STUDY OF PROPERTIES OF ISOPRENE OLIGOMERS OBTAINED BY MICROWAVE IRRADIATION OF SKI-3 RUBBER

Abstract

The present article proposes a method for production of low molecular weight rubber in microwave irradiation field. Isoprene rubber SKI-3 (10% solution in toluene) was used as the initial reactant. The effect of MWI power change (144 W, 450 W, 675 W, 900 W) on the degree of destruction was studied. The degree of destruction was measured based on the change in viscosity average molecular weight. The findings of the experiment data analysis indicate that the destruction process occurs in correspondence with the following dependency: the increase in the microwave irradiation power raises the destruction degree. At the same time, a decrease in molecular weight was observed. Furthermore, it was found that the use of phospholipids as modifiers also affects the destruction process. The increase in phospholipids content in toluene-SKI-3 system reduces the degree of polyisoprene destruction regardless of the microwave irradiation power. It is demonstrated by the fact that rubber molecular weight is subject to a lower decrease in systems with higher phospholipids content. Phospholipids perform two functions. Firstly, they act as a stabilizer that inhibits the rubber destruction process. Secondly, varying their content allows controlling the destruction degree and obtaining oligomers with predetermined molecular weight. The obtained oligomers were used as SKI-3 isoprene rubber modifiers. It is observed that that the introduction of oligomers into rubber mixtures in the amount of 7 and 10 parts by weight per 100 parts by weight of rubber increases its cohesive strength. Furthermore, vulcanizates containing oligomers are characterized by improved physical and mechanical properties.