UV固化涂料用水性聚氨酯及微凝胶的制备

以异佛尔酮二异氰酸酯、聚醚多元醇、二羟甲基丙酸、丙烯酸-β-羟内酯为原料．合成了自乳化水性聚氯酯光敏性树脂，经三乙醇胺中和后，可得到100nm，粒径大小的稳定体系．用红外光谱对树脂结构进行分析，讨论了胺中和度对涂膜的影响。用合成的微凝胶对涂膜进行改性研究．结果表明，随着微凝胶的加入．涂膜的耐水性、硬度等性能有较大的改善。     

Golden and Silver–Golden Chitosan Hydrogels and Fabrics Modified with Golden Chitosan Hydrogels

Golden and silver–golden chitosan hydrogels and hydrogel-modified textiles of potential biomedical applications are investigated in this work. The hydrogels are formed by reactions of chitosan with HAuCl₄·xH₂O. For above the critical concentration of chitosan (c*), chitosan–Au hydrogels were prepared. For chitosan concentrations lower than c*, chitosan–Au nano- and microgels were formed. To characterise chitosan–Au structures, sol–gel analysis, UV–Vis spectrophotometry and dynamic light scattering were performed. Au concentration in the hydrogels was determined by the flame atomic absorption spectrophotometry. Colloidal chitosan–Au solutions were used for the modification of fabrics. The Au content in the modified fabrics was quantified by inductively coupled plasma mass spectrometry technique. Scanning electron microscopy with energy dispersion X-ray spectrometer was used to analyse the samples. Reflectance spectrophotometry was applied to examine the colour of the fabrics. The formation of chitosan–Au–Ag hydrogels by the competitive reaction of Au and Ag ions with the chitosan macromolecules is reported.     

Thermo-sensitive poly(N-vinylcaprolactam-co-acetoacetoxyethyl methacrylate) microgels: 1—synthesis and characterization

In the present paper, polymeric microgels have been prepared by surfactant-free emulsion co-polymerization of acetoacetoxyethyl methacrylate (AAEM) and N-vinylcaprolactam (VCL) in water with water-soluble azo-initiator 2,2′-azobis(2-methylpropioamidine) dihydrochloride (AMPA). It was found that the particle diameter decreased gradually when higher amounts of AAEM were used in monomer mixture. Obtained microgels possess lower critical solution temperature (LCST) in water solutions, so rapid decrease of the particle size was observed at elevated temperatures. As was found using simultaneous static and dynamic light scattering, microgels undergo soft sphere–hard sphere transition during heating.     

双功能化、双重响应聚（N-异丙基丙烯酰胺）基微凝胶的研究

为制备具有特殊层次结构的多功能化微凝胶,利用N-异丙基丙烯酰胺（NIPAM）为温敏性单体、甲基丙烯酸（MAA）为pH敏感单体、聚乙二醇甲基丙烯酸酯（PEGMA）为反应性稳定剂,通过沉淀聚合合成了内部富含羧基、表面富含羟基的一系列共聚物微凝胶。利用滴定法测定了微凝胶中羧基的含量。透射电镜和动态光散射表明得到的微凝胶几乎是单分散的。变温动态光散射和浊度测定结果表明,所制备的微凝胶具有良好的pH-响应性,随温度改变呈现两级体积相转变。     

自由基活性微凝胶及星形聚苯乙烯的合成

本文由苯乙烯—对氯甲基苯乙烯—二乙烯基苯的三元共聚反应合成了聚苯乙烯微凝胶,通过铜试剂对氯的取代反应,得到了具有自由基引发活性的微凝胶;用其引发苯乙烯聚合得到星形聚苯乙烯。     

阴极电泳涂料用微凝胶的合成及应用

通过两种方法合成含可交联型硅氧烷基团的微凝胶溶液，将微凝胶溶液作为添加剂应用到阴极电泳涂料中，可使涂料获得低颜基比、高防腐性能、高耐油污性等特性.     

