高聚合物含量丙烯酸酯超微胶乳的制备

通过对一次加料法、单体预乳化法及单体两段滴加法制备超微胶乳的比较,发现单体两段滴加法的反应过程相当稳定.单体两段滴加法中,当预加单体量小于30%时,聚合过程稳定,氨化剪切后超微胶乳透光率约65%;当聚合物含量超过34%时,超微胶乳体系呈凝胶状.对胶乳的氨化剪切过程进行优化,发现加氨量有一最佳值,此时超微胶乳既保持较高的透光率 (～65%),又具有较低的粘度 (～220cp).最后,通过"单体两段滴加法乳液聚合 氨化剪切"制备了聚合物含量约为32%、乳化剂含量约为1.2%、数均粒径约为63nm、粒径分布为1.17的丙烯酸酯超微胶乳.     

EFFECTS OF PHENOL RESIN ADDITIVE ON DYNAMIC MECHANICAL PROPERTIES OF ACRYLATE RUBBER AND ITS BLENDS*

The dynamic mechanical properties of a new blend system consisting of phenol resin and polar polymer (acrylaterubber and/or chlorinated polypropylene) were investigated. It was found that the addition of phenol resin to acrylate rubberand its incompatible blend can cause a remarkable improvement in the temperature dependence of the loss tangent. As a result, the present blends are very good damping materials.     

水性丙烯酸系树脂涂料的制备、性能和应用

本文综述了丙烯酸系树脂涂料的发展概况、种类、制备方法和性能.     

壳聚糖钯催化Heck反应合成肉桂酸丁酯的研究

以天然高分子壳聚糖为载体,制得了用于Heck反应的壳聚糖钯配合物多相催化剂,用XPS对其结构进行了表征,并利用正交实验方法考察了原料配比、缚酸剂三乙胺的用量、反应温度、反应时间和催化剂的用量对碘代苯与丙烯酸丁酯Heck反应的影响.结果表明:反应因素的影响大小为:反应温度>原料配比>三乙胺用量>催化剂的用量>反应时间;在最佳的反应条件下:碘代苯与丙烯酸丁酯的摩尔比为1∶1、三乙胺9mmol、催化剂0.1g(钯含量1.88×10-2mmol)时,氮气保护下140℃反应8h,肉桂酸丁酯的产率可高达99.8%.并且该催化剂对其它丙烯酸酯的Heck反应也具有良好的催化活性.     

A novel approach to graft acrylates onto commercial silicones for release film fabrications by two-step emulsion synthesis

In this study, a two-step emulsion polymerization method was specially designed so as to effectively graft acrylate monomers onto commercial silicones and improve the properties of release films. FT-IR, DSC and grafting ratio tests showed that the grafting reaction happened and a high grafting ratio can be achieved when the silicone content was more than 20%. According to SEM-EDX result, the “sea-island” structure on the surface of release films made by acrylate-modified silicone latexes was proven. The silicones formed the continuous “sea” structure and the grafted acrylate polymers formed the segregated “island” structure. The carbon and silicon distributions were not uniform through the cross-section of release films made by acrylate-modified silicone latexes. After acrylate modification, the surface tension of silicone release films increased from 19-21 mN/m (before acrylate modification) to 30 mN/m and the release force increased from 8.1 g/in. to 47 g/in. As a result, the properties of release films have been effectively improved by our novel method for advanced applications.     

Synthesis of carboxylated chlorophyll derivatives and their activities in dye-sensitized solar cells

Chlorophyll-a derivatives possessing a carboxy group in the substituent at the 3-position were prepared by chemical modification of methyl pyropheophorbide-d bearing the 3-formyl group via a Wittig, Barbier-type, or Knoevenagel reaction. The synthetic carboxylated chlorophyll pigments were employed as dye sensitizers for solar cells and their performances were compared in a conventional device based on a mesoporous titanium dioxide electrode and a liquid electrolyte. The solar power conversion efficiency was suppressed with an increase in the length of the oligomethylene moiety between the chlorin π-system and the carboxy group, while a corresponding π-linked ethenylene spacer enhanced the efficiency.     

HIGH SOLIDS-CONTENT NANOSIZE POLYMER LATEXES MADE BY A MODIFIED EMULSION COPOLYMERIZATION

Polymer nanoparticles were prepared in the methyl methacrylate (MMA)/buty lmethacrylate (BA) emulsion copolymerization process by a modified microemulsion copolymerization method. 2-Hydroxyethyl methacrylate(HEMA), acrylate (AA) and methyl acrylate (MAA) were used as reactive cosurfactants. With this process high polymer: surfactant weight ratios (40:1 or greater),relatively concentrated (～30wt. %) latexes and small (～60nm) particle diameters were obtained.Properties of the latexes were characterized by TEM, DSC, dynamic light scattering, and IR spectroscopy.     

Synthesis of Phosphine Oxide-Carboxylic Acid Esters Bearing 9,10-Dihydro-9,10-ethanoanthracene Moiety

A bulky type of phosphine oxide-carboxylic acid bearing 9,10-dihydro-9,10-ethanoanthracene moiety was synthesized by the Diels-Alder reaction of 2-anthryldiphenylphosphine oxide and methyl acrylate, for which the structure was confirmed on the basis of 1 H NMR spectral data to be dimethyl 2-diphenylphosphinoyl-9,10-dihydro-9,10-ethanoanthracene-11,11- and 12,12-dicarboxylates.     

Studies on the Self-condensing Vinyl Living Radical Polymerization of a Novel Acrylate Inimer

IntroductionDendrimers represent a class of macro-molecules with perfectly and regularly branchedstructures.However,the synthesis ofdendrimers isnot trivial and requires multistep synthesis,theircommercial development has been limited only to afew structures[1— 3 ] . Hyperbranched macro-molecules,which posses less perfectly branchedstructures,have some similar properties to those ofdendrimers,but they can be prepared in a singlestep and one- pot reaction,so many macromolecularresearchershavef…     

六甲氧基甲基三聚氰胺-多元醇-丙烯酸酯混杂聚合中酸的双重作用

六甲氧基甲基三聚氰胺 (HMMM) 多元醇 丙烯酸酯混合体系在较高温度下可同时进行缩聚和自由基聚合并表现出加速固化、热互补、原位形成高分子合金等协同效应 .通过凝胶化时间和聚合反应速度的研究 ,发现酸既是HMMM 多元醇缩聚反应的催化剂 ,也是促进过氧化氢物分解产生自由基引发丙烯酸酯自由基聚合的催化剂 .研究还发现 ,以潜酸催化剂作为酸的来源可以使体系达到室温稳定 ,高温快速固化的目的