共查询到19条相似文献,搜索用时 62 毫秒
1.
2.
HEMA封端对PUA复合乳液性能的影响 总被引:2,自引:0,他引:2
采用甲基丙烯酸-β-羟乙酯(HEMA)对聚氨酯预聚体进行封端,合成含有双键的水性聚氨酯乳液,并制备了核壳接枝的聚氨酯-丙烯酸酯(PUA)复合乳液.通过对PUA复合乳液和涂膜性能测定,讨论了HEMA用量对PUA乳液和涂膜性能的影响.结果表明,随着HEMA用量增加,PUA复合乳液的稳定性和涂膜热稳定性得到了提高.当HEMA用量为75%时,PUA综合性能优良. 相似文献
3.
4.
以自制的亲水性聚氨酯丙烯酸酯(PUA)预聚体为高分子乳化剂,与自制的环氧丙烯酸酯(EA)树脂充分混合后,采用相反转乳化法制备了可UV固化的具有不规则核壳结构的PUA/EA复合乳液。利用傅里叶变换红外光谱对水性PUA合成过程以及复合乳液UV固化前后进行了表征,表明合成得到了目标产物且UV固化良好。透射电镜(TEM)测试表明,复合乳液呈不规则的核壳结构,且EA含量不同时核壳结构也不同。重点讨论了羧基含量对乳液相反转过程、PUA预聚体的乳化能力、复合乳液以及固化后涂膜性能的影响,结果表明,相反转过程中体系黏度与电导率有类似的变化趋势,最大值均随羧基含量的增加而增加,且出现得越来越晚;PUA预聚体的乳化能力随羧基含量的增加而增加,但超过2.3%后变化不再明显;此外,随羧基含量的增加,乳液的平均粒径变小、外观越来越透明、黏度变大、贮存稳定性变好,而相似文献
5.
6.
7.
8.
9.
含氟乳化剂FC80含量对丙烯酸酯乳液共聚物性能的影响 总被引:3,自引:0,他引:3
研究了含氟乳化剂 FC80含量对丙酸酯乳液共聚物性能的影响。结果表明随 FC80含量从0 .0 1 %增加到 0 .3% ,丙烯酸酯乳液共聚物的表面张力和粘度下降 ;耐酸性增强 ,p H值稳定范围增宽 ;乳液粒子直径下降 ;稀释和贮存稳定性好 ;耐电解质稳定性呈现抛物线变化。 FC80含氟乳化剂的最佳用量以 0 .0 5 %到 0 .1 %为宜。 相似文献
10.
丙烯酸酯改性的水性聚氨酯乳液性能优异、用途广泛,是当前涂料工业研究的一个热点.采用原位乳液聚合法,先制得水性聚氨酯(PU)预聚物,然后加入引发剂和甲基丙烯酸甲酯(MMA),通过自由基乳液聚合得到聚氨酯-丙烯酸酯(PUA)复合乳液,并通过傅里叶变换红外光谱、凝胶渗透色谱、粒径分析仪等对其进行表征.研究了NCO/OH比值、二羟甲基丙酸(DMPA)含量、MMA含量及三乙胺与DMPA的摩尔比值对PUA乳液性能及外观的影响.发现当NCO/OH=1.3~1.4,—COOH含量为2.6%左右,MMA含量为20%~30%,三乙胺与DMPA的摩尔比值为90%~100%时,所得PUA乳液综合性能较好. 相似文献
11.
The polyurethane acrylate (PU-A) containing double bond and COOH group was synthesized by stepwise reaction of 2,4-toluene diisocyanate (TDI), polyetherdiol (PPG), dimethylolpropionic acid (DMPA), and 2-hydroxpropyl acrylate (HPA), and the PU-A was neutralized with triethylamine (TEA) and self-emulsified in water to form the PU-A emulsion seed. Adding methyl methacrylate (MMA) into PU-A seed, the seeded emulsion copolymerization of MMA onto PU-A seed had been carried out at 80°C under the soap-free condition to obtain anionic latex of P(UA-MMA). The kinetic behavior of the seeded emulsion copolymerization, the MMA grafting ratio, and the crosslinking copolymer were investigated. IR spectra showed that it did form the P(UA-MMA) copolymer. The measurements revealed that the structure of the P(UA-MMA) copolymer, its latex properties and the cast film were significantly influenced by the amounts of HPA, DMPA, and MMA. The experimental results indicated that with DMPA increased, the particle size of P(UA-MMA) latex decreased, but the tensile strength of its cast film increased. Adding a small amount of HPA, it could improve the tensile strength of the cast film. With MMA content increased, the distribution of the particle size of P(UA-MMA) latex became narrow, whereas under certain amount of MMA, the tensile strength of the cast film was enhanced. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 941–947, 2001 相似文献
12.
13.
在种子乳液聚合中加入发泡剂偶氮二甲酰胺(AC),制备了可发气核壳结构复合微球。探讨了AC用量对以聚苯乙烯(PSt)微凝胶为种子,St或甲基丙烯酸甲酯(MMA)为壳层单体的2种体系稳定性及转化率和反应速率的影响。结果表明,以MMA为壳层单体的聚合体系是较理想体系。当AC用量从1g增加到8g时,以St为壳层单体体系的最终转化率从96.2%下降到74.2%,以MMA为壳层单体体系的最终转化率基本不变,保持在96%左右。但AC的加入使以MMA为壳层单体体系的反应速度最大值的出现时间推后了10min,且其值仅为未加入AC体系的1/2左右。 相似文献
14.
15.
Adriano Marim de Oliveira Maria Lúcia Caetano Pinto da Silva Gizelda Maria Alves Pedro Carlos de Oliveira Amilton Martins dos Santos 《Polymer Bulletin》2005,55(6):477-484
Summary This paper presents a methodology of encapsulation of TiO2 (Titanium dioxide) by emulsion polymerization on the proposal to modify the physical-chemical properties of the pigment surface.
In the proposed methodology the TiO2 was previously modified by isopropoxy-titanium-tri-isostearate, before being encapsulated by emulsion polymerization using
Methyl Methacrylate as monomer.
The effects of the polymerization process, type of initiator and monomer concentration in the efficiency of encapsulation
were studied. The encapsulated pigment was characterized by Thermogravimetric Analysis (TGA), Light Scattering (LS) and Transmission
Electron Microscopy (TEM). 相似文献
16.
17.
18.
19.
以异佛尔酮二异氰酸酯(IPDI)、混合多元醇、甲基丙烯酸甲酯(MMA)为主要原料合成了脂肪族聚氨酯丙烯酸酯复合乳液。混合多元醇由聚碳酸酯二醇(PCDL)、聚四亚甲基醚二醇(PTMEG)、聚醚二醇(N220)以不同比例复配而成。重点探讨了PCDL与N220、PTMEG与N220及PTMEG与PCDL复配比例对乳液、胶膜性能的影响。实验发现,当PTMEG与N220以相同质量比复配且控制硬段含量在60%时,得到贮存稳定性好,胶膜硬度高、耐水、耐溶剂性能好、耐黄变性优异的PUA复合乳液。 相似文献