sPS/PA6/SsPS-Zn塑料合金的研究

研究了磺化间规聚苯乙烯磺酸锌盐（SsPS-Zn)的增容作用以及sPS/PA6/SsPS-Zn三组分塑料合金的力学、热学性能和微观形态结构。结果表明：SsPS-Zn的加入明显地改善了sPS/PA6二组分合金的力学性能，在sPS/PA6/SsPS-Zn重量组成为80／20／5时，合金冲击强度最大，为14．2kJ/m^2。DMA和SEM结果表明，SsPS-Zn在合金中起到了降低微相尺寸和加强相间界面粘结的作用，可显著提高sPS和PA6两组分间的相容性，FTIR研究表明SsPS-Zn的磺酸锌基团和PA6的酰胺基之间存在相互作用。     

间规聚苯乙烯/尼龙6/磺化间规聚苯乙烯/蒙脱土纳米复合材料的研究

以磺化间规聚苯乙烯（SsPS)为增容剂，将间规聚苯乙烯（sPS)和尼龙6／改性蒙脱土纳米复合物（PA6－MTA）共混，得到综合性能优良的新型多组分聚合物／蒙脱土纳米复合材料（sPS/PA6/SsPS/MTA)。用DSC、DMA、WAXD及力学性能测试仪研究了纳米复合材料的结构与性能。TEM测定证明了蒙脱土在基体中的层厚分布为10－50nm。     

新型sPS/PA6/SsPS-H塑料合金的性能和形态结构

研究新型sPS PA6 SsPS H塑料合金的力学性能和微观形态结构 .间规聚苯乙烯 (sPS)的磺化产物磺化间规聚苯乙烯 (SsPS H)的加入明显地改善了sPS PA6(聚酰胺 6)二组分合金的力学性能 ,在sPS PA6 SsPS H重量组成为 80 2 0 5时 ,三组分合金的冲击强度最大 ,为 1 5 6kJ m2 ,约为纯sPS冲击强度的 3倍 DMA和SEM结果表明 ,SsPS H对sPS和PA6共混有良好的增容作用 ,它起到了降低合金的微相尺寸和加强相间界面粘结的作用 .此外 ,FTIR结果还表明SsPS H和PA6之间存在特殊相互作用 ,其作用方式是通过SsPS H的磺酸基将其质子转移给PA6酰胺基的氮     

新型sPS/PET/SsPS-Zn工程塑料合金的研究

熔融共混法制备了新型综合性能较好的间规聚苯乙烯 (sPS) 聚对苯二甲酸乙二醇酯 (PET) 磺化间规聚苯乙烯锌盐 (SsPS Zn)工程塑料合金 ,研究了合金结构与性能之间的关系 .加入SsPS Zn后 ,合金的力学性能先提高而后下降 ,当sPS PET SsPS Zn为 85 15 2 (质量比 )时 ,合金的综合力学性能较好 ,冲击强度达到 10 6kJ m2 ,为纯sPS的 2 5倍 ;加入SsPS Zn后 ,合金的耐热性提高 ;合金中sPS的熔点与纯sPS相同 ,而初始结晶温度和达到最大结晶速度时的温度均高于纯sPS ,且基本不受SsPS Zn用量的影响 .PET的熔点、初始结晶温度、达到最大结晶速率时的温度和结晶度均随SsPS Zn用量的增加而逐渐降低 ;DMA结果中所有合金均只呈现一个Tg,并且加入SsPS Zn后 ,Tg 和半峰宽都逐渐提高 ,常温下的储能模量在其用量为 2份时达到最大值 ;SEM观察到加入 2份SsPS Zn后 ,PET分散相的尺寸明显减小 ,继续增加其用量 ,PET分散相的尺寸反而有所增大和不均匀 ,并且合金的冲击断面由显著的层状结构转为相对平整     

双核单茂钛催化苯乙烯间规聚合反应

二十世纪八十年代,Ishihara等人首次使用钛/甲基铝氧烷(MAO)催化体系成功地制备了间规聚苯乙烯(sPS)[1].此后,由于sPS具有结晶速度快,熔点达270℃,赋予了sPS不同于一般聚苯乙烯的优良性能,因此研制新型的苯乙烯间规聚合催化剂成为国内外的研究热点之一.以往的研究主要集中于催化剂活性的提高,因为单核催化剂只是单一的活性中心,所以只能制备窄分子量分布(MWD)的sPS.近年来,为了提高sPS的加工性能和拓宽sPS的分子量分布,人们使用了不同的茂金属混合物[2,3]或者Z iegler-Natta催化剂的氢化物和单一的茂金属进行了诸多尝试[4,5].至今,…     

