用环氧化苯乙烯-丁二烯-苯乙烯嵌段共聚物制备和表征离聚体

利用环氧化苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)的环氧基与顺丁烯二酸氢钾在相转移催化剂及二甲基苯胺存在下开环反应制得钾离聚体。研究了其反应条件,得到了环氧基的最大转化率达65％,并用红外光谱确定其为离聚体。     

顺丁烯二酸钾基(苯乙烯-丁二烯-苯乙烯)嵌段共聚物离聚体的力学性能及其应用

用环氧化(苯乙烯-丁二烯-苯乙烯)嵌段共聚物(SBS)开环反应合成了含顺丁烯二酸钾基的SBS离聚体,考察了离子基团不同含量对含顺丁烯二酸钾基的SBS离聚体力学性能的影响,研究了离聚体/聚丙烯(PP)共混物的力学性能和耐溶剂性能,以及离聚体对氯醇橡胶(CHR)/SBS共混物的增容效果。结果表明,该离聚体呈现热塑性弹性体行为;随着离子基团含量的增加,离聚体的拉伸强度及扯断伸长率增大,但当离子基团含量超过1.69mmol/g时,离聚体的力学性能又有所下降,离子基团最佳含量为1.23~1.69mmol/g;该离聚体与PP共混,在拉伸强度方面呈现协同效应;离聚体作为增容剂提高了SBS与CHR的相容性,当离聚体质量分数为3%时,力学性能达到最佳,共混物的耐溶剂性能也得到了改善。     

用环氧化苯乙烯-丁二烯-苯乙烯嵌段共聚物开环反应制备新型磷酸盐离聚体及其性能

研究了用环氧化苯乙烯-丁二烯-苯乙烯嵌段共聚物(ESBS)在相转移催化剂、开环催化剂存在下与Na2HPO4的水溶液发生开环反应,制得了磷酸盐离聚体。结果表明,在ESBS的浓度为0.14g/mL、Na2HPO4/环氧基(摩尔比)为1.8、Na3PO4/Na2HPO4(质量比)为0.6、溴化四乙基铵/ESBS(质量比)为0.05、N,N-二甲基苯胺/ESBS(质量比)为0.05以及聚合温度为75℃、反应时间为8h的条件下,反应转化率达32%。该离聚体具有很好的乳化性、一定的吸水性和耐油性,这些性质均与离子含量及离子电位有关。     

通过环氧化苯乙烯-丁二烯-苯乙烯嵌段共聚物与亚硫酸氢钠的开环反应制备磺化离聚体

用环氧化苯乙烯-丁二烯-苯乙烯嵌段共聚物（ESBS）在相转移催化剂、开环催化剂存在下与亚硫酸氢钠的水溶液进行开环反应制备了SBS磺化离聚体,用傅里叶变换红外光谱法对产物进行了表征。研究表明,当环氧基转化率达90％时,反应条件为ESBS的质量浓度0．12g／mL。NaHSO3／环氧基（摩尔比）1．8,促进剂／NaHSO3（质量比）0．36。四乙基澳化铵／ESBS（质量比）0．05,二甲基苯胺／ESBS（质量比）0．05,60℃,7h。     

用环氧化苯乙烯-丁二烯-苯乙烯嵌段共聚物制备季铵盐离聚体

用环氧化苯乙烯-丁二烯-苯乙烯嵌段共聚物的环氧基与叔胺盐酸盐在相转移催化剂存在下,通过开环反应制得了季铵盐离聚体,用过氯酸滴定法及核磁共振仪进行了表征。研究表明,该反应中环氧基的转化率可达到100％;反应产物为季铵盐离聚体,其在48h时的吸水率达到了115％。     

磷酸盐基(苯乙烯-丁二烯-苯乙烯)嵌段共聚物离聚体的结构、性能及应用

由环氧化的苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)与磷酸氢二钠通过开环反应制备了含磷酸二钠基的SBS离聚体(PSBS),研究了PSBS的形态结构、混炼胶力学性能的影响因素、PSBS/聚丙烯(PP)共混物的力学性能以及PSBS对SBS/氯醚橡胶(CHR)共混物的增容作用.结果表明,磷酸盐基SBS离聚体呈大小不一、形状不规则的离子微区;当硬脂酸锌用量为PSBS质量分数的10%、离子基团含量为0.95 mmol/g时,PSBS混炼胶的力学性能最佳,且呈现热塑性弹性体行为;PSBS与PP共混,其拉伸强度与组成呈现协同效应,且耐甲苯性提高;PSBS可作为SBS/CHR共混物的增容刺,其最佳质量分数为3%,离聚体的加入有助于改善共混物的耐油性和相客性.     

