共查询到18条相似文献,搜索用时 93 毫秒
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采用逐步聚合法,选用异佛尔酮二异氰酸酯(IPDI)和聚乙二醇(PEG1000)为预聚单体,自制的端羟基季铵盐为阳离子扩链剂,利用亚硫酸氢钠对异氰酸酯基封端处理后对体系进行去离子水分散乳化,合成了一种反应型阳离子水性聚氨酯(WPU)固色剂,考察了预聚反应温度、nNCO/nOH比值以及扩链剂用量对阳离子WPU性能的影响。结果表明,当预聚反应nNCO/nOH比值为2.0、温度70℃,季铵盐扩链剂质量分数为9%(相对于预聚物)时,合成阳离子WPU性能较好;将其用于活性染料或直接染料染色棉织物的固色处理,耐皂洗牢度及耐摩擦色牢度效果良好,其中湿摩擦牢度能够达到4级。 相似文献
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聚氨酯复鞣填充剂的合成 总被引:2,自引:0,他引:2
蓖麻油经马来酸酐酯化得到羟基官能度为2.0~2.2的改性蓖麻油(MCO),将其作为多元醇成分与异佛尔酮二异氰酸酯(IPDI)、聚乙二醇1000(PEG1000)和二羟甲基丙酸(DMPA)等反应合成脂肪族耐光型聚氨酯复鞣填充剂(CPUF)。重点探讨了MCO/PEG1000、加料顺序、反应温度、DMPA用量和中和剂对乳液稳定性的影响。利用IR对聚氨酯复鞣剂的结构进行了表征。确定了工艺过程:改性蓖麻油首先同IPDI在70 ℃预聚40min,然后加入PEG1000和DMPA在80 ℃扩链100 min生成羟基终端的聚氨酯,其中m(MCO)∶m(PEG1000)=1∶1;中和剂选择三乙胺,聚氨酯复鞣剂中—COOH的质量分数为4%~5%。 相似文献
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采用聚醚多元醇、异佛尔酮二异氰酸酯IPDI、2,2-二羟甲基丙酸(DMPA)、三乙胺为主要原料,采用自乳化法合成一系列的水性聚氨酯乳液。考查了预聚温度和预聚时间、扩链时间和扩链温度对反应的影响;R值(n/n)、DMPA的用量和中和度对乳液性能的影响。结果显示,当预聚温度为60℃、预聚时间为60 min、扩-NCO-OH链温度为75℃、扩链时间为120 min时,可以保证反应的速率和生产周期;选择R=2、DMPA用量为3%、中和度为100%,可以制得稳定的、性能优异的水性聚氨酯乳液,可用于织物的防水透湿整理。() 相似文献
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《化学推进剂与高分子材料》2016,(1):64-68
以聚乙二醇(PEG)、聚丙二醇(PPG)、二苯基甲烷二异氰酸酯(MDI)为主要原料,1,4–丁二醇(BDO)为扩链剂,合成出遇水膨胀聚氨酯弹性体。研究了不同相对分子质量的PEG、多元醇配比、预聚体w(NCO)以及异氰酸酯指数(R值)对聚氨酯弹性体性能的影响。结果表明:PEG相对分子质量为1 000,m(PPG1000):m(PEG1000)=20:80,预聚体w(NCO)控制为8%~9%,R值为1.06时,制备的膨胀型聚氨酯止水材料综合性能最好。 相似文献
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通过一系列单因素平行实验,对水性聚氨酯分散体合成工艺中反应温度、溶剂、异佛尔酮二异氰酸酯(IPDI)和甲苯二异氰酸酯(TDI)的选择、聚四氢呋喃二醇(PTMG)相对分子质量等因素与水性聚氨酯的黏度、颜色、透明性等性能的关系进行了研究。结果表明,二羟甲基丙酸(DMPA)含量的大小直接影响产品的相对分子质量和体系黏度;反应温度是敏感因素,聚合反应温度在50℃~55℃。 相似文献
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Mahiran Basri Kamaruzaman Ampon Wan Md. Zin Wan Yunus Che Nyonya A. Razak A. Bakar Salleh 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1995,64(1):10-16
Monomethoxypolyethylene glycols (PEG) of molecular masses 1900 and 5000 were activated using p-nitrophenyl chloroformate to form PEG–nitrophenyl carbonates (activated PEG) with high yield (96–98%). The activated PEG was covalently attached to Candida rugosa lipase. Increasing the molar ratio of activated PEG to the enzyme increased the degree of lipase modification. These modified lipases exhibited specific ester synthesis activities on organic solvents compared with native lipase. The degree of activity enhancement depended on the size of activated PEG used and the degree of modification of the enzyme. Maximal activity was attained after exhaustive of modification. The effects of different solvents, reaction temperature, and fatty acids on the esterification activity and the stability of the modified enzyme were investigated. The optimum esterification temperature (40° C) and preference of fatty acids as acyl donors of the modified lipase were very similar to those of the native enzyme. The modified lipase exhibited higher activity non-polar solvents than in polar solvents, and showed higher temperature, solvent and storage stability then the native lipase. 相似文献
