影响氟改性硅丙乳液聚合及其聚合物膜表面特性的因素

Influencing factors of emulsion polymerization of fluorine-modified silicon-acrylate and surface property of copolymer film

采用种子乳液聚合方法制备了阴、阳离子型氟改性硅丙乳液,用红外光谱对聚合物进行了表征,考察了聚合温度、氟改性单体和种子乳液的用量、乳化剂用量和pH值等因素对转化率和聚合物膜与水之间接触角的影响。结果表明,该聚合物中含有聚硅氧烷链段和CF2基团;聚合温度对转化率的影响较显著;在阳离子乳化体系中,当聚硅氧烷种子乳液、含氟丙烯酸酯单体和乳化剂的用量分别为10%、10%和1.1%时,转化率可以达到90%左右,接触角达到104°以上;随着体系pH值的逐渐增大,阳离子型氟改性硅丙乳液的Zeta电位明显降低,但阴离子型乳液的Zeta电位变化较小。

The cationic and anionic emulsions of fluorinemodified silicon-acrylate were prepared through seeding emulsion polymerization. The effects of polymerization temperature, the contents of fluorine and seeding latex, the emulsifier amount and pH value of polymerization system on polymerization conversion and the contact angle of produced copolymer film to water were examined. The results showed that the produced polymer had polydimethylsiloxane segment and CF2 group. The polymerization system was extremely sensitive to polymerization temperature. The conversion was about 90% and the contact angle was more than 104° in cationic emulsion system when mass fraction of seeding latex, mono-mer contained fluorine and emulsifier were 10%, 10% and 1.1% respectively. In addition, the effect of pH value on the Zeta potential of fluorine-modified silicone-acrylate emulsion in cationic emulsion system was rather different from that in anionic emulsion system. In cationic emulsion system, the Zeta potential reduced while pH value was enhanced, but in anionic emulsion system, the Zeta potential changed unnoticeablly.