苯乙烯-马来酸酐共聚物中酸酐含量测定方法研究

苯乙烯-马来酸酐共聚物（SMA）分子结构中含有酸酐官能团,易于化学改性得到新型功能高分子,在生物以及化学方面均表现出优异特性,而酸酐含量是影响其性能的重要因素,因此必须准确分析共聚物中酸酐含量。本文首先对SMA水溶液进行pH值滴定,确定了SMA在pH值突跃范围内以一元羧基／一元羧酸钠的形式存在,利用微商法确定该范围内pH滴定终点,建立了一种简便、快速确定酸酐含量的pH值滴定方法,并经元素分析验证了该方法测定结果的准确性。     

磺化苯乙烯-马来酸酐共聚物

磺化苯乙烯-马来酸酐共聚物是由苯乙烯-马来酸酐共聚物直接磺化并中和成钠盐制备。由于它分子中含有很多磺酸及羧酸负离子,因此,是一很好的阴离子聚电解质,被广泛用于泥浆稀释剂、水泥添加剂和皮革鞣剂等。     

苯乙烯-马来酸酐共聚物的核磁共振分析

利用^1H NMR、^13C NMR及DEPT(无畸变极化转移增强)核磁共振技术研究了苯乙烯-马来酸酐共聚物(SMA)的序列结构和组成，并比较了几种核磁共振实验技术对分析SMA结果的准确性；实验表明^1H NMR是分析组成的简单、快速而有效的方法，DEPT谱进行序列结构计算准确度较高。     

热重法测定高马来酸酐含量苯乙烯-马来酸酐共聚物的组成

高马来酸酐含量苯乙烯-马来酸酐共聚物(SMA)是一种具有优良耐热性、刚性和尺寸稳定性的新型高分子材料.由于SMA分子中含有极性很强、反应活性很高的酸酐官能团,所以它被广泛应用于涂料、粘合剂的改性剂、地板抛光的乳化剂、复合材料和颜料的分散剂、水处理剂等领域[1-5].     

苯乙烯/马来酸酐共聚物修饰碳纳米管的研究

利用羟基碳纳米管上的羟基与马来酸酐之间的简单反应, 在碳纳米管上引入双键, 进一步引发苯乙烯聚合, 在碳纳米管表面接枝苯乙烯马来酸酐共聚物, 同时采用羟基碳纳米管与苯乙烯马来酸酐共聚物直接反应也在碳纳米管的表面引入了苯乙烯马来酸酐共聚物. 经IR, Raman, TG和TEM测定, 证明了碳纳米管与苯乙烯马来酸酐共聚物之间为化学键连接关系.     

苯乙烯/马来酸酐共聚物氢键复合物的合成与表征

以４－苯乙烯基吡啶（４ＳＺ）为质子受体，准链链含苯甲酸的苯乙烯／马来酸单楷共聚物（ＭＥ－ＳＭＡ）为质子供体，四氢呋喃为溶剂，制备高分子氢链复合物。ＤＳＣ和ＰＯＭ的结果表明该氢链复合物在１４６￣２０４℃呈现向列相液晶态。ＩＲ结果证实了羧基和吡啶环的分子间氢键代替了羧基间的分子间氢链。     

苯乙烯马来酸酐共聚物化学改性研究进展

苯乙烯-马来酸酐共聚物具有优异的乳化、成膜、增稠等特性,是一种重要的功能化聚合物.从酯化、胺化、苯环接枝、带上电荷、引入功能性基团和引入第三单体等方面对于苯乙烯-马来酸酐共聚物化学改性进行了全面的总结,简评了各种化学改性的方法及改性共聚物的优点,报道了化学改性方法近年来出现的新进展.     

苯乙烯-马来酸酐共聚物的生物降解性研究

合成了一系列苯乙烯．马来酸酐共聚物(SMA)。并对共聚物的结构进行了表征。用土埋法和CO2释放法研究了共聚物的生物降解性。探讨了分子量、组成、环境等因素对生物降解性的影响,发现共聚物的分子量降低。降解率增大;共聚物中马来酸酐含量提高。降解率增大;适宜的环境有利于生物降解。     

苯乙烯-马来酸酐共聚物及其水解产物的结构与玻璃化温度的定量关系

采用示差扫描量热(DSC)法测定了苯乙烯-马来酸酐共聚物(SMA)及其水解产物(HSMA)的玻璃化转变温度(Tg).以Fox-Flory公式结合基团贡献法和改进的Couchman方程,对SMA和HSMA的Tg与其结构的关系进行了定量研究,理论计算结果与实验值吻合较好,表明提出的方程能适合SMA和HSMA两类聚合物的Tg估算.     

Fe-Al络合催化苯乙烯-马来酸酐交替共聚

应用Ｆｅ（ａｃａｃ）３ Ａｌ（ｉ Ｂｕ）３（ａｃａｃ＝乙酰丙酮）催化苯乙烯 马来酸酐共聚,制得富于交替的白色粉末共聚物．共聚反应动力学研究表明,共聚反应与单体浓度呈一级关系,表观活化能为４８６ｋＪ／ｍｏｌ．     

Studies of photochemical transformations in polystyrene and styrene-maleic anhydride copolymer

Thin films of polystyrene (PS) and styrene-maleic anhydride copolymer (St-MAn) were exposed to monochromatic UV radiation (254 nm) for varied time intervals. The course of photochemical transformations was monitored by absorption spectroscopy (FT-IR, UV-vis) and thermogravimetry, which were also applied for the estimation of the thermal stability of samples studied. The changes of surface properties were monitored by contact angle measurements.Changes in chemical structure were found in irradiated films (inside and at the surface). The efficiency of photooxidative degradation in St-MAn copolymer was slightly lower than that in PS homopolymer but photo-crosslinking and chromophore formation were enhanced. An increase of hydrophilicity and oxidation degree in UV-irradiated samples was accompanied by destruction processes. The thermal stability of St-MAn was lower in comparison to polystyrene alone.The mechanism of photochemical reactions in the copolymer is proposed.     