聚氨酯微凝胶粒子在稀溶液中的行为

利用激光光散射检测手段,研究了具有交联结构的大分子即微凝胶在稀溶液中的行为,发现微凝胶在溶液中的行为与线型大分子有很大区别。文中所合成的微凝胶在溶液中极容易形成分子簇,并且分子簇的形成与解离处于不平衡状态。微凝胶粒子的粒径及其分布与微凝胶的交联度、溶液浓度以及溶解时间相关。     

Scale-Spanning Strong Adhesion Using Cellulose-Based Microgels

Adhesive gels derived from biobased sustainable materials have extremely broad application prospects, such as in flexible smart materials and biomedicine fields. Combining high toughness and strong, persisting repeatable adhesion has always been a daunting challenge for adhesive gels. However, bulk gels based on polysaccharides as the most abundant bio-based compounds usually possess a high toughness but weak interfacial adhesion due to the strong hydration potential. Herein, a novel kind of highly tough microgel membranes with rough surfaces is fabricated using loosely chemically cross-linked dihydroxypropyl cellulose (cDHPC) microgels (average size = 1.25 ± 0.03 µm). Such microgel membranes exhibit strong, instant, and persisting adhesion to various substrates with different surface roughness. Slight chemical cross-linking and multiple physical interactions within microgels and resulting microgel membranes lead to high tensile strength and toughness of 0.23 ± 0.03 MPa and 73.8 ± 9.3 KJ m⁻³, respectively. The maximum adhesive strength and debonding work exceed 320 ± 0.50 KPa and 160.97 ± 0.20 J m⁻², respectively. After five cycles (re-lap after detaching), the adhesive strength still remains above 200 KPa. Their adhesive properties outperform most bio-based adhesive gels and even petroleum-based gels, which are based on synergistic molecular and microscaled topological interactions.     

Microgelation of unsaturated polyester resins by static and dynamic light scattering

The microgelation phenomenon during the curing of unsaturated polyester resin was investigated by both static and dynamic light scattering before gelation. The results of static light scattering revealed that the polymer molecular weight increased with degree of curing. The second virial coefficient, A₂, decreased slowly in the initial stage of curing and decreased dramatically at a conversion around α ∼ 8.7%, indicating a drastic decrease of compatibility between the polyesters and styrene. Two modes of the size distribution of the microgel particles during curing were observed by dynamic light scattering. The small particles consist of primary unsaturated polyester molecules. The large ones consist of microgel particles formed by linking adjacent polyester molecules. The sizes of the microgel particles increased in the initial stage of curing, then decreased slightly at a conversion of α ∼ 8.7%, which was due to the intramolecular crosslink reaction of the microgel particles. The experimental results revealed that the compatibility between polyesters and the styrene monomer became worse as the intramolecular crosslinking reaction inside the microgel particles caused a tight packing of the micro-gel molecules. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 871–878, 1998     

高温高盐产水气藏微胶堵水封堵特性实验

针对我国西北地区THN、S3、KL等深层高温高盐(井深超过5 000 m,温度140℃,矿化度20×10~4 mg/L)砂岩有水气藏,现有的常规堵水和选择性堵水技术难以有效解决气井排水采气和有效堵水恢复气井产能的问题。为此,有针对性地研制和筛选了能够在高温高盐条件下实现二次交联的丙烯酰胺微胶体系WJ-1,并进行了一系列堵水性能评价实验,包括注入压力、阻力系数、耐冲刷性及对气水两相渗透率的影响等。通过实验证实了微胶体系WJ-1成胶后的抗温抗盐特性良好,能达到THN、S3、KL等高温高盐深层产水气藏深部堵水的要求,该堵剂成胶后能有效封堵高渗孔道中的水侵,让气体的通过能力明显大于水的通过能力,表明注入微胶体系WJ-1能起到一定的"堵水不堵气"的效果。此外,进一步对WJ-1微胶体系的孔隙结构特征开展了核磁共振实验分析,测试了岩心中注入WJ-1微胶体系封堵后的T2谱图,结果显示其对水的封堵强度明显大于对气的封堵强度,进一步证实了所研制堵剂的选择性封堵能力。