Compatibility and thermal properties of poly(acrylonitrile–butadiene–styrene) copolymer blends with poly(methyl methacrylate) and poly(styrene‐co‐acrylonitrile)

The mechanical and heat‐resistant properties of acrylonitrile–butadiene–styrene (ABS) binary and ternary blends were investigated. The relationship of compatibility and properties was discussed. The results show that poly(methyl methacrylate) (PMMA) and styrene–maleic anhydride (SMA) can improve the thermal properties of conventional ABS. The Izod impact property of ABS/PMMA blends increases significantly with the addition of PMMA, whereas that of ABS/SMA blends decreases significantly with the addition of SMA. Blends mixed with high‐viscosity PMMA are characterized by higher heat‐distortion temperature (HDT), and their heat resistance is similar to that of blends mixed with SMA. For high‐viscosity PMMA, from 10 to 20%, it is clear that blends appear at the brittle–ductile transition, which is related to the compatibility of the two phases. TEM micrographs show low‐content and high‐viscosity PMMA in large, abnormally shaped forms in the matrix. Compatibility between PMMA and ABS is dependent on both the amount and the viscosity of PMMA. When the amount of high‐viscosity PMMA varied from 10 to 20 wt %, the morphology of the ABS binary blends varied from poor to satisfactory compatibility. As the viscosity of PMMA decreases, the critical amount of PMMA needed for the compatibility of the two phases also decreases. SMA, as a compatibilizer, improved the interfacial adhesiveness of ABS and PMMA, which results in PMMA having good dispersion in the matrix. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2652–2660, 2002     

Gel chromatographic investigation of p-benzoquinone and styrene products copolymerized in the presence of BF3·OEt2

The molecular weight distribution of copolymers of p-benzoquinone and styrene was studied by g.p.c.. It was shown that the products synthesized have low molecular weights and narrow MWD. p-Benzoquinone was found to be a copolymer macromolecule regulator.     

苯乙烯的生产与市场分析

分析了国内外苯乙烯单体 (SM)的生产、供需情况及工艺进展。 2 0 0 2年全球苯乙烯单体 (SM)生产能力和需求分别为2 380万t/a和 2 1 0 0万t,预计到 2 0 0 5年全球SM生产能力将达到 2 763万t/a。 2 0 0 1年我国SM主要生产企业有 1 6家 ,总生产能力为 1 0 2万t/a ,表观消费量为 2 2 7 75万t,预计到 2 0 0 5年生产能力将达到 2 50万t/a ,表观消费量达到 396万t,需大量进口     

低苯乙烯散发不饱和聚酯树脂研究

用单官能团醇对不饱和聚酯树脂改性，合成了苯乙烯质量分数为30％和W01树脂，对W01树脂的挥发性和反应性进行了测定，研究了成膜助剂对01树脂性能的影响，并与通用型191树脂和一种亚克力板层间粘合用不饱和聚酯树脂进行了比较；指出结合成膜助剂的W01树脂进一步降低苯乙烯的散发。     

Preparation of micron‐size monodispersed PS/P(St/MAA) microspheres by seeded dispersion polymerization

Uniform polystyrene (PSt) particles with the size of 1.9 μm were first prepared via dispersion polymerization, and then used as the seeds in a second‐stage dispersion copolymerization of styrene (St) and methacrylic acid (MAA) to produce carboxyl‐carrying microspheres. The PSt seed particles were swollen by monomer mixture of St and MAA, including an oil‐soluble initiator 2,2′‐azobisiso‐butyronitrile (AIBN), before polymerization. Finally, uniform PS/P(St/MAA) (polydispersity index, PDI = 1.02) microspheres with the size of 2.2 μm were obtained. The average particle size and size distribution of the final microspheres were investigated. MAA contents between 54 and 97 mg/g were detected from the PS/P(St/MAA) particles produced under different conditions. Dispersion medium has great influence on the kinetics of polymerization, due to its effect on the partitioning of monomers, solvents, and initiator in the particle phase, probably as well as on the conformation of the dispersion agent on the surface of the particles. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3586–3591, 2006     

苯乙烯-马来酸酐交替共聚的合成研究

本实验以偶氮二异丁腈(AIBN)为引发剂,甲苯为溶剂,采用溶液沉淀聚合工艺合成了苯乙烯-马来酸酐共聚物,并详细考察了单体配比、单体浓度对聚合反应的产率和分子量的影响,对比了链转移剂对聚合产物分子量的影响.进一步通过红外,聚合物粘均分子量测定,对共聚物进行表征.     