Environmentally degradable LLDPE/esterified styrene-maleic anhydride (ESMA) blends

LLDPE was blended with esterified styrene-maleic anhydride (ESMA) to improve the environmental degradation characteristics of LLDPE. ESMA was synthesized by esterifying styrene maleic anhydride (SMA) with n-decanol. LLDPE was blended with ESMA (EDP blends) and SMA separately in a single screw extruder by melt mixing. Composition of ESMA was varied from 20 to 40 wt% in the blends. LLDPE grafted with glycidyl methacrylate (LLDPE-g-GMA) was used as compatibilizer to improve the compatibility. Scanning electron photomicrograph (SEM) of cryofractured impact specimens showed significant reduction in domain size and uniform distribution of ESMA in LLDPE matrix in presence of compatibilizer in 70/30 blends. Environmental degradability was assessed by subjecting the films to soil burial test and exposure to buffer solution of different pH. Environmental degradation was followed by measuring the periodic change in weight of the blend samples. Films were exposed to accelerated and natural weathering and photodegradation was assessed by noting the embrittlement time of the film. Films of compatibilized blends fragmented at a faster rate than the films of uncompatibilized blend. Carbonyl index of films subjected to natural weathering was also found to be higher than that for the virgin LLDPE films.     

Synthesis of divinylbenzene–maleic anhydride microspheres using precipitation polymerization

Narrow disperse micron-range divinylbenzene-maleic anhydride microspheres have been prepared in near quantitative yields using precipitation polymerization. A variety of solvents were investigated for use as the reaction medium with a 40:60 mixture of methyl ethyl ketone and heptane providing the best results. The effects of solvent composition on particle size and morphology and monomer loading effects were also investigated. Particle size decreased with increasing solvency (increasing MEK fraction) while increases in monomer loading caused larger particle sizes. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2223–2227, 1998     

Living radical copolymerization of styrene/maleic anhydride

Styrene/maleic anhydride (MA) copolymerization was carried out using benzoyl peroxide (BPO) and 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO). Styrene/MA copolymerization proceeded faster and yielded higher molecular weight products compared to styrene homopolymerization. When styrene/MA copolymerization was approximated to follow the first‐order kinetics, the apparent activation energy appeared to be lower than that corresponding to styrene homopolymerization. Molecular weight of products from isothermal copolymerization of styrene/MA increased linearly with the conversion. However products from the copolymerization at different temperatures had molecular weight deviating from the linear relationship indicating that the copolymerization did not follow the perfect living polymerization characteristics. During the copolymerization, MA was preferentially consumed by styrene/MA random copolymerization and then polymerization of practically pure styrene continued to produce copolymers with styrene‐co‐MA block and styrene‐rich block. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2239–2244, 2000     

New potentially environmentally friendly copolymer of styrene and maleic acid—castor oil monoester

The maleic acid‐castor oil monoester (MACO) was synthesized and was used as monomer to synthesize a new potentially environmentally friendly copolymer of styrene and MACO (poly‐St/MACO) by suspension polymerization. Under the appropriate conditions, the poly‐St/MACO with yield of 81%, number average molecular weight of 44100 g/mol, and molecular weight distribution of 1.5 could be obtained. The chemical structures of the MACO and resulting copolymer were confirmed by Mass Spectrometry Infrared Spectroscopy and Nuclear Magnetic Resonance Spectroscopy H[1]. The results of thermogravimetric analysis and biodegradation test showed the poly‐St/MACO can be used as a new potentially environmentally friendly material with excellent thermal stability. Copyright © 2011 John Wiley & Sons, Ltd.     

Radical alternating copolymerization: A strategy for hyperbranched materials

Novel hyperbranched polymers were synthesized in a high yield without gelation through the free‐radical alternating copolymerization of an AB/B′ (allyloxy maleic acid/maleic anhydride) system, in which group B and monomer B′ both could only alternately polymerize with group A. The arm number of the produced highly branched polymers was equal to the product of the linear chain length and the probability of pendent B groups being growing centers. The molecular weight of these novel hyperbranched polymers increased with increasing initiator concentration and prolonged polymerization times. The AB/B′ system, used as described, provides a new general methodology for highly branched and functional polymers. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3074–3085, 2000     

Acrylonitrile–maleic anhydride copolymer membrane (II): effects of post‐treatment1

The effects of post‐treatment (including thermal treatment and base treatment) on the structure and performance of acrylonitrile–maleic anhydride (AN‐MA) copolymer membrane were investigated. The water flux decreased gradually (except the deviations when the temperature of thermal treatment was 50 °C or the time of thermal treatment was 50 min but rejection of bovine serum albumin increased slowly with increasing temperature or prolonging the time of thermal treatment. “The swelling effect of water in network” was proposed to explain the deviations. AN‐MA copolymer membrane is not resistant to a base. However, the performance of the membrane can be adjusted by treatment with a dilute base solution. Copyright © 2000 John Wiley & Sons, Ltd.