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室温交联单组份丙烯酸酯乳液的制备与性能研究
Preparation and Properties of Ambient Curing One-component Acrylate Latex
【作者】 黄冠平;
【导师】 王炼石;
【作者基本信息】 华南理工大学 , 材料学, 2011, 硕士
【摘要】 单组份室温交联技术具有操作简单、成本较低﹑能耗小等优点,是改性热塑性树脂的重要手段,也是目前水性涂料研究的重点之一。本文通过粒子设计,优化乳液聚合工艺,合成了乙酰乙酰基/胺基和有机硅改性两种体系的室温交联核壳型丙烯酸酯乳液,用其制备了室温交联丙烯酸酯乳液涂料;以室温交联丙烯酸酯树脂为成膜基料,制备了水性室温交联金属闪光涂料。采用预乳化半连续乳液聚合,通过甲基丙烯酸乙酰乙酰氧基乙酯(AAEM)与丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)、苯乙烯(St)、甲基丙烯酸异冰片酯(IBOMA)、丙烯酰胺(AM)共聚,合成了核壳型丙烯酸酯乳液。研究了乳化剂用量、核壳间乳化剂用量比例、引发剂用量、单体配比、固化剂用量对乳液聚合和漆膜性能的影响,并用傅里叶红外光谱(FTIR)、透射电镜(TEM)、热重分析(TGA)、激光粒度仪等现代分析手段进行了表征。结果表明当反应性乳化剂用量为3%,核、壳乳化剂用量之比为40/60,所合成的乳液成膜性良好,乳胶粒子粒径为100nm左右,且粒径分布窄;当AM、IBOMA、AAEM的用量分别为2%、8%和5%,固化剂γ-氨丙基三乙氧基硅烷(KH550)用量与AAEM等物质的量时,漆膜的综合性能较好,耐水性达到了37小时。通过物理共混法和化学共聚法对丙烯酸酯乳液进行有机硅改性,对比了两种方法的改性效果。结果表明,采用纳米硅溶胶对丙烯酸酯乳液进行共混改性,乳液流变性能有所改善,流挂现象显著减少,漆膜的丰满度提高,当硅溶胶与丙烯酸酯乳液用量之比为8:100时,乳液稳定性和漆膜的综合性能较好;采用不同的有机硅单体,乙烯基三乙氧基硅烷(A151)和γ-甲基丙烯酰氧丙基三甲氧基硅烷(A174)共聚改性核壳型丙烯酸酯乳液,乳胶膜的玻璃化转变温度在17℃左右,乳液成膜性良好,A174对丙烯酸酯乳液性能的改性效果明显,当A174用量为10%时,漆膜的综合性能最好,耐水性达到110小时,吸水率为4.5%。用有机硅改性的核壳型丙烯酸酯共聚乳液、水性铝粉和水性涂料助剂制备了金属闪光涂料,分析了流变控制剂醋酸丁酸纤维素(CAB)对金属闪光涂料贮存稳定性和漆膜光泽度的影响,发现当其用量为1.5%,铝粉颜料用量为20%时,金属闪光涂料的贮存稳定性较好,漆膜光泽度较高,综合性能较好。
【Abstract】 One-component ambient cross-linkable technique which having the advantage of simple operation,lower cost and less energy comsumption is the important method of modifying thermoplastic resins and the reserch foucs of waterborne coating.Two kinds of ambient crosslinkable core-shell acrylic latex,containing acetoacetate groups and organic siliconer,respectively,were synthesized by particle design and optimizing emulsion polymerization process.Metalic coating was studied,which using ambient crosslinkable latex as film forming matrix.The core-shell acrylic latex was synthesized by pre-emulsificational semi continuous emulsion polymerization of acetoacetoxyethyl methacrylate(AAEM), butyl acrylate(BA), methacrylate (MMA), styrene(St),isobornyl methacrylate(IBOMA) and acrylamide(AM) with reactive emulsifier.The effect of emulsifier dosage,mass ratio of emulsifier in core and shell,initiator dosage,monomers proportion and curing agent content on copolymerization behavior and properties of latex film were studied.The latex and its film were characterized by FTIR,TEM,TGA and laser scattering.The results showed that the latex exhibited excellent film forming performance,the latex particles had number-average diameter of 100nm and narrowdispersed polydispersity.The latex film exhibited better mechanical properties and water resistance of 37 hours when the content of emulsifier was 3%,the mass ratio of emulsifier in core and shell was 40/60 respectively,the content of AM,IBOMA,AAEM were respectively 2%,8%,5%,the amount substance ratio of 3-triethoxysilylpropylamine(KH550) and AAEM was 1:1Silicone modified acrylic latexs were prepared by blend and copolymerization,these two modified methods were compared.The results showed that blending modified acrylic latex with nanosilicasol could improve the rheology of latex,reduce sagging and also increase the fullness of film.The stability of emulsion and mechanical properties of film were better when the mass ratio of silicasol and acrylic emulsion was 8:100.Silicone modified core-shell acrylic emulsion was synthesized by copolymerization of acrylic monomers with triethoxylsilane (A151) and 3-methacryloxypropyltrimethoxysilane(A174) respectively.The Tg of latex resin was about 17℃,exhibiting excellent film forming.A174 had a better modified effect on acrylic latex, the film properties were the best when the content of A174 was 10%,water resistance reached 110 hours,water absorbtion was 4.5%.Waterborne metalic coating was prepared by silicone modified acrylic copolymerization latex,waterborne aluminum and waterborne additives.The rheological control agent, celluloseacetate butyrate(CAB),on the stability of metalic coating and glossiness were investigated.The results showed that when the content of CAB,aluminum particles were 1.5% and 20% respectively,the stability of latex and film properties were better.Ambient crosslinkable metalic coating could reduce the―dissolution‖effect of clear coating on metalic coating.
【Key words】 Waterborne emulsion coating; Ambient crosslinking; Core-shell structure; Organic silicone; Water resistance;
- 【网络出版投稿人】 华南理工大学 【网络出版年期】2012年 01期
- 【分类号】TQ316.334
- 【被引频次】2
- 【下载频次】478