聚丙烯酸酯原位乳液聚合包覆纳米硅溶胶的研究

Study on Polyacrylate Encapsulated Nano-SiO_2 Sol By In-suit Emulsion Polymerization

首先 ,用水溶性聚合物羟丙基甲基纤维素 (HPMC)包覆纳米二氧化硅溶胶 (SiO2 ) ;然后 ,通过原位乳液聚合法制成以SiO2 为核 ,聚丙烯酸酯 (ACR)为壳的复合物。实验表明 ,当包覆温度为 6 0℃、且nHPMC∶nSiO2 等于 1∶1 6时 ,HPMC -SiO2 /ACR复合乳液的稳定性较好 ;ACR的转化率及反应速率随SiO2用量的增加而下降。用HPMC -SiO2 质量分数为 3%～ 2 0 %的HPMC -SiO2 /ACR复合物改性PVC时 ,拉伸强度随HPMC -SiO2 质量分数的增加而增大 ,当HPMC -SiO2 质量分数达到 2 0 %后开始下降 ;而断裂伸长率和冲击强度在HPMC -SiO2 质量分数为 5

s:Firstly nano-SiO 2 sol particles was pre-encapsulated with water-soluble polymer hydroxypropylemthylcellulose(HPMC), then a composite which consisted of nano-SiO 2 sol particles as core and polyacrylate as shell was synthesized by in-suit emulsion polymerization,. The result showed that the emulsion of HPMC-SiO 2/ACR compound had excellent stability, when the nano-SiO 2 sol particles was encapsulated with HPMC at 60 ℃ and the ratio of n HPMC and n SiO 2 was 1∶16;the conversation and reacting rate of ACR decreased with the increase of the content of HPMC-SiO 2 sol; the tensile strength of HPMC-SiO 2/ACR/PVC composite increased with the increase of the mass faction of HPMC-SiO 2 sol as the content of HPMC-SiO 2 in ACR compound was 3 %～20 %, but decreased as the content of HPMC-SiO 2 in ACR was at 20%; the elongation rate at rupture and the impact strength were the largest as the content of HPMC-SiO 2 in ACR was at 5 % .