磺酸钠基苯乙烯-丁二烯-苯乙烯嵌段共聚物离聚体的力学性能及其应用

由环氧化苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)与NaHSO3开环反应合成了磺酸钠基SBS离聚体。研究了离聚体力学性能的影响因素、离聚体对SBS/氯醇橡胶(CHR)的增容作用、质量比对离聚体/聚丙烯(PP)共混物性能的影响。结果表明:硬脂酸锌能提高离聚体的力学性能;随着离聚体离子含量的增加,拉伸强度及扯断伸长率增加。加入少量离聚体,使离聚体/CHR共混物的力学性能提高,扫描电镜显示两者的相容性增加;离聚体与PP共混,在拉伸强度方面呈现协同效应。质量比各为1/1的离聚体增容SBS/CHR和离聚体/PP共混物的耐油性均较SBS大为改善。     

顺酐化苯乙烯-丁二烯-苯乙烯嵌段共聚物离聚体的制备及其结构和性能

在甲苯/环己烷混合溶剂体系中考察了顺酐化苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)的制备条件,得到马来酸酐/SBS/过氧化苯甲酰质量比为30/100/1、SBS质量浓度为0.10 g/mL、过氧化苯甲酰/甲苯引发液的滴加时间为10 min及75 ℃下反应4 h的较为理想的反应条件.在此条件下既可以避免凝胶的生成,又可获得较高的接枝率(6.87%).所得顺酐化SBS经氢氧化钠溶液中和后生成钠离聚体,傅里叶变换红外光谱分析证实接枝反应和离聚体的合成均得到预期的产物.差示扫描量热分析结果表明离子化微区的存在使得离聚体在高温段有1个玻璃化转变温度.离聚体的拉伸强度、搭接剪切强度和乳化性能均随顺酐化程度的提高而改善.     

两亲性聚氧乙烯接枝(苯乙烯-丁二烯-苯乙烯)三嵌段共聚物

通过环氧化(苯乙烯-丁二烯-苯乙烯)三嵌段共聚物(SBS)与端羧基甲氧基聚乙二醇的开环反应,合成了带聚氧乙烯支链的两亲性SBS接枝物,通过红外光谱及核磁共振氢谱进行了表征,并确定了该两亲性聚合物具有良好的乳化性质及相转移催化性质.     

氢化苯乙烯-丁二烯-苯乙烯嵌段共聚物研究进展

概述了氢化苯乙烯-丁二烯-苯乙烯嵌段共聚物(SEBS)国内外生产状况,介绍了SEBS生产工艺技术及其加氢催化剂的开发进展,提出应加强SEBS的改性及应用技术开发,在国内尽快实现SEBS的规模化工业生产。     

含磷酸钠基的SBS两亲离聚体的合成、表征及性质

环氧化SBS在甲苯中与磷酸氢二钠水溶液,以N,N-二甲基苯胺及四乙基溴化铵为催化剂,通过开环反应合成了含磷酸二钠基的两亲性SBS离聚体。离聚体采用FTIR进行表征。研究了开环反应条件及该离聚体的乳化性、吸水性、耐油性和稀溶液粘度。结果表明开环率可以达到32%,该离聚体具有很好的乳化性、明显的吸水性和耐油性,其乳化性、吸水性、耐油性及稀溶液粘度随离子含量增加而增大,随一价阳离子的离子电位增加而增加。     

Semifluorinated ABA triblock copolymers: Synthesis,characterization, and amphiphilic properties

