| abstract |
What is described herein is a process for making a copolymer of high specific viscosity by polymerization of maleic anhydride and a C1-C4 alkyl vinyl ether monomer. The invention involves polymerizing said monomers to form a slurry of said copolymer in excess alkyl vinyl ether and toluene and is characterized by the steps of: (a) precharging a reactor with C1-C4 alkyl vinyl ether as solvent at a reaction temperature, (b) feeding a mixture of maleic anhydride and a C1-C4 alkyl vinyl ether in substantially stoichiometric amounts, preferably with a slight excess of the alkyl vinyl there, and at a selected rate, into said precharged reactor, and (c) simultaneously feeding a predetermined mixture of toluene and a polymerization initiator continuously over substantially the entire period of polymerization. |