磺化间规聚苯乙烯的表征

间规聚苯乙烯(sPS)是一种新型结晶性工程塑料,熔点达270℃,具有结晶速度快、耐热性好、耐化学腐蚀性优良等特点,可广泛用于汽车、电子、机械等行业,极具开发意义,但是由于sPS脆性大,抗冲击性差,故通过化学改性在sPS的苯环上引入极性基团,用于制成共混合金与复合材料,是提高材料韧性,开拓sPS用途的重要途径。     

间规聚苯乙烯的改性研究

间规聚苯乙烯(sPS)问世以来,这种新的热塑性聚合物在不同领域的应用得到广泛关注。介绍了sPS的结构与性能,综述了其发展、改性及应用情况。     

sPS/PA6/蒙脱土纳米复合材料的制备与性能

讨论了间规聚苯乙烯 (sPS) 尼龙 6(PA6) 磺化间规聚苯乙烯 (SsPS H) 蒙脱土纳米复合材料的制备技术和新材料的结构与性能特征 .蒙脱土经层间改性处理后 (MTN) ,可分别将SsPS H和aPS(无规聚苯乙烯 )插入其纳米层间 ,制备出插层型纳米复合物MTN SsPS和MTN aPS .在sPS/PA6/SsPS H三组分共混体系中加入MTN SsPS或MTN aPS ,进行四组分熔融共混即可制备出sPS/PA6/SsPS H/蒙脱土纳米复合材料 .TEM测定证实了蒙脱土在基体中的层厚分布约为 5 0nm .此外 ,采用DSC、DMA、XRD及力学性能测试仪等现代分析方法对sPS/PA6/SsPS H/蒙脱土纳米复合材料的结构与性能进行了详细研究 .研究结果表明这种纳米复合材料具有优良的综合性能     

sPS/PET/SsPS-H共混体系的研究

以自制间规聚苯乙烯(sPS)功能化合成的磺化间规聚苯乙烯（SsPS-H)作相容剂,研究其对sPS/PET共混物微相结构与性能的影响,发现SsPS-H能够有效地改善二者的相容性,当sPS/PET/SsPS-H为85／15／2（重量比）时,冲击强度达到11．4kJ/m^2,为纯sPS的3倍,此时材料的弯曲强度为39．1MPa,下降约8％;DMA结果表明,随SsPS-H用量的增加,共混物的Tg逐渐提高;DSC分析结果表明,共混体系中sPS的熔点不受SsPS-H含量的影响,而PET的熔点在加入6份SpPS-H时明显降低。sPS在达到最大结晶速率的温度均随SsPS-H用量的增加先提而后下降。SEM观察到加入SsPS-H后,PET分散相的尺寸减小,且均匀程度增加,共混物室温下冲击断裂显著地由脆性转变为韧性,当加入6份SsPS-H后,冲击断裂又出现脆性。     

间规聚苯乙烯的化学改性

介绍了间规聚苯乙烯（sPS)的结构，特性和各种化学改性方法，包括在sPS侧链苯环上引入磺酸基，卤素等功能基因，在sPS分子链末端引入马来酸酐，丙烯酸酯等极性基因，与氢化丁二烯－苯乙烯热塑性弹性体（SEBS）形成接枝共聚物，及其与各类烯烃单体的共聚，对进一步拓宽sPs的应用领域具有重要意义。     

新型茂钛催化剂原位本体聚合法制备间规聚苯乙烯/蒙脱土纳米复合材料

采用多碳氨基酸对蒙脱土进行改性 ,得到改性蒙脱土 (MTN) ,并使其层间距扩大 ,在一定条件下用茂金属催化剂Cp Ti(O C6 H4 F) 3 进行苯乙烯原位聚合发现 ,在氨基酸改性的蒙脱土存在下 ,茂金属催化剂活性有所提高 ,能制得间规聚苯乙烯 (sPS) 蒙脱土纳米复合材料 ,考察了蒙脱土用量对配位聚合的影响及该复合材料的形态结构、热稳定性和结晶性能     

Synthesis of polar block grafted syndiotactic polystyrenes via a combination of iridium‐catalyzed activation of aromatic C?H bonds and atom transfer radical polymerization

