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THE ACCELERATING EFFECT OF ADDITIVES ON RADIATION-INDUCED GRAFT POLYMERIZATION. Final Report

Technical Report ·
OSTI ID:4794644

It was previously observed that the rates of various radiation-induced graft polymerizations were substantially increased by dilution of the monomers with certain solvents. These large rate increases were shown to be a general feature of graft polymerization since they occurred in a wide variety of graft polymerization systems. Monomers studied were styrene, methyl acrylate, and t- butylaminoethyl methacrylate; polymers included polyethylene, polypropylene, polyvinyl chloride, Teflon, and nylon. Am analysis of the kinetics of these irradiation-induced graft polymerizations was made in order to elucidate the mechanism of the solvent acceleration. The accelerations in the rates of graft polymerization were demonstrated to be due to two mechanisms. One is the incursion of a Trommsdorff effect due to the insolubilization of the growing graft polymer chains in the solvent-monomer medium. The other mechanism is the enhancement in the degree of accessibility of monomer to grafting sites within the polymer brought about by the greater ability of the solvent additive to swell the base polymer. The former mechanism is mainly responsible for the effects observed in the grafting of polyethylene, polypropylene, polyvinyl chloride and Teflon, while the latter mechanism is operative in the grafting of nylon. The commercial significance of these results is that it opens up the possibility of making radiation-induced graft polymerization a practical as well as useful process due to the lower costs brought about by the use of this technique. It allows the synthesis of certain copolymers, such as those of nylon, which could not be made by standard copolymerization techniques. ln addition, this technique extends the applicability of graft polymerization to radiation sensitive polymers such as polypropylene, polyvinyl chloride, polymethacrylates, and Teflon. Radiation-induced grafting via the technique of irradiation of resin-monomer mixtures was investigated. Monomer and polymer were mixed above the melt point of the latter and some of the properties of the irradiated blends examined. Two specific monomer-polymer systems were studied with the following results: irradiated polyethylene-vinyl stearate mixtures showed increased plasticization, and irradiated blends of polyethylene wtth diallyl phosphite and triallyl phosphate show improved temperature stability. (auth)

Research Organization:
Radiation Applications Inc., Long Island City, N.Y.
NSA Number:
NSA-16-014773
OSTI ID:
4794644
Report Number(s):
RAI-301
Country of Publication:
United States
Language:
English