is to create more effective chloroprene rubber stabilizers. The synthesis is carried out by the reaction of isobutylidene benzylamine with butadiene in the presence of metallic sodium and neozone D in an environment of benzene or tetrahydrofuran at 70-80 ° C or at room temperature and a butadiene feed rate of 0.25 ml / min. After termination of the supply of butadiene, the mixture is heated for 2 hours. Yield 40-78%, bp.115-116 ° C, gross formula C ₁₅ N ₂₁ N. Tests show that the putative stabilizer exhibits antioxidant effect in concentrations (0 , 4-0.1 parts by weight) 10 times smaller than 3-isopropyl-1,4-diphenylpyrazolidine. 1 tab.

Description

The invention relates to a new chemical compound of the pyrrolidine series, namely, the 2-isopropyl-3-vinyl-5-phenylpyrrolidium of formula

g-n cn

sns

H, Sat N

n

as a stabilizer for chloroprene rubber.

The aim of the invention is to search in a series of pyrrolidine compounds having a higher stabilizing effect for chloroprene rubbers as compared to the coefficients used.

Example 1. In a four-necked flask equipped with a mechanical stirrer, a reflux condenser through which unreacted butadiene is taken into a cooled coil, 32.2 g (0.2 mol) of isobutylidene benzylamine, 50 ml benzene, 0.1 are placed into the coil. g metal

; l

about: l

GARDEN

3150

sodium and 0.1 g Iozoa D (for inhibiting butadiene polymerization). At iiai of the reaction mixture up to 70-80 ° C, 16.6 ml (0.2 mol) of butadiene are fed at a rate of 0.23 ml / min. After the addition of butadiene, the reaction mixture is heated for another 2 hours. After removal of the solvent by distillation, 17.2 g (40%) of 2-isoprolyl-3-vinyl-5-phenylpyrrolidine with a boiling point are obtained. 115-116 ° C (3mmHg), p 1.5330.

Found,%: C 83.58; H 9.82; N 6.59.

C, 5lUiN

Calculated,%: C 83.72; H 9.77;

N 6.51.

The experiment is carried out analogously to Example 1. The difference is that the reaction is carried out in tetrahydrofuran at room temperature. The self-heating temperature rises to 40-45 ° C. The yield of 2-isopropyl-3-vinyl-5-phenylpyrrolidine is 78%.

2-isopropyl-3-yynyl-5-phenylpyrrolidine was tested as a heat and light stabilizer for chloroprene rubber.

Stabilizing the additive serves as follows. Together with the monomer, 0.4-0.1 mph are fed into the polymerization mixture together with the monomer. (by monomer) 2-isopropyl-3-vinyl-5-phenylpyrrolidine. At a concentration of 0.5 wt.h. the polymerization process is slowed down; concentrations of a stabilizing additive are used at which the content of the remaining ingredient of the chloroprene emulsion polymerization is constant.

Investigation of the effectiveness of stabilization of chloroprene rubber 2- isoprop1-3-vinyl-5-phenylpyrrolidine is carried out using accelerated methods: UV irradiation of a PRK-4 mercury-quartz lamp and heat treatment at 100 ° C in air.

A comparison of the stabilizing effect of a compound of the proposed formula is carried out with an industrial stabilizer, agidol-2 and 3-isopropyl-1, 4-diphenylpyrazolidine.

The induction periods for the oxidation of chloroprene rubber stabilized by 2-isopropyl-3-vinyl-5-phenylpyrro are given in the table.

five

0

50

five

0

five

Sample without stabilizer: UV irradiation - 5 min, 100 ° С - 0.5 h.

Sample containing 0.4 wt.h. filed at the beginning and 1.6 mah. 2- isopr opil-3-vinyl-5-phenylpyrrolidine - at the end, during polymer deposition: UV irradiation - induction period 100 min, 100 ° С - 20 h.

Sample containing 2 May, h. Aguidol 2, applied during sedimentation: UV irradiation - 45 min, 100 ° C - 2.5 h.

Sample containing 2 ma.h. 3- isopropyl-1,4-diphenylpyrazolidine: UV irradiation - 8 min., - 6 h.

As can be seen from the data presented, 2-isopropyl-3-vinyl-5-phenylpyrrolidine, according to the data given at the beginning of the polymerization process, suppresses oxidative processes well both during light and thermal aging. When a stabilizer with a monomer is supplied, the antioxidant effect is achieved at concentrations of less than order.

Thus, the proposed compound is superior to agidol 2, used in the production of chloroprene rubber, as well as 2-isopropyl-1,4-diphenylpyrazolidine as a stabilizer of chloroprene rubber.

Claims (1)

Invention Formula 2-izopropyl-3-vinyl-5-phenylpyropoidine formula g-russ sng H s as a stabilizer for chloroprene rubber.