丙二醇

In the three systems, system realizes the crosslinking of PVC bases on the peroxide crosslinking mechanism, the tensile strength of crosslinked PVC has been improved somewhat, the IR spectrum of gel demonstrates that there are characteristic absorption peaks of n-alcohol that belongs to ethanol amine and benzenoid group. From the analysis of gel structure , deduces that the mechanism of crosslinking reaction: under the initiations of peroxide and high temperature, PVC yields macromolecules free radicals, at the same time , styrene"s polymerization and grafting onto PVC takes place, at last the system forms crosslinking structure through coupling between radicals; confirms that triethanol amine can absorb HC1 produced by degradation of PVC, so improves the crosslinking efficiency of peroxide, decreases the HCl"s promotion for PVC"s degradation; deduces that triethanol amine can activate the PVC macromolecules and prolong the free radicals" life-time of PVC macromolecules; the effect to the PVC macromolecule makes styrenes graft reaction easy, and thus improves the crosslinking efficiency.

三种体系中三乙醇胺/过氧化二异丙苯/苯乙烯体系基于过氧化物交联机理实现了聚氯乙烯的交联，聚氯乙烯交联后拉伸强度有一定提高，凝胶红外光谱分析证实了凝胶结构中含有乙醇胺的伯醇基团特征吸收和苯环的特征吸收，由凝胶结构分析，推断出交联反应的机理：聚氯乙烯在过氧化物和热作用下产生大分子自由基，苯乙烯在过氧化物和大分子自由基的作用下发生聚合和接枝反应，最终通过自由基之间的偶合产生交联；证实三乙醇胺可以吸收聚氯乙烯分解产生的HCl，提高了过氧化物的交联效率，消弱了HCl对聚氯乙烯降解的促进作用；推断三乙醇胺可以活化聚氯乙烯大分子并有可能使聚氯乙烯大分子自由基存在的时间得以延长，对聚氯乙烯大分子的作用使苯乙烯的接枝反应易于发生，从而提高了交联效率。

A process for the carbonylation of allylic butenyl ether (for example, methyl crotyl ether, 3-methoxybutene-1 and mixtures thereof) or mixture of butadiene and alcohol and production of beta-gamma unsaturated carboxylic acid esters (for example, methyl-3-pentenoate) utilizing a rhodium-containing catalyst for example, dicarbonylacetylacetonate rhodium(I or the like promoted with an iodide-containing compound (for example, HI, AlI3, SnI4, TiI4, CrI3, and CoI2 or the like).

一种将烯丙型丁烯基醚(如甲基巴豆基醚、3－甲氧基丁烯－1及其混合物)或者丁二烯与醇的混合物羰基化的方法，以及由含碘化物化合物(如HI、AlI3、SnI4、TiI4、CrI3和CoI2或等效物)促进，用含铑催化剂如二羰基乙酰丙酮酸铑(I或其等效物制备β－γ不饱和羧酸酯(如甲基－3－戊烯酸酯)的方法。

Given the current complexity of industrial recovery of 3'-methyl-2'-butenyl 3, 3-dimethyl-pentenoate and the decomposition problems with 2-methyl-1-butene, research was conducted on a process for direct recycling of MBDP involving an ester exchange reaction of MBDP with either methanol, trimethyl orthoacetate, or solutions of methanol and trimethyl orthoacetate.

针对目前工业上回收3，3-二甲基－4-戊烯酸－3'-甲基－2'-丁烯酯工艺复杂、异戊烯大量分解问题，研究了MBDP直接返回循环使用工艺，MBDP与甲醇、原乙酸三甲酯或与甲醇原乙酸三甲酯混合溶液进行酯交换反应的回收新工艺，比较了四异丙基钛酸酯、甲醇钠、氢氧化钾用作酯交换催化剂的效果，筛选出回收MBDP&一锅煮&最佳工艺：按照n：n：n：n＝1.0：9.8：9.2：0.05物质的量比投料，74℃~78℃反应21h，MBDP转化为贲亭酸甲酯和异戊烯醇，单程转化率87.7%，用85%的磷酸中和甲醇钠，蒸出甲醇，直接用于合成贲亭酸甲酯。

Then two star-shaped oligomers with designed molecular weights 5000 g mol-1 and 10000 g mol-1, respectively, were synthesized from D, L-lactide and glycolide as raw materials and pentaerythritol as initiator under catalysis of dibutyltin oxide.

以合成的丙交酯和乙交酯为原料，季戊四醇为引发剂，氧化二丁基锡为催化剂合成出设计分子量为5000和10000两种预聚物。

Promoted by metal dysprosium, aldehydes and ketones could react smoothly with propargyl bromide to afford the corresponding homopropargylic alcohol s in good to excellent yields, and no allenic alcohols were found.

在金属镝的促进下，醛、酮可与炔丙基溴反应，高选择性高产率地得到相应的高炔丙醇，没有发现连二烯醇的存在。

Ingredients:shea butter extract, cetearyl alcohol, hexadecyl trimethyl ammonium bromide, methylcyclohexyldimethoxy silane, poly dimethyl siloxane, tetradecanoic acid isopropyl ester, glycerol, amino silicone oil.

成分：，乳木果提取液，十六，十八混合醇，十六烷基三甲基氯化铵，环甲基硅氧烷，聚二甲基硅氧烷，肉豆蔻酸异丙酯，甘油，氨基硅油。

R-4-Methyl-δ-valerolactone was transformed into-methyl 5-bromo-4-methylpentanoate (5) which is a stable and easily reserved reagent.

首次利用甾体皂甙元氧化降解废弃物-4-甲基－δ-戊内酯合成了松叶蜂性信息素(25，3S，7S)-3，7-二甲基－2-十五醇乙酸酯(2)和丙酸酯(3)。

The chlorin e6 7 and chiorin 11 were oxidized further with osmium oxide in the same oxidization condition to yield bateriochlorin 8 and 12, respectively.

卟吩醛2在碱性条件下转化为卟吩e6三甲酯7，2与烷基溴化镁的格氏反应给出脱镁叶绿酸醇9，选择高钌酸四丙基铵和N-甲基吗啉N-氧化物将3-位羟基氧化成羰基，所生成的卟吩二酮10在酸性条件下脱去甲酸甲酯生成焦脱镁叶绿酸衍生物11，用四氧化锇对7和11实施氧化，则分别转化为细菌卟吩衍生物8和12。

In this thermodynamic study, the minimum requirements in molar fraction of the solvents (x3) on the azeotropic feed plate are: 0.20 for N,N-dimethylformamide, 0.36 for 2-ethoxyethanol, 0.40 for 1-pentanol and 0.66 for butyl propionate,.

在这个热力学研究中，共沸混合物喂料盘上各溶剂摩尔分数最小值(x3)分别是：N，N-二甲基甲酰胺：0.20；2-乙氧基乙醇：0.36；1-戊醇：0.40；丙酸丁酯：0.66。

By synthesizing the hapten LBc starting from the metabolite of bifenthrin (2-methyl-3-phenylbenzyl alcohol), LBs (2-methyl[1,1-biphenyl]-3-ylmethyl 3-carboxyl-2,2-dimethylcyclopropane carboxylate and Lby (2-methyl[1,1-biphenyl]-3-ylcarboxylic acid , Three haptens were praparaed which were used in next step.

利用联苯菊酯的代谢物联苯醇合成了联苯菊酯的半抗原LBc(2-甲基-3-苯基苄基氧基羰基丙酸)、LBs(2-甲基-3-苯基苄基-3-羧基一2，2-二甲基环丙烷羧酸)和LBy(2-甲基-3-苯基苯甲酸)。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。