二聚的

HDI's molecular structure is a special saturated straight chain and it has highly unsaturated double bonds.It has such very lively and chemical properties that can be used to form polyurea with water. And it also reacts with polyurethane to form polyol, reacts with amine to biuret.

己二异氰酸酯分子具有特殊的直链饱和结构和含有高度不饱和双键的异氰酸酯基团，化学性质非常活泼，能够与水生成聚二脲，与多元醇反应生成聚胺酯，与胺反应生成缩二脲。

The invention provides a method for homopolymerizing conjugated dialkene or co-polymerizing conjugated dialkene and monovinyl aromatic hydrocarbon. The method comprises the following steps: the conjugated dialkene is homopolymerized or the conjugated dialkene and the monvinyl aromatic hydrocarbon are co-polymerized randomly. The method is characterized in that at least one alkali metal alkoxide compound expressed by the formula is used as a structure regulator; in the formula, R is linear chain or branched chain alkylidene radical having 1 to 10 carbon atoms; M is alkali metal selected from Li, Na, K, Rb and Cs.

本发明提供了一种使共轭二烯烃均聚或者使共轭二烯烃与单乙烯基芳烃共聚的方法，包括在阴离子聚合条件下使共轭二烯烃进行均聚或者使共轭二烯烃与单乙烯基芳烃进行无规共聚，其特征在于采用至少一种式所示的碱金属醇盐化合物作为结构调节剂，其中R为具有1-10碳原子的直链或支链亚烷基；以及M为选自Li、Na、K、Rb和Cs的碱金属。

On the basis of above, we utilize the technology of interpenetrating polymer network to prepare the equimolar complex-forming semi-IPNs consisting of uncrosslinked PEG and crosslinked PAA.

在此基础上，利用互穿网络技术，以聚乙二醇分子为模板制备了等摩尔复合物形成的半互穿聚合物网络，包括了未交联的聚乙二醇和交联的聚丙烯酸。

Poly(ethylene-2,6,-naphthalate) is a newly developed polyester. The chemical structure of PEN can be described by replacing the benzene ring in poly with the stiffer naphthalene ring.

聚萘二甲酸乙二酯是一种近年来获得较大发展的高性能聚酯材料，其分子结构与聚对苯二甲酸乙二酯相类似，可看作是由PET链中苯环由刚性更大的萘环所替代的产物。

By use of titration analysis, the thesis investigated various factors such as isocyanate, PE molecular weight, reacting substance molecular ratio, reacting temperature and time etc. influencing upon prepolymerization step. It was found that 2, 4-tolulene diisocyanate and 4, 4'diphenylmethane diisocyanate is more rapidly reacted with PE600 than HDI. With PE molecular weight increasing, the reacting temperature or time should be raised or extended relevantly. Thus PE2000+2HDI pre-polymerization should be better carried out under some catalyst, for example, Triethylene diamine , Dibutyltin dilaurate and Tin octoate were used.

首先采用滴定分析方法对WRPU预聚反应的影响因素进行了研究：芳香族二异氰酸酯TDI、MDI比脂肪族二异氰酸酯HDI反应活性高，其中TDI在反应初始阶段的反应速率比MDI快，不过随着反应的进行，MDI比TDI反应速率加快，这主要是因为TDI分子中的两个-NCO反应活性差异大所致；二元醇分子量越大，反应速度越慢；聚醚二元醇比聚酯二元醇的反应速度快；当分子量超过2000的二元醇与HDI进行预聚反应时，需借助适当的催化剂来加快反应速度，从而使预聚反应能够顺利进行，分别选择DABCO、TOA和DBDTL三种催化剂进行催化反应，发现不同的催化剂，其催化效果相差较大。

In this paper, the third monomer 1,4- benzenediamine was introduced into the system of pyromellitic dianhydride and 4, 4-diamino diphenyl. Polyamic acid was synthesized in N-methyl pyrrolidone by solution polycondensation. The chemical structure of the polymer obtained was characterized by infrared spectrum. The dynamic viscosity and intrinsic viscosity were measured. Studies were mainly focused on the influences of monomer solid contents, monomer adding methods on intrinsic viscosity.

本实验在常用的均苯四酸二酐和4，4'—二氨基二苯醚聚酰亚胺体系中，引入第三单体对苯二胺，采用三元共聚的办法合成出聚酰胺酸溶液，对合成产物进行了分子结构的红外光谱分析以及特性粘数、动力学粘度的测试，并讨论了单体固含量、加入方式等对聚酰胺酸特性粘数的影响。

The paper introduces the injection molding equipment, mold and molding technique for the thermotolerant engineering thermoplastic polyphenylene ether sulphone .

介绍耐高温热塑性工程塑料聚苯醚砜树脂的注射成型设备、模具和注射工艺等。相关：聚苯醚（聚2，6-二甲基苯醚），聚苯撑氧聚苯硫醚

This embodiment will illustrate that the present invention of the (poly trimethylene terephthalate) PTT laminated film performs better than its PET counterpart in terms of vapor impermeability, flexibility and warpage; its vapor impermeability is about equal to a TPT back sheet, while flexibility and warpage are better than TPT back sheet.

本实施例说明本发明聚对苯二甲酸丙二醇酯薄膜复合成的叠层膜的抗水汽渗透性、挠性和翘曲度优于多层聚对苯二甲酸乙二醇酯薄膜复合形成的叠层膜，抗水汽渗透性与TPT背板基本相当，挠性和翘曲度优于TPT背板。

Zinc diamyl dithiocarbamate antioxidant showed good synergism with antimony diakyl dithiocarbamate antiwear additive in improving the oxidation stability of modified soybean oils. The incipient oxidation temperature and induction period time of genetically modified soybean oils were improved significantly by adding polyalphaolefin and additives, and they were even better than that of the synthetic base oil PAO with the same additive formulation.

结果表明，改性大豆油的不饱和脂肪酸含量越高，其氧化安定性越差；抗氧剂二戊基二硫代氨基甲酸锌和抗磨剂二烷基二硫代氨基甲酸锑在改性大豆油中均表现出了良好的抗氧协同性能，尤其在基因改性大豆油中，聚-α-烯烃和添加剂的复配使其起始氧化温度和氧化诱导时间均超过了相同配方的聚-α-烯烃油样。

One chamber near the epidermis was filled with OCAs, and the other one was filled with isotonic saline. The dynamic changes in transmittance and the skin thickness were monitored after the application of six saturated alcohols to in vitro skin samples. From the observed results at 60 minutes, the optical clearing effects of six OCAs, i.e., glycerol, polyethylene glycol 400 (PEG400), polyethylene glycol 200 (PEG200), 1, 3-propylene glycol, 1, 4-butanediol and 1-butanol, showed in the descending order.

针对离体皮肤，建立模拟在体环境的给药方法(皮肤表面给药、真皮面与等渗生理盐水作用)，考察6种饱和醇类试剂作用后皮肤厚度及透射光强的变化。60分钟的动态观测发现，各试剂均能产生不同程度的光透明作用，皮肤光透明效果由强到弱依次为：甘油、聚乙二醇400(PEG400)、聚乙二醇200(PEG200)、丙二醇、丁二醇、正丁醇。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。