Effect of copolymers of decyl methacrylate with dicyclopentadiene on service characteristics of low-viscosity oils

Abstract

The viscosity-temperature characteristics of lube oils are among their most important properties in terms of service. Oils with high viscosity index and good low-temperature pumpability are formulated by blending base stocks with poly(alkyl methacrylates). However, these polymers are highly susceptible to thermal breakdown in the lube oil, with a consequent drop in oil viscosity below the allowable level under service conditions. In the development of polymers with better resistance to breakdown, we have synthesized a copolymer of decyl methacrylate with dlcyclopentadiene (DCP) [I]. This copolymer can be considered to be a modified poly(alkyl methacrylate), and it is better than the homopolymer in terms of breakdown resistance. The copolymerlzation of decyl methacrylate with DCP was performed in the presence of a radical polymerization initiator, in toluene medium. Copolymers were obtained with molecular weights of 8000 to 15,000, containing 5% to 30% DCP units; The r yields ranged from 70% to 98%.