Free-Radical Copolymerization Of α-Pinene

So far, there have been few reports about the free-radical copolymerizationofα-pinene, especially its free-radical copolymerization with vinyl acetate. Thefollowing aspects were studied in this paper:1.α-P and maleic anhydride (MA) were free-radically copolymerized withtert-butyl hydroperoxide as initiator to obtain terpene-maleic resins, whosesoftening points are in the range of 71.5～98℃. The product was identified tobe the copolymer ofα-P and MA by IR, element analysis, saponification valueand other analytical methods. Softening point of the product is significantlyhigher than that of the product (64℃) without initiator. Monomer ratio, reactiontime and other influncing factors in the process of copolymerization wereinvestigated. Q and e value ofα-P were calculated to be Q=0.06, e=-0.07 withthe date of other researchers, and the reactivity ratio ofα-P and MA werecalculated to be r₁=0.23 and r₂=0.019 with the Q and e value ofα-p and MA.Whereas element analysis result of the copolymer showed that the ratio ofconstruction units ofα-P and MA in the copolymer was ca. 1:1, which iscoincident with the reactivity ratio calculated from the Q-e value.2. Pale yellow to yellow solid, whose softening points are in the range of42～88℃, were obtained by free-radical copolymerization ofα-P and vinylacetate (VAc) with azobisisbutyronitrile as initiator. The product, whose molecular weight was in the range of 4000～7200, was identified to be thecopolymer of the both by IR, gel permeation chromatography (GPC), estergroup determination and other analytical methods. Influncing factors such asmonomer ratio, initiator concentration e. t. in the process of copolymerizationwere investigated; and reactivity ratio of the both monomers are r₁=2.33 and r₂=0.41, which were calculated with Q and e value ofα-P and VAc.3. When preparing white glue (polyvinyl acetate emulsion) of low solidcontent, addingα-P in small amounts (＜2% of the total mass of the white glue)to copolymerize with VAc can produce white glue whose apparent viscosity areobviously enhanced compared to the white glue without addingα-pinene in thesame preparing conditions, soα-P has the possibility of actual application in thisaspect.4.α-P and methyl methacrylate were free-radically copolymerized withbenzoyl peroxide as initiator to obtain white solid copolymer after speration ofthe monomers unreacted. The copolymer is easy to thermal decomposition.Influncing factors such as monomer ratio, reaction time in the process ofcopolymerization were investigated.