无皂硅丙乳液的合成及其在建筑涂料中的应用

Synthesis of Emulsifier-free Silicone-acrylic Emulsion and its Application in Architectural Coating

以甲基丙烯酸甲酯（MMA）、甲基丙烯酸（MAA）、乙烯基三甲氧基硅烷（YDH-171）、四甲基四乙烯基环硅氧烷（DV4）、烯丙基羟乙基醚（AOE）为原料,K2S2O8-Na2SO3为氧化还原引发体系,实施自乳化、开环同步进行的自由基无皂乳液聚合,合成了无皂硅丙乳液。通过L9（3）4正交实验优化的单体配比是：当体系p H值为4.5~5、K2S2O8与Na2SO3的质量比为2∶1且用量为单体总质量的0.5%时,MAA、AOE、YDH、DV4、MMA的质量比为8∶9∶4∶20∶59,此时聚合反应的凝胶率0.18%。红外光谱证实,DV4已开环且所有单体均已参与共聚反应;热重分析表明,无皂硅丙乳液的热稳定性好,最大热分解温度为449℃;粒度和透射电镜分析表明,乳胶粒平均粒径为158 nm,粒径分布窄（PDI=0.031,Zeta=-53.9 m V）,具有单分散性;常规性能检测表明,乳液的各项指标均达到国标要求。将硅丙乳液与金红石型钛白粉及各种助剂混合,配成建筑内墙涂料,其涂层的主要性能指标达到或超过国家标准。

The emulsifier-free silicone-acrylic emulsion was prepared by tetravinyl tetramethylcyclotetrasiloxane,vinyltrimethoxysilane,methyl methacrylate,methacrylate,2-allyloxyethanol（ AOE）,and K2S2O8-Na2SO3 as the redox initiation system. Thus the emulsifier-free silicone-acrylic emulsion was synthesized by emulsifier-free emulsion polymerization,with copolymer of MMA and MAA（ sodium） and AOE used as the emulsifiers. The optimum formulation found by L9（ 3）4orthogonal test was that at a mass ratio of MAA∶ AOE∶YDH∶ DV4∶ MMA = 8∶ 9∶ 4∶ 20∶ 59 with p H = 4. 5 ~ 5,K2S2O8∶ Na2SO3= 2∶ 1 with 0. 5% of the total monomers,the gel ratio was 0. 18%. FT-IR results show that DV4 is ring-opened and all the monomers participated in the copolymerization. Thermogravimetric analysis results show that the thermal stability of the emulsion is excellent and the maximum thermal decomposition temperature is 449℃. TEM and SEM shows that the average particle size of the emulsion is 158 nm,PDI = 0. 031,Zeta =- 53. 9 m V,with a narrow particle size distribution.Routine performance test results show that the key performance indicators,such as the freeze-thaw stability,dilution stability,alkali resistance,low temperature resistance,scrub resistance,meet or exceed the national standards. SEM analysis shows that the coating is delicate with smooth hand feel.