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Mary Welch Baillargeon Philip E. Sonnet 《Journal of the American Oil Chemists' Society》1988,65(11):1812-1815
Polyethylene glycol (PEG) was covalently attached to lipase (EC 3.1.1.3) fromCandida rugosa yielding a modified lipase of higher specific activity in hydrolytic and synthetic reactions in organic solvents. PEG of
molecular weights 5000 and 1900 solubilized the lipase in selected organic solvents, but PEG of molecular weight 750 was too
small to accomplish this completely. The modified lipase was 10 times more stable in water than native lipase, but was less
stable in benzene. The selectivity of the modified lipase was also altered to favor reaction with oleic versus stearic acid. 相似文献
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Fatima Mumtaz Mohammad Zuber Khalid Mahmood Zia Tahir Jamil Rizwan Hussain 《Korean Journal of Chemical Engineering》2013,30(12):2259-2263
Aqueous polyurethane dispersions (PUDs) have recently emerged as important alternatives to their solvent-based counterparts for various applications due to increasing health and environmental awareness. A series of aqueous polyurethane dispersions containing carboxylate anion as hydrophilic pendant groups were synthesized through step growth polymerization reaction using hexamethylene diisocyanate (HDI), 1,4-butanediol (1,4-BDO), dimethylol propionic acid (DMPA) and polyethylene glycol (PEG) of different molecular weight. Effect of PEG molecular weight was investigated on molecular structure, contact angle measurement, and physical and adhesive properties of PU emulsions. Fourier transform infrared spectroscopy (FT-IR) was used to check the completion of polymerization reaction. Contact angle measurement indicated that the hydrophilicity of polymer increases by increasing molecular weight of PEG with a corresponding decrease in contact angle. Results of T-peel test showed a decrease in peel strength by increasing molecular weight of PEG. Moreover, solid contents%, drying time and storage stability suggested fast drying properties and greater stability of aqueous PU dispersions. 相似文献
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采用反气相色谱法测定了不同极性的溶剂与聚乙二醇 ( PEG)的热力学相互作用参数 χ1 2 ,并探讨了色谱柱中 PEG在载体上的涂布量以及 PEG的分子量对相互作用参数的影响。研究结果表明 :在 60~90℃的温度范围内 ,烷烃类溶剂与 PEG的相互作用较弱 ,是 PEG的非溶剂 ;而乙酸乙酯和甲苯与 PEG的相互作用较强 ,是 PEG的良溶剂。流动相中溶剂探针分子仅在 PEG液膜的表层与其相互作用 ,χ1 2 的大小与PEG在载体上的涂布厚度以及 PEG的分子量无明显的相关性 相似文献
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固-液相转移催化法合成1-(2,4-二氯苯基)-2-(1-咪唑基)-乙醇 总被引:1,自引:0,他引:1
用固-液相转移催化法由1-(2,4-二氯苯基)-2-氯-乙醇与咪唑在NaOH存在下进行N-烷基化反应合成了1-(2,4-二氯苯基)-2-(1-咪唑基)-乙醇.由实验得到的反应动力学方程符合拟一级反应,提出了合理的反应机理.详细研究了催化剂、溶剂、卤代烃的卤素原子、碱的种类和用量、反应温度和搅拌速度对反应的影响.对溴化十六烷基三甲基铵(CTMAB)、苄基三乙基氯化铵(TMBAC)、四丁基溴化铵(TBAB)、聚乙二醇400(PEG400)和聚乙二醇600(PEG600)五种催化剂的活性进行了考察,结果表明,具有对称结构的TBAB和PEG400的催化活性最强.反应产率与溶剂极性密切相关,中等极性的四氢呋喃(THF)、丙酮是合适的溶剂.低活性季铵盐CTMAB、TMBAC作催化剂时,在反应体系中加入溴化钠,能提高反应活性.快速搅拌和加热对反应有促进作用.在优化反应条件下,产率达88.5%. 相似文献