Preparation Of Styrene-maleic Anhydride-acrylate Terpolymer Particles Via Self-stablized Precipitation Polymerization

Styrene-maleic anhydride copolymer(SMA)is a high-performance polymer material.However,the presence of anhydride segements in the copolymer results in a high processing temperature and poor water resistance.In order to reduce the glass transition temperature(Tg)of SMA,styrene(St)-maleic anhydride(MAH)-butyl acrylate terpolymer(SMB)was synthesized by self-stabilized precipitation polymerization using butyl acrylate(BA)as the third monomer.The influence of reaction conditions,includind type of solvent,monomer feed ratio and type of the third monomer,on the morphology and Tg of the obtained SMB was studied.The main work is as follows:1.SMB terpolymer particles were prepared via self-stable precipitation polymerization with BA as the third monomer.The composition of the product was characterized by IR and NMR.The influences of reaction medium on the size and morphology of the as-prepared polymer particles were investigated in detail.Based on the experimental results,xylene and isoamyl acetate were chosen as the solvent.2.With isoamyl acetate as solvent,the effect of monomer feed ratio on the morphology and Tg of SMB was studied.The experimental results indicated that the content of BA in the polymer product increased gradually and their Tg decreased significantly with increasing monomer feed ratio of BA.The addition of n-heptane into the reaction system can effectively increase the particle yield and decrease the Tg of SMB.The size and yield of the SMB microspheres increased with increasing monomer concentration.When n-heptane is 20 wt%relative to isoamyl acetate and St:MAH:BA=5:2:3,the Tg of SMB is 167℃,which is 39℃ lower than that of SMA.3.The effect of monomer feed ratio on the microspherical morphology and Tg of SMB was studied with xylene as a solvent.The experimental results indicated that the content of BA in the polymer product increased and the Tg decreased significantly as the ratio of BA in the monomer feed increased.When n-heptane is 20 wt%and St:MAH:BA=5:2.5:2.5,the Tg of SMB is 166℃.4.The effect of type of the third monomer on the morphology and Tg of the obtained microspheres were investigated under the same reaction conditions.When methyl acrylate(MA)was used as the third monomer,the morphology of the obtained microspheres was the best and the particle yield was the highest.The Tg of the microspheres was the lowest with BA was the third monomer.With 2-ethylhexyl acrylate(2-EHA)as the third monomer,the yield of microspheres was the lowest,and the adhesion between particles was the most serious.In order to improve the practical application value of carbon 8 mixture(C8),C8 was used instead of St to react with other two monomers to prepare C8-MAH-BA terpolymers particles.The main works is as follows:5.C8-MAH-BA terpolymers particles were synthesized by self-stabilized precipitation polymerization with BA as the third monomer.The composition of the product was characterized by IR.6.With xylene as solvent,the effect of monomer feed ratio and reaction time on the morphology and Tg of Cg-MAH-BA terpolymers particles was studied.The experimental results indicated that their Tg decreased significantly with increasing monomer feed ratio of BA.The addition of n-heptane to isoamyl acetate can decrease the Tg of C8-MAH-BA terpolymers particles.When n-heptane is 20 wt%relative to xylene and C8:MAH:BA=5:1:4,the Tg of C8-MAH-BA terpolymers particles is 167℃.