Intermacromolecular complexes by in situ polymerization

Hydrogen-bonded complexes of poly(acrylic acid) and poly(ethyl oxazoline) (PEOx) were prepared by photopolymerization of acrylic acid in which PEOx was dissolved. The glass transition temperatures (T_g) of the complexes are not only higher than those of the blends but also higher than the T_g value of either component polymer. The complexes dissolve in strong proton-accepting solvents like dimethyl formamide or dimethyl sulphoxide (DMSO), are swollen to various degrees in water and methanol, but are resistant to swelling by dioxane. When the density of hydrogen bond donor groups in the chain is reduced by 50% with the use of a copolymer of acrylic acid and methyl methacrylate, intermolecular association still takes place, although the affinity of complexation is reduced to some extent. When interpenetrating networks (semi-IPNs) are prepared by this method, about half of the PEOx can be extracted by DMSO after 4 days. The incomplete removal is probably a result of topographical constraints against diffusion.     

丙烯酸乙酯合成反应产物的GC／MS分析

本文叙述了丙烯酸乙酯合成产物的ＧＣ／ＭＳ分析．从分析结果看出，本应在酯化反应前除去的ＣＨ３Ｃｌ３仍有较大的含量，这也许是导致丙烯酸乙酯被氯代的原因。     

催化干气的利用

炼厂气含C_1～C_4组份,未被回收利用。催化裂化干气中含乙烯10％～20％,氢50％～70％。采用膜分离技术从重油催化裂化干气中回收氢气,制氢成本低,能源利用合理;介绍了从催化裂化干气中回收乙烯的方法及乙苯的利用。指出炼油厂采用膜分离技术回收氢及用催化裂化干气中的乙烯生产苯乙烯,是合理利用石油副产物的有效途径。     

In situ esterification of rice bran oil with methanol and ethanol

In situ esterifications of high-acidity rice bran oil with methanol and ethanol and with sulfuric acid as catalyst were investigated. In the esterification with methanol, all free fatty acids (FFA) dissolved in methanol were interesterified within 15 min, and it was possible to obtain nearly pure methyl esters. The amount of methyl esters obtained from a given rice bran was dependent on the FFA content of the rice bran oil. In the esterification with ethanol, it was not possible to obtain pure esters as in methanol esterification, because the solubilities of oil components in ethanol were much higher than those in methanol.     

Synthesis,characterization, and rheological studies of methacrylic acid–ethyl acrylate–diallyl phthalate copolymers

Copolymerization of methacrylic acid (MAA) and ethyl acrylate (EA) was performed by the emulsion polymerization technique in the presence of a mixture of ionic and nonionic emulsifiers, at 85°C, using potassium persulfate as initiator (0.16 wt % of monomer). The molar ratio of MAA : EA varied between 44 : 56 and 54 : 46 in the monomer feed. Copolymers of MAA and EA were synthesized by incorporating diallyl phthalate (DAP) with varying concentrations (0–1.7 mol % of total monomer) in the feed. A copolymer latex of MAA, EA, and DAP was also prepared by the variable feed process. The intrinsic viscosity and gel content were determined. Copolymers were characterized by IR and NMR spectroscopic techniques. The composition of copolymers was determined by ¹H‐NMR spectra and sequential distribution from ¹³C{¹H}‐NMR spectra. The pH of the copolymer emulsion varied between 3 and 10 by addition of aqueous ammonia (23% w/w) and its effect on Brookfield viscosity was studied. The effects of copolymer composition, crosslinking agent concentration in the feed, monomer feed process, polymer solid contents, and shear rate on Brookfield viscosity were studied at pH ～ 8. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1430–1441, 2003     

苯甲酰丙烯酸乙酯中主要杂质的定性分析与转化

顺丁烯二酸酐与苯在三氯化铝的存在下,经傅-克反应生成苯甲酰丙烯酸,在强酸性水介质中,若温度高于35℃,则部分发生与水的加成反应生成苯甲酰乳酸。含苯甲酰乳酸的苯甲酰丙烯酸在浓硫酸的存在下与无水乙醇反应,可分别生成苯甲酰丙烯酸乙酯和苯甲酰乳酸乙酯。而苯甲酰乳酸乙酯在二甲苯中回流可脱去一分子水而转变为苯甲酰丙烯酸乙酯,从而使苯甲酰丙烯酸乙酯的纯度从85%提高到93%。     

四氢噻吩的生产技术与市场分析

四氢噻吩是城市燃气的首选加臭剂,随着我国西气东输等工程的建设成功,其市场前景广阔.文章介绍了四氢噻吩的生产工艺和市场情况,并对四氢噻吩的发展提出了良好建议.     

固体超强酸SO4^2-/Fe2O3-CoO催化合成己酸乙酯

以固体超强酸SO4^2-/Fe2O3-CoO为催化剂，通过己酸和乙醇反应合成了己酸乙酯。实验结果表明，固体超强酸SO4^2-/Fe2O3-CoO对酯化具有较高的催化活性，反应的最佳条件为：己酸0．2mol，n（乙醇）：n（己酸）：1．8：1．0，催化剂用量为0．8g（以0．2mol己酸为准），带水剂用量为12mL，反应时间为2h，其酯化率可达97％以上。     

表面活性剂对葡甘聚糖复合乳液稳定性的影响

以 Span、Tween 系列非离子活性剂为乳化剂,葡甘聚糖（KGM）和乙基纤维素（EC）为分散相,考察 KGM/EC 乳液体系的抗聚并稳定特性。根据乳液稳定性理论分析,认为非离子活性剂分子亲油基团的结构及其与油相分子的相似度对乳液油水界面粘性及相应乳液抗聚并稳定性会产生较大影响。详细讨论了不同 HLB 值对 KGM/EC 乳液的冻融稳定性、贮存稳定性及化学稳定性的影响。     

乙基纤维素微胶囊红磷的制备及改性

目前微胶囊红磷大多采用原位聚合法制备,工艺较为复杂,且囊壳原料可能对环境造成危害.为解决这一问题,以可降解材料乙基纤维素(EC)为囊壳,采用相分离法在常温、中性条件下制备微胶囊红磷(MRP);为进一步增强MRP使用性能,添加正硅酸乙酯(TEOS)作为改性材料,在碱性条件下制备SiO_2凝胶/EC复合囊壳微胶囊红磷(SiMRP).对所得样品进行FTIR、形态及XPS分析,观察样品形态并计算包覆率;对样品进行热稳定性分析、吸湿率测定及安定性测试.实验结果表明:采用相分离法可对红磷实现有效包覆,囊壳包覆率为88.2%;EC囊壳提高了红磷的热稳定性,着火点温度较RP提升50℃; MRP 10日后吸湿率降至6.8%,摩擦感度降至34%;添加1 mL TEOS改性后的SiMPR样品包覆率达94.1%,热稳定性较MRP进一步增强,着火点温度较MRP提升90℃;SiMRP 10日后吸湿率降至4.5%,摩擦感度降至20%.