In this study a series of novel semifluorinated ABA triblock copolymers with different fluorinated segment lengths and different fluorocarbon side‐chain structures were synthesized via atom transfer radical polymerization (ATRP) and macroinitiator techniques. The macroinitiator, telechelic bromine terminated polystyrene, was obtained from bulk ATRP of styrene with α,α′‐dibromo‐p‐xylene as the initiator and cuprous bromide/α,α′‐bispyridine complex as the catalyst. The polymerization reactions of 2‐[(perfluorononenyl)oxy] ethyl methacrylate and ethylene glycol monomethacrylate monoperfluorooctanoate were initiated by the macroinitiator in the presence of additional catalyst. The characterization of the block copolymers was performed by gel permeation chromatography, ¹H‐NMR spectroscopy, and differential scanning calorimetry. The surface activities of the block copolymers in toluene were investigated with the Wilhelmy plate method. The solid surface energy of the block copolymers was determined by measurement of the contact angles. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2625–2633, 2002     

Ultrasonic studies of styrene-butadiene-styrene triblock copolymers

Ultrasonic measurements covering the frequency range 5–1000 MHz are reported on solid styrene-butadiene-styrene triblock copolymers and their solutions in toluene and cyclohexane. In the solid, two distinct relaxation processes were observed, corresponding to the glass transitions of the polystyrene and polybutadiene phases. Two distinct processes were observed also in the swollen solid, the relaxation peaks being shifted to lower temperatures with plasticization of the polymer by the solvent. Comparison of the changes observed with those detected in a similar mixture of the corresponding homopolymers confirms the importance of phase separation in the swollen copolymer. An increase in the high frequency attenuation of semi-dilute solutions can be associated with scattering of the sound wave by micelle structures. The temperature-concentration locus at which this scattering is first observed correlates with other observations of microphase separation in triblock copolymers. At these concentrations, the low frequency relaxation curves deviate from extrapolation from dilute solutions data indicative of significant polymer-polymer entanglement interaction.     

不同金属离子中和的新型硫酸盐基顺丁橡胶离聚体的合成、表征与性质

用环氧化顺丁橡胶在二氯乙烷中与硫酸氢钾、硫酸氢钠或硫酸氢锂水溶液以N,N-二甲基苯胺和四乙基溴化铵为催化剂进行反应,合成了新型的含硫酸钾、硫酸钠或硫酸锂基的顺丁橡胶离聚体,还用钾离聚体与醋酸镁、钙、钡、锌或铅溶液反应并洗涤,生成相应的离聚体。离聚体经纯化,用红外光谱（FTIR）及透射电镜表征,确定了硫酸盐基离子及其微区的存在。研究了开环反应的一些条件,结果表明,开环率可达到36％,该离聚体具有相当好的乳化性、一定的吸水性及耐油性,其吸水率和乳化性随离子电位的增加而增大,一价离子的吸水率及乳化体积比二价离子的大;稀溶液粘度随离子电位的增加而增大,二价离子的粘度比一价离子的大;其作为增容剂能增加SBS和氯醇橡胶的相容性。     

带聚氧乙烯支链的SBS两亲接枝共聚物的合成、表征及性能

在甲苯中,以N,N-二甲基苯胺为催化剂,用环氧化苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)与端顺丁烯二酸基聚乙二醇甲醚合成了带聚氧乙烯支链的SBS.粗产物经纯化后用傅里叶变换红外光谱和氢核磁共振仪进行了表征.研究了开环反应的条件,结果表明在适宜条件下产物开环率可达46.5%.接枝共聚物呈现良好的乳化性能、相转移催化性能和一定的吸水性和耐油性;其作为增容剂能增强SBS与氯醇橡胶的相容性,并用扫描电镜给予了佐证.     

