Polymerization of styrene in an electrodeless glow discharge

Abstract

Abstract The polymerization (polymer deposition) rate of styrene in an electrodeless glow discharge from styrene vapor and a mixture of styrene vapor and gas (H 2 , He, A, and N 2 ) was investigated. The rate of polymerization, R , was found to be independent of the discharge power. The rate of polymerization of the pure monomer was found to be proportional to the square of monomer pressure p M . The addition of gas increased the rate of polymerization depending upon the partial pressure of the gas, p x , and R can be generally expressed by R = a [ p M ] 2 {1 + b [ p x ]}. The value of b is dependent of the type of gas and follows the order of N 2 , > A > He > H 2 . The distribution of polymer deposition was found to be nearly independent of the partial pressure of the gas and of the discharge power with N 2 and H 2 as plasma gas; however, with He and A, the distribution is highly dependent on the partial pressure of the gas and on the discharge power. The study strongly suggests that polymerization occurs in the vapor phase and that the growing polymer radicals deposit on the surface of the discharge vessel, yielding highly crosslinked polymer deposition.