新型硅-丙核/壳乳液的制备与表征

以对甲苯磺酸(PTSA)为催化剂,十二烷基苯磺酸钠(DBSA-Na)和OP-10为复合乳化剂,选用八甲基环四硅氧烷(D4)、四甲基四乙烯基环四硅氧烷(Vi-D4)作为有机硅单体,通过乳液聚合工艺制备硅油中间体,然后将其与丙烯酸酯类共聚,通过对工艺方法、配方的调整得到了性能优良的硅-丙乳液。探讨了乳化剂加入量、种子乳液量、乙烯基硅含量(Vi-D4用量)、活性物含量等因素对硅-丙乳液转化率和接枝率以及乳胶粒形貌和乳液粒径分布的影响。结果表明,乳化剂质量分数0.8%,种子乳液质量分数30%,V(D4)∶V(Vi-D4)=4∶1,活性物质量分数30%时得到了转化率和接枝率高的硅-丙乳液。电镜照片显示,粒子呈明显的核壳结构。粒径分布图显示,乳液粒径分布较窄,平均粒径在100 nm左右。

Preparation and Characterization of New Core/Shell Silicon-acralyte Latex

In this work,the seed-emulsion was prepared using the octamethyl cyclotetrasiloxane(D4) and tetramethyl tetravinyl cyclotetrasiloxane(ViD4) as the main monomers,the sodium dodecyl benzene sulphate(Na-DBSA) and OP-10 as the composite emulsifier and the p-toluene sulfonic acid as the catalyst.Then,the seed-emulsion was respectively copolymerized with many kinds of acrylates to form the excellent silicon-acralyte emulsions.The effects of the dosage of emulsifier,seed-emulsion,Vi-D4 and monomer on conversion and grafted efficiency were discussed.Moreover,the structure,morphology and particle size distribution of emulsions were characterized.The results showed that when the dosage of emulsifier was at 0.8%,dosage of seed-emulsion at 30%,dosage of monomer at 30% and V(D4)∶V(Vi-D4) at 4∶1,silicon-acralyte latex with higher inverted efficiency and grafted efficiency was obtained.The result of TEM indicated the distinct core/shell structure was observed;particle size distribution showed the size dispersion of latex was narrow and the mean diameter was about 100 nm.