羧基聚醚共改性三硅氧烷的合成及其性能研究

实验以1,1,1,3,5,5,5-七甲基三硅氧烷(MD~HM)和端烯丙基聚氧乙烯聚氧丙烯醚(APPE)为原料,在氯铂酸催化下,经硅氢加成反应先制得聚醚三硅氧烷(PETS),再将PETS与氯乙酸(CA)进行缩合反应合成一种羧基聚醚共改性三硅氧烷(CPETS)。以IR对CPETS的结构进行了表征,并对CPETS的界面性能及在农药中的应用性能进行了测定。实验结果表明:氯铂酸用量(以铂计)占总单体质量分数4×10~(-5)、MD~HM和APPE按n(Si-H):n(C=C)=1.0:1.1、反应温度80～90℃、反应时间2～4 h,得浅褐色透明液体PETS;再按n(PETS):n(CA)=1.0:1.05、反应温度65～80℃、反应时间3～4 h,减压脱低沸物30 min后,得无色至微黄色透明液体CPETS。CPETS具有优良的表面活性,其临界胶束浓度(cmc)为1.6 g/L,临界胶束浓度时的表面张力(γ_(cmc))为25.2 mN/m。在41%草甘膦异丙胺盐水剂1 000倍稀释液中添加质量分数为0.10%的CPETS后,可使该农药稀释液的γ_(cmc)由55.20 mN/m降至26.96 mN/m;接触野菠菜的瞬间接触角由68.0°降低至46.5°,30 s时的接触角由56.0°降低至32.0°。

SYNTHESIS AND PROPERTIES OF CARBOXYL AND POLYETHER CO-MODIFIED TRISILOXANE

A new kind of carboxyl and polyether co-modified trisiloxane(CPETS) was synthesized by the condensation reaction of polyether substituted trisiloxane(PETS) with chloroacetic acid(CA). PETS was prepared by hydrosilylation from 1,1,1,3,5,5,5-heptamethyltrisiloxane(MD~HM) and allyl polyoxyethylenepolyoxypropylene ether(APPE) in the presence of chloroplatinic acid catalyst.The chemical structure of CPETS was characterized by IR.The interfacial properties of CPETS were measured,and its application was investigat...