检索规则说明:AND代表“并且”;OR代表“或者”;NOT代表“不包含”;(注意必须大写,运算符两边需空一格)
检 索 范 例 :范例一: (K=图书馆学 OR K=情报学) AND A=范并思 范例二:J=计算机应用与软件 AND (U=C++ OR U=Basic) NOT M=Visual
作 者:万小芳[1] 黄春柳[1] 李友明[1] 柴欣生[1] 胡会超[1]
机构地区:[1]华南理工大学制浆造纸工程国家重点实验室,广东广州510640
出 处:《华南理工大学学报(自然科学版)》2013年第7期75-80,93,共7页Journal of South China University of Technology(Natural Science Edition)
基 金:国家自然科学基金资助项目(20776055)
摘 要:采用阳离子细乳液聚合,以八甲基环四硅氧烷(D4)为原料、十二烷基苯磺酸(DBSA)为催化剂、乙烯基二甲基乙氧基硅烷(EDEV)为封端剂制备分子链端含双键的聚硅氧烷中间体,以进一步合成疏水性能更好的硅丙乳液.考察了聚合温度、DBSA用量、封端剂种类、EDEV用量及EDEV加入时间对D4单体转化率、产品粒径及其多分散指数(PDI)的影响.结果表明:聚合温度85℃、DBSA用量6%、EDEV用量1.0%、聚合反应开始后3h加入EDEV可得到粒径为95.3nm、PDI为0.123的稳定有机硅细乳液聚合产品,单体转化率达92.1%;FT-IR分析表明封端剂有效地参与了细乳液聚合反应;TEM测试表明聚合物粒子为纳米结构.文中还建立了主要工艺参数对D4阳离子细乳液聚合制备官能化聚硅氧烷的转化率影响的预测模型.In order to synthesize silicone-acrylate emulsion with stronger hydrophobicity, polydimethylsiloxane ended with vinyl terminal groups was synthesized via the cationic miniemulsion polymerization of octamethylcyclotetrasiloxane (D4 ) monomer, with dodeeytbenzene sulfonic acid (DBSA) as the catalyst and with ethenylethoxydimethyl silane (EDEV) as the blocking agent. Then, the effects of polymerization temperature, DBSA dosage, blocking agent type, EDEV dosage and EDEV addition time on the monomer conversion rate, the latex particle radius and the polydispersity index (PDI) were investigated. The results indicate that stable polymerization product of silicone miniemulsion, which is of a radius of 95.3 nm, a PDI of 0. 123 and a monomer conversion rate of 92.1% , can be obtained via the polymerization at 85 ~C , with a DBSA dosage of 6% , an EDEV dosage of 1.0% and an EDEV addition time of 3 h. FF-IR results show that the blocking agent effectively takes part in the miniemulsion polymeri- zation. TEM analysis indicates that the product is in a nano-strueture. Moreover, a model is proposed to predict the D4 conversion rate of functional polysiloxane varying with the main technological parameters.
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在链接到云南高校图书馆文献保障联盟下载...
云南高校图书馆联盟文献共享服务平台 版权所有©
您的IP:3.149.246.99