Preparation,properties, and mathematical modeling of microparticle drug delivery systems based on biodegradable amphiphilic triblock copolymers

A series of biodegradable amphiphilic A‐B‐A type triblock copolymers P(BLA‐PEG‐BLA), composed of hydrophilic poly(ethylene glycol) (PEG) as a middle block component (B) and hydrophobic poly(β‐benzyl‐L ‐aspartate) as outer polypeptide block components (A), were synthesized by copolymerization of β‐benzyl‐L ‐aspartate N‐carboxy anhydride (BLA‐NCA) and the diaminated PEG with the primary amino groups capped at both ends. These P(BLA‐PEG‐BLA) copolymers were characterized by ¹H‐NMR, DSC, and GPC. The triblock copolymers were used to prepare three kinds of drug delivery systems including Norfloxacin (INN)‐incorporated P(BLA‐PEG‐BLA) microparticles and tablets. The morphologies of the microparticles were characterized by SEM. The in vitro release properties of the microparticles and tablets in PBS were also evaluated. A mathematical model, which incorporates a linear first‐order dissolution term and the transient Fickian diffusion equation, was developed to account for the kinetics of drug release from the INN‐incorporated P(BLA‐PEG‐BLA) microparticles. The results indicated that the overall release process was well controlled by both drug dissolution and diffusion. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3869–3873, 2004     

Synthesis,characterization and properties of amphiphilic butadiene-oxyethylene multiblock copolymers

Butadiene-oxyethylene multiblock copolymers were synthesized via coupling reaction of telechelic α,ω-dihydroxypolybutadiene (PB) and poly(ethylene glycol) with tolylene-2,4-diisocyanate. The poly(oxyethylene) (PEO) content of the purified copolymer was determined by elemental analysis and the structural parameters were calculated from number-average molecular weights of the purified copolymer, determined by membrane osmometry, and those of the prepolymers, determined by vapor pressure osmometry. The total number of blocks varied from 60 to 100. Transmission electron microscopy showed the existence of multiphases in the copolymer. Wide angle X-ray diffraction indicated that the crystallinity increased from 0 to 50% with increasing weight ratio of PEO/PB. These multiblock copolymers exhibit excellent emulsifying properties, as compared to the multiblock copolymers or graft copolymer of oxyethylene and styrene. Only 0.1 g of polymer was needed to make 100 mL of a water/toluene (9:1, w/w) mixture form an emulsion completely. When the weight ratio of water/toluene was changed from 9:1 to 7:3 or the molecular weight of PEG from 6000 to 2000, the oil-in-water type emulsion was changed to water-in-oil type. The copolymers also showed a good phase transfer catalytic effect when applied to the Williamson reaction. Conversion of potassium phenolate into butyl phenolate reached over 95% when the multiblock copolymer containing 3 mmol of PEO was used for 1 g potassium phenolate, whereas no reaction occurred without using the multiblock copolymer at 90°C for 4 h.     

极性化苯乙烯-丁二烯-苯乙烯三嵌段共聚物的磺化改性及其纳米复合材料的制备

以浓硫酸和乙酸酐制得的乙酰硫酸酯为磺化剂,对极性化苯乙烯-丁二烯-苯乙烯三嵌段共聚物(PSBS)进行磺化改性,采用红外光谱表征了磺化PSBS(SPSBS),通过测定硫元素含量考察了磺化条件,并用熔融插层法制备了SPSBS/有机蒙脱土(OMMT)纳米复合材料,研究了复合材料的插层结构和拉伸性能。结果表明,在丙酮/环己烷为混合溶剂(丙酮体积分数为10%)、PSBS质量浓度为0.10～0.15 g/mL、硫酸/PSBS(质量比)为8.5/100、乙酸酐/硫酸(摩尔比)为1.69、反应温度为25℃、反应时间为15～40 min的条件下,PSBS可温和地进行磺化反应制得SPSBS,且反应过程中无凝胶产生;在SPSBS/OMMT纳米复合材料中,SPSBS插层进入OMMT片层间,且插层效果优于PSBS和苯乙烯-丁二烯-苯乙烯三嵌段共聚物(SBS);随着磺化度的增加,SPSBS的插层效果越好;SPSBS的拉伸性能优于PSBS和SBS,SPSBS/OMMT纳米复合材料的拉伸性能也优于PSBS/OMMT和SBS/OMMT纳米复合材料,且随着磺化度的增加,SPSBS/OMMT纳米复合材料的拉伸性能逐渐提高。