CHARACTERIZATION OF AMPHIPHILIC AND MICROPHASE SEPARATED GRAFT COPOLYMERS Ⅱ SURFACE CHARACTERIZATION AND IN VITRO BLOOD-COMPATIBILITY ASSESSMENT OF POLYSTYRENE-GRAFT-ω-STEARYLPOLY (ETHYLENE OXIDE)*

This paper reported the research results concerning the surface characterization ofpolystyrene-graft-w-stearyl poly(ethylene oxide) (PS-g-SPEO) by means of XPS,contactangle measurement and TEM, and its in vitro blood compatibility assessment by measuringthe plasma recalcification time (RT) and partial thromboplastin time (PTT). The XPSresults demonstrated that the surface and bulk composition of the PS-g-SPEO graftcopolymers differ remarkably from each other,and that SPEO component was constantlyenriched at the copolymer/air interface. Contact angle studies indicated that the surfacewater wettability can be adjusted effectively by changing the composition of the copolymer.PS-g-SPEO graft copolymers can undergo microphase separation as clearly illustrated byTEM photographs. The relationship between the surface properties of PS-g-SPEO graftcopolymer and its blood compatibility was also discussed.     

1-辛烯的Ziegler-Natta聚合动力学(Ⅰ)——稳态动力学规律

过去对C_6—C_(20)α-烯烃的Ziegler-Natta聚合动力学仅有少量研究,未发现与乙烯、丙烯的聚合行为有显著不同。但1-辛烯在烃类溶剂中的聚合是溶液聚合,这是与析出聚合的主要差别。本文发现并研究了1-辛烯以α-TiCl_3-AlEt_3催化在正庚烷中聚合时的特殊动力学行为,对此提出了初步解释。     

冠醚菁染料及其中间体的特征红外光谱

本文首次报道冠醚菁染料3,3’-二乙基-5,6,5’,6’-双骈-(15-冠-5)-硫碳菁碘盐(1)和3,3’-二乙甲基-5,6-骈-(15-冠-5)-硫碳菁碘盐(2)以及合成中间体:4’-溴5’-硝基-苯骈-15-冠-5(3),2.2’-二硝基-4,5,4’,5’-双骈-(15-冠-5)-二本基二硫化物(4),2-甲基-5,6-骈-(15-冠-5)-苯骈噻唑(5)和2-甲基-3-乙基-5,6-骈-(15-冠-5)-苯骄噻唑碘盐(6)的特征红外光谱图。     

一阶导数停流法测定药物和饮用水中的铁

本文利用Ｆｅ＾３＋离子催化Ｈ２Ｏ２氧化四甲基对苯二胺的反应，将采用停流技术获得的动力学曲线转换成一阶导数曲线，根据导数峰高值与Ｆｅ＾３＋离子浓度的线性关系测定药物和自来水中的含量，本方法的线性范围为４．０－４０．０ｎｇＦｅ＾３＋／ｍｌ，相对标准偏差小于２．５％，标准加入回收率在９８．７％－１０１％之间，检测限为１．９２ｎｇＦｅ＾３＋／ｍｌ。对照实验结果表明，导数动力学法比一般非导数动力学法具有线关     

VOCl_3/Et_3Al_2Cl_3/CCl_4溶剂体系催化乙烯丙烯共聚

本文以VOCl_3/Et_3Al_2Cl_3为催化剂,在CCl_4溶剂中进行乙烯共聚反应。在聚合过程中,发生一异常的颜色突变现象。颜色突变后,体系催化聚合生成分子量很低的产物。从聚合物的结构表征及机理探讨表明:颜色突变后,体系产生了新的活性中心,催化机理发生了转变——由配位机理转变为阳离子机理。     

负载型催化剂制备的聚丙烯等规度分布

负载型Ziesler－Natta催化剂中存在许多活性中心［'3，为了解其本质，需对其各自产生的聚合物进行分离，以往采用的溶剂抽提法［'－'j只能将聚合物大致分级．最近，升温淋洗分级法（TREF）已被运用于聚丙烯的分级卜，'，其原理是根据聚合物的结晶度分级D'，影响聚丙烯结晶性的主要因素是等规度，而分子量到达一定程度后其影响较小，故通过TREF分级可得到聚丙烯的等规度分布．TREF法的淋洗温度可控，故分级效果较好．该法在分级前需对样品进行等温结晶处理，以消除抽提法由于样品未必充分结晶而带来的误差．本文用TREF法对不同催化…     

碳纤维微电极研究(Ⅺ)——利用温度效应测定电极反应的热力学和动力学参数

研究了温度对碳纤维微电极上伏安曲线的影响及温度与电极电位的关系,测定了电极反应的热力学参数.由电流与温度的关系测定了去极剂的扩散活化能E_(al)和D_o,利用微电极具有高速传质的特性,测定了常规电极上为可逆反应的电极反应标准速率常数(?),并通过(?)与温度的关系测定了电极反应的活化能.     

IMMOBILIZATION OF POTENTIALLY BIOACTIVE MOIETIES ONTO POLYETHER WITH POLY(ETHYLENE GLYCOL)-SULFONATE SPACER

A new reactive graft copolymer, poly(tetramthylene glycol) - graft-w-propyl sodiumsulfonate-poly(ethylene glycol) (PTMG-g-PEG-CH_2CH_2CH_2SO_3~-Na~+), was synthesizedby the cationic polymerization of a-w-bifunctional PEG macromonomer (O?CH_2—PEG——CH_2 CH_2 CH_2 SO_3 Na) and THF. The obtained copolymer exhibits the expected structureas indicated by the result of characterization. Two amino acids (L-arginine, L-tyrosine)were covalently attached to the copolymer after converting the sulfonate group to sulfonylchloride. So the new reactive graft copolymer (PTMG-g-PEG-CH_2CH_2CH_2SO_3~-Na~+) isexpected to be very useful in attachment of potentially bioactive moieties to polymer viaa hydrophilic PEG spacer.     

苯乙烯-马来酸酐自由基共聚反应 (Ⅰ)苯乙烯-马来酸酐电荷转移络合反应

电荷转移络合反应机理是研究苯乙烯－马来酸酐自由基交替共聚反应机理的关键。本文简述了苯乙烯－马来酸酐电荷转移络合反应的研究进展。     

~(13)C-NMR STUDY OF ETHYLENE-1-OCTENE COPOLYMERS

A ~(13)C-NMR method is presented for a quantitative determination of the respective monomercomposition and sequence distributions in ethylene-1-octene copolymers prepared with supportedtitanium/magnesium catalyst. On the basis of the sequence distributions, the ethylene-1-octenecopolymerization mechanism was studied. It was found that the observed sequence distributions inethylene-1-octene copolymers are satisfactorily predicted by the two-site model M/M,in whichthe copolymerization proceeds according to first-order Markovian statistics at the two differentsites.