丁苯胶乳_苯乙烯_甲基丙烯酸甲酯核壳乳液接枝共聚的研究

以过氧化苯甲酰(BPO)-Fe~(2+)为引发体系,硬脂酸钾和歧化松香酸皂为乳化剂,硫醇为调节剂,于600mL釜内、70℃下进行丁苯胶乳-苯乙烯-甲基丙烯酸甲酯(SBR-S-MMA)的核壳乳液接枝共聚。研究认为本体系的反应机理为:Fe~(2+)与乳化剂结合为部分油溶性化合物,再与溶解在乳胶粒中的BPO反应,生成自由基与Fe~(3+),Fe~(3+)被雕白块还原为Fe~(2+)后完成一个循环。在乳胶粒相产生的自由基与单体反应或进攻橡胶链,从而引起链引发和链增长反应。S和MMA接枝聚合的初始速率(R_(PO))与[BPO]~(0.5)成正比,R_(PO)随反应温度的升高而增大,随硫醇用量的增加而减小。该体系S和MMA两步接枝反应的表观分解活化能分别为16.56kJ/mol和17.50kJ/mol。     

甲基丙烯酸甲酯生产工艺及技术经济比较

从技术性和经济性角度评述了甲基丙烯酸甲酯的生产工艺,包括丙酮氰醇(ACH)法、异丁烯／叔丁醇法、乙烯法和异丁烷氧化法,认为异丁烯直接氧化工艺具有原料来源广泛、收率高、环境污染小的特点。     

5—（6—甲基—2—吡啶）—亚甲基罗丹宁光度法测定金的研究

研究了５－（６－甲基－２－吡啶）－亚甲基罗丹宁（ＭＰＭＲ）与金的显色反应,在ｐＨ＝５．６醋酸－醋酸铵缓冲介质中,吐温－８０存在下,ＭＰＭＲ和Ａｕ（Ⅲ）生成黄色产物,λｍａｘ＝４５０ｎｍ,ε＝８．１６×１０＾４Ｌ／（ｍｏｌ·ｃｍ）,Ａｕ（Ⅲ）含量在０￣１．６μｇ／ｍｌ范围内符合比尔定律。方法用于矿石中金的测定,其结果令人满意。     

Preparation of monoglycerides by guanidine-catalyzed processes

Glycerolysis of methyl stearate and tristearin has been carried out in the presence of alkylguanidines—strong nonionic bases—as catalysts. When applied at 10 mol%, 1,5,7-triazabicyclo [4.4.0]dec-5-ene, 1,2,3-tricyclohexylguanidine, and 1,3-dicyclohexyl-2-n-octylguanidine give monoglycerides in more than 90% selectivity, in a maximum of 6 h reaction time.     

Fast formation of high-purity methyl esters from vegetable oils

Experiments have confirmed that the base-catalyzed methanolysis of vegetable oils occurs much slower than butanolysis because of the two liquid phases initially present in the former reaction. For the same reason, second-order kinetics are not followed. The use of a cosolvent such as tetrahydrofuran or methyl tertiary butyl ether speeds up methanolysis considerably. However, like one-phase butanolysis, one-phase methanolysis initially exhibits a rapid formation of ester, but then slows drastically. Experiments show that the half-life of the hydroxide catalyst is too long to explain the sudden slowing of the reaction. Similarly, lower rate constants for the methylation of the mono- and diglycerides are not a reasonable explanation. Instead the cause has been identified as the fall in polarity which results from the mixing of the nonpolar oil with the methanol. This lowers the effectiveness of both hydroxide and alkoxide catalysts. Increasing the methanol/oil molar ratio to 27 in the one-phase system raises the polarity such that the methyl ester content of the ester product exceeds 99.4 wt% in 7 min. This has obvious implications for the size of new methyl ester plants as well as the capacity of existing facilities.     

丙烯酸阴极电泳漆的研制

介绍了采用甲基丙烯酸缩水甘油酯与常用的丙烯酸单体通过溶液聚合,制备丙烯酸阴极电泳漆的简单可行方法。研制的电泳漆克服了环氧-聚氨酯阴极电泳漆的缺点,具有可着色性、高装饰性、高耐候性等特点。讨论了影响电泳漆性能的诸种因素。列举了电泳原漆的技术指标、施工参数和漆膜性能指标。     

高氯氯化聚乙烯对CR与MMA接枝共聚合的影响

以甲苯为溶剂,在９０℃条件下,研究了１０份氯含量为５７％的高氯氯化聚乙烯（ＨＣＰＥ）对１００份粘接型氯丁橡胶与７５份甲基丙烯酸甲酯（ＭＭＡ）接枝共聚合的影响。结果表明,该体系与无ＨＣＰＥ体系相比,ＭＭＡ转化率约提高４０％,产物接枝效率约高５０％,接枝度约高９０％。产物含有较高相对分子质量的级分,相对分子质量分布较宽,并且有较好的物理机械性能和较高粘接强度。     

气相羟醛缩合法制MA及MMA研究进展

介绍了以丙酸或丙酸酯为原料,用敢相羟醛缩合法制甲基丙烯酸及甲基丙烯酸甲酯的研究进展,催化剂载体,负载离子形式,反应条件等对催化剂性能的影响,以及催化剂再生工艺的研究成果及动态,指出气相羟醛缩合法合成ＭＡ及ＭＭＡ是今后的发展方向。     

高吸油性树脂的合成及性能研究

以甲基丙烯酸十二酯和甲基丙烯丁酯为单体、水为分散相、过氧化苯甲酰为引发剂,采用悬浮聚合法合成高吸油性树脂。研究了交联剂浓度、共聚单体比、引发剂用量、水油比、分散剂用量和反应温度等对高吸油性树脂性能的影响。     

橡胶丝弹性垫用聚氨酯胶粘剂的制备

以多元醇三羟甲基丙烷,多异氰酸酯为原料制备出橡胶丝弹性垫用聚氨酯胶粘剂,并考察了多异氰酸酯品种,多元醇品种及分子量等因素对该胶粘剂性能的影响。