A method for making 1-alkene/excess maleic anhydride polymers

摘要

Disclosed is a method of making a polymer containing more than 50 to about 95 mole percent, preferably 65 to 80 mole percent, of units derived from maleic anhydride and the balance units derived from at least one 1-alkene. Specifically, the present invention provides for a method for making a free radical addition polymer of maleic anhydride and at least one 1-alkene characterized by the steps of (A) mixing maleic anhydride with at least one 1-alkene selected from the group consisting of 1-alkenes having from 4 to 30+ carbon atoms in the presence of an effective amont of a thermally decomposable initiator to initiate the polymerization reaction at a temperature of from about 145 DEG C to 200 DEG C, preferably from about 160 DEG C to 200 DEG C, to form a reaction mixture wherein a major portion of the maleic anhydride and 1-alkene is proportionally added over a period of time at a rate which is substantially equal to the rate of reaction of the maleic anhydride and 1-alkene to form said reaction mixture and the molar ratio of maleic anhydride to total 1-alkene present is maintained at a ratio of more than 50:50 up to about 95:5 during the course of the reaction; and (B) thereafter maintaining the reaction mixture at a temperature of from about 145 DEG C to 200 DEG C, preferably from about 160 DEG C to 200 DEG C, until a polymer containing more than 50 mole percent up to about 95 mole percent of maleic anhydride is obtained. In an alternative embodiment, the method further comprises preparing a precharge of maleic anhydride and the 1-alkene selected in more than a 50:50 to about 95:5 molar ration, heating the precharge to 145 DEG C to 200 DEG C and thereafter mixing the remaining reactants into the precharge.