苯乙烯和丙烯酸-β-羟乙酯不同温度的竞聚率测定

苯乙烯和丙烯酸 β 羟乙酯不同温度的竞聚率测定吴平平吴玉芳陆琛杨全兴韩哲文（华东理工大学材料科学研究所上海２００２３７）陈顺喜朱清仁（中科院中国科技大学结构分析开放实验室合肥２３００２６）关键词苯乙烯，丙烯酸 β 羟乙酯，共聚合，竞聚率丙烯酸 β?..     

Strong influences of cocatalyst on ethylene/propylene copolymerization with a MgCl2/SiO2/TiCl4/diester type Ziegler-Natta catalyst

Using triethylaluminum (TEA), triisobutylaluminum (TIBA) or TEA/TIBA mixtures of molar ratio 75/25, 50/50 and 25/75 as the cocatalyst, five different ethylene-propylene copolymer samples were synthesized by a MgCl₂/SiO₂/TiCl₄/diester type Ziegler-Natta catalyst in a slurry polymerization process. The synthesized copolymers are strongly heterogeneous in chain structure and were fractionated into part of nearly random copolymer and part of segmented copolymer. Both polymerization activity and copolymer structure were found to be markedly changed when the cocatalyst was changed from TEA to TEA/TIBA mixtures or pure TIBA. As the content of TEA in cocatalyst increases, yield of the random part of product increases and the yield of the crystalline segmented copolymer part decreases. There is also a decrease in ethylene content of the whole product with increasing TEA amount. Copolymerization behaviors of the TEA/TIBA mixture activated catalysis systems are not simple superposition of those activated by pure TEA and TIBA. When a 50/50 TEA/TIBA mixture was used as cocatalyst, the copolymerization activity became the highest, and yields of both the random copolymer part and the segmented copolymer part are close to the highest level. On the other hand, both parts of the copolymer produced with a 50/50 TEA/TIBA mixture are relatively more blocky than the products of TEA or TIBA systems, and difference in ethylene content between the random part and the segmented part was the smallest. The segmented copolymer part of three typical samples was further fractionated by temperature-gradient extraction fractionation into fractions of different ethylene content and sequence distribution. Changing TEA content in the cocatalyst exerted strong influences also on the fraction distribution of the segmented part of copolymer.     

聚芳醚亚砜的合成与表征

以二苯醚和二氯亚砜为主要单体 ,在无水AlCl3/CH2 ClCH2 Cl/NMP催化剂溶剂体系中进行低温溶液共聚 ,合成聚芳醚亚砜 (PPOS) ,研究了AlCl3/NMP用量及单体摩尔比对聚合反应的影响 .用IR、DSC、TG和X ray等对PPOS进行结构和性能的分析与表征 ,研究结果表明 :PPOS属无定形聚合物 ,具有较高的玻璃化转变温度 (Tg) ,软化温度在 2 6 0℃左右 ,在加热过程中出现二个热分解温度     

ZnGA-MMT catalyzed the copolymerization of carbon dioxide with propylene oxide

Zinc glutarate (ZnGA) synthesized from zinc oxide and glutarate acid was dispersed on the surface of acid-treated montmorillonite (MMT) in quinoline to prepare ZnGA-MMT catalyst. The results of X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) measurements indicated that the ZnGA on the surface of acid-treated MMT had the same crystalline structure as pure ZnGA. Copolymerization between CO₂ and propylene oxide (PO) was carried out under optimized reaction conditions using ZnGA-MMT catalyst, consequently giving poly(propylene carbonate) (PPC) with high molecular weight in a very high yield (115.2 g polymer per gram of ZnGA). The obtained PPCs were investigated using ¹³C NMR and FTIR spectra, showing a completely alternating structure. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) examinations showed the PPCs with a high transition temperature of 38 °C and a very high decomposition temperature (>250 °C) due to the presence of MMT residual in polymer.     

两亲性丙烯酸酯共聚物的聚合研究

利用过氧化苯甲酰为引发剂探讨了甲基丙烯酸β－羟乙酯和丙烯酸长链烷基酯的自由基共聚合。重点讨论了合成条件如溶剂、沉淀剂、引发剂用量、单体配比、反应时间等对共聚反应的影响以及各种聚合条件对该共聚物的组成、结构和性能的影响。并用ＩＲ，ＧＰＣ，＾１３ＣＮＭＲ等手段对共聚物进行了表征。     

Radical copolymerization of citraconic acid with styrene in dioxane solution

Styrene and citraconic acid (CA) were copolymerized in the dioxane solution ranging mole fraction of CA in feed from 0.1 to 0.9 at 70 °C. The terminal and penultimate models were used to fit the copolymer composition equation. Curve fitting, Mayo-Lewis, Joshi-Joshi, Fineman-Ross, Ezrielev-Brokhina-Roskin, Kellen-Tüd?s methods were used to solve the copolymer equation in terminal model. Besides these methods Solver in Excel 97 was used to solve copolymer equation in terminal and penultimate models of copolymerization. Experimental mole fractions of CA and those predicted from both models are agreed within the precision of the method used for the copolymer analysis, so the copolymer composition does not permit a definite choice of the adequate copolymerization model.     

由两种单体借助酯交换反应制备三元共聚物

本文讨论了甲基丙烯酸羟乙酯和甲基丙烯酸在乙醇中进行溶液聚合时,借助酯交换反应,在该亲水体系中引入第三疏水组分,从而制备三元共聚物的可行性.     

苯乙烯在蚕丝丝胶上接枝共聚的研究

<正> 蚕丝丝胶(Silk Sercin简写SS)是由十八种氨基酸缩合而成的天然旦白,占蚕茧重量的20—30％,由于它溶于水,在缫丝过程中随废水而流失。我们曾对丝胶-金属络合物的制备及其对DL和L-3,4二羟基苯丙氨酸氧化催化活性进行了研究。本文研究了苯乙烯(St)在丝胶上接枝共聚的机理及规律,用红外光谱、差示扫描量热法、热重     

1,4-丁炔二醇的均聚及与苯乙炔的共聚研究

<正> 炔类聚合物由于具有长链π体系的结构特点,理论上可作为结构型导电聚合物,这一领域的研究工作正在迅速展开。 1,4-丁炔二醇(BD)可用PdCl_2,ZnCl_2,(Ph_3P)_2PdCl_2等多种催化剂催化聚合,得到长链共轭的聚(1,4-丁炔二醇)(PBD)。苯乙炔(PA)可用热聚合,光聚合、电聚合、自由基聚合、等离子体聚合、催化聚合等聚合方法,得到长链共轭的聚苯乙炔     

氯化聚乙烯对甲基丙烯酸甲酯／苯乙烯共聚动力学的影响

将甲基丙烯酸甲酯（ＭＭＡ）／苯乙烯（Ｓ）在氯化聚乙烯（ＣＰＥ）存在下进行悬浮溶胀接枝共聚，考察了ＣＰＥ对ＭＭＡ／Ｓ共聚动力学行为的影响．ＣＰＥ提高了聚合体系的粘度，使自动加速提前，扩散因素增加，对共聚有阻滞作用．ＣＰＥ是链转移剂，使ＭＭＡ／Ｓ共聚物分子量降低．ＣＰＥ对ＭＭＡ的吸附渗透优于对Ｓ的吸附，造成接技部分与非接技部分组成的差异．ＣＰＥ含量、溶胀时间、转化率、硫酸用量对共聚组成均有影响。