聚合松香HEMA酯化物与苯乙烯的共聚研究

以聚合松香(PR)与甲基丙烯酸-β-羟乙酯(HEMA)的酯化物(PRH)为单体,采用自由基溶液聚合方法制备了PRH与苯乙烯(St)的共聚物(PRHS)。探讨了单体比例、反应温度、引发剂用量和反应时间对共聚反应的影响。用红外光谱、热重分析和差示扫描量热分析对产物的结构、热稳定性和玻璃化转变温度进行了测试表征。结果表明:成功合成了酯化物PRH与St的共聚物PRHS;共聚物的热稳定性高于酯化物,苯乙烯用量越多,共聚物热稳定性和玻璃化转变温度越高;PRH与St共聚较佳的反应条件为:mPRH∶mSt=1∶2;反应温度为110℃;m(引发剂)∶m(单体)=1%;反应时间为8 h,在此条件下,产率达70.14%。     

蓖麻油-马来酸酐-苯乙烯双功能润滑油添加剂的合成

传统石油基润滑油添加剂对环境的不利影响,使可生物降解的植物油基润滑油添加剂成为研究热点。以蓖麻油(CO)、马来酸酐(MAH)、苯乙烯(ST)为原料,偶氮二异丁腈(AIBN)为引发剂,甲苯为溶剂,合成了蓖麻油-马来酸酐-苯乙烯共聚物(PCMAS)。通过红外光谱(FT-IR)、核磁共振氢谱(¹H NMR)表征了蓖麻油-马来酸酐-苯乙烯共聚物的结构,采用凝胶渗透色谱(GPC)测定了聚合物的相对分子质量及其多分散性指数,采用热重分析研究了聚合物的热稳定性,并对聚合物作为润滑油降凝剂和黏度指数改进剂的性能进行了评价。结果表明：当单体质量比m(CO)∶m(MAH)∶m(ST)=1.0∶0.2∶1.2、引发剂AIBN含量占总单体的0.5%(质量分数)、反应时间4 h、反应温度90℃时,共聚物收率为68.39%,其数均相对分子质量为0.348×10⁵,多分散性指数为4.77。将蓖麻油-马来酸酐-苯乙烯共聚物添加到润滑油馏分(350～395℃)中,可降低润滑油的凝点,并提高其黏度指数。蓖麻油-马来酸酐-苯乙烯共聚物可作为一种具有降凝增黏双重功能的润滑油添加剂。     

高抗冲聚苯乙烯粒子发灰原因分析及对策

针对高抗冲聚苯乙烯（HIPS）生产过程中出现的粒子发灰现象,从原料、聚合和脱挥单元分析了原因,并采取了相应对策。结果表明:原料苯乙烯的含氧储存环境、聚丁二烯橡胶（BR）中挥发分及氯离子含量高是导致产品粒子发灰的主要原因;将苯乙烯存储由有氧环境改为氮气环境,严格控制 BR 中挥发分质量分数小于 0.5%,且优选线型低顺式BR,可有效降低 HIPS 产品粒子发灰的几率。     

工艺参数对选择性激光烧结PS/SBS/纳米CaCO3制件弯曲强度影响

针对聚苯乙烯(PS)粉末选择性激光烧结(SLS)成型件强度较低的问题,采用机械混合法制备了PS/苯乙烯–丁二烯–苯乙烯嵌段共聚物(SBS)/纳米CaCO₃复合粉末,通过单因素实验分析了SLS工艺参数对成型件弯曲强度的影响,并通过正交试验和极差分析获得了最优工艺参数组合。实验结果表明,烧结件的弯曲强度随着激光功率的增大而升高,随着扫描速度、扫描间距和分层厚度的增大而降低;激光功率对PS/SBS/纳米CaCO₃复合粉末烧结件弯曲强度的影响最大,分层厚度对弯曲强度的影响最小,扫描速度和扫描间距的影响介于两者之间;最佳工艺参数组合为:激光功率27 W,扫描速度1300 mm/s,扫描间距0.24 mm,单层厚度0.22 mm。在此工艺参数组合下PS/SBS/纳米CaCO₃复合粉末烧结件的弯曲强度为13.38 MPa;改性纳米CaCO₃与PS和SBS的相容性较好,能有效起到增强的作用。