INTERMITTENT PROCESS FOR PRODUCING POLYISOBUTYLENE TELECELICS

摘要

Monomer is added in discrete steps during the prodn. of poly-chloroisobutylene telehelics. The process is controlled by continuous monitoring of dielectric constant, conductivity and temp. During prepn. a solvent is placed in a directly cooled reactor of 0.1-5 cu.dm. volume. Initially 0.005-0.25 cu.dm. of co-initiator (a Lewis acid) is introduced in the solvent, followed by the initiator in soln. cationisation is started by a small portion of the monomer. Following this ion generating step, chain propagation is achieved by gradual addn. of all the monomer, in a liq. state, in discrete volumes (1/3-1/20 portions). Addn. of a new portion takes place when binary ionogenic equilibria are reached after a previous addn. When all monomer is added sufficient chain terminating agent (alcohol) is added to the reaction mix to ensure that the dielectric constant of the system reaches its minimum value