REDUCTION OF POLYMER SCALE FORMATION DURING PVC MANUFACTURE

摘要

REDUCTION OF POLYMER SCALE FORMATIONDURING PVC MANUFACTUREAbstractUse of a small amount of an ammonium or an alkalimetal borate as a buffer in the suspension polymerization ofPVC to thereby control the pH between about 7.5 and 10,reducesthe amount of polymer scale which forms on the inner walls ofthe reactor. When initiators having a 10 hour half-life at atemperature below about 60°C, such as diisopropyl peroxydi-carbonate (IPP) and t-butyl perpivalate (TBP), are used furtherreactor cleanliness can be achieved by using them in a solventcomprising a C5-C12 straight or branched hydrocarbon, such ashexane or heptane.