A combination of iridium‐catalyzed C H activation/borylation and atom transfer radical polymerization (ATRP) was used to generate polar graft copolymers of syndiotactic polystyrene (sPS). The borylation at aromatic C H bonds of sPS and subsequent oxidation of boronate ester proceeded without negatively affecting the molecular weight properties and the tacticity of sPS. A macroinitiator suitable for ATRP could be synthesized by the esterification of 2‐bromo‐2‐methylpropionyl bromide and hydroxy‐functionalized sPS. The graft polymerizations of methyl methacrylate and tert‐butyl acrylate from the macroinitiator using ATRP afforded polar block grafted sPS materials, syndiotactic polystyrene‐graft‐poly(methyl methacrylate) (sPS‐g‐PMMA) and syndiotactic polystyrene‐graft‐poly(tert‐butyl acrylate) (sPS‐g‐PtBA). The latter was hydrolyzed to yield an amphiphilic graft copolymer, syndiotactic polystyrene‐graft‐poly(acrylic acid) (sPS‐g‐PAA). The structures of the copolymers were characterized by NMR and FTIR spectroscopies. Size exclusion chromatography and ¹H NMR spectroscopy were used to study any changes in the molecular weight properties from the parent polymer. A decrease in the hydrophobicity of the graft copolymers was confirmed by water contact angle measurements. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6655–6667, 2009     

Sorption of Pollutant Traces by Nanoporous Crystalline Aerogels: Visualization by a Dye

Summary: The influence of the crystalline structure on the pollutant sorption properties of high porosity syndiotactic polystyrene (sPS) aerogels has been made visible by using azulene, a blue dye, capable to form a clathrate phase with sPS. The bluish coloration observed for aerogels with the nanoporous δ-form and the absence of coloration for aerogels with the densely-packed γ-form clearly establish that the crystalline nanopores play a key role for the removal of pollutant traces from water or air.     

间规聚苯乙烯/等规聚丙烯/间规聚苯乙烯-b-聚(1-丁烯)共混体系相容性

间规聚苯乙烯(sPS)的改性主要是对其增韧改性,提高其力学性能.sPS的化学改性已有较多文献报道[1,2].     

Novel syndiotactic polystyrene/BaTiO3-graphite nanosheets three-phase composites with high dielectric permittivity

Novel three-phase composites were prepared by embedding graphite nanosheets (GNs) and BaTiO₃ nanoparticles into syndiotactic polystyrene (sPS) matrix via a solution blending and flocculation method. The dependences of electric and dielectric properties of the resultant sPS/BaTiO₃-GNs composites on volume fractions of GNs (f_GNs) and frequency were investigated. The percolation theory was employed to explain the electric and dielectric behavior of sPS/BaTiO₃-GNs composite. It was found that the sPS/BaTiO₃-GNs composite showed an obvious insulator-conductor transition with a much low percolation threshold of f_GNs = 1.44 vol%. The dielectric permittivity of sPS/BaTiO₃-GNs composite reached as high as 51.8 at 100 Hz at percolation threshold, which was about 18 and 7 times higher than that of pure sPS and sPS/BaTiO₃ composite, respectively.     

Hydrophilic functionalization of syndiotactic polystyrene via a combination of electrophilic bromination and Suzuki–Miyaura reaction

Postfunctionalization of high‐molecular‐weight syndiotactic polystyrene (sPS) was achieved via combination of electrophilic bromination at the para‐position of the polymer aromatic ring and subsequent Suzuki–Miyaura cross‐coupling reactions with functionalized phenylboronic acids. The concentration of brominated styrene repeating unit in sPS was conveniently controlled by changing the ratio of added bromine relative to the polymer repeating unit. Brominated sPS (8.5 mol %) was converted quantitatively to other polar functional groups via Suzuki–Miyaura cross‐coupling reactions with various functional group‐substituted phenylboronic acids. The surface properties of functionalized sPS were studied by measuring water contact angles. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4335–4343, 2010     

Application of Fluorescence Depolarization Method to Monitor Free Volume in Gels of Stereoregular Polystyrene

Summary: A fluorescence depolarization technique was applied to get the information on free volume among polymer chains in gel form. Four fluorescent molecules with different molecular sizes were doped throughout the gels of syndiotactic polystyrene (sPS) and isotactic polystyrene (iPS) physical gel system, and their fluorescence anisotropy values were examined in detail for a range of polymer concentrations. Consequently, the free volume among sPS chains in sPS/chloroform gels is as large as the size of molecules smaller than 1,5-dimethylnaphthalene and is consistent with that of the cavity size in the δ-empty crystalline form of sPS solids. The cause to produce δ-empty crystalline form of sPS solids and to form cocrystals between sPS and guest molecules is discussed by comparing the molar size of guest molecules with the free volume among sPS chains in gel form.     

Thermal properties and crystalline structure of syndiotactic polystyrene‐based miscible blends

This work examined the effect of the pre‐melting temperature (T_max) on the thermal properties and crystalline structure of four miscible syndiotactic polystyrene (sPS)‐based blends containing 80 wt % sPS. The counterparts for sPS included a high‐molecular‐weight atactic polystyrene [aPS(H)], a medium‐molecular‐weight atactic polystyrene [aPS(M)], a low‐molecular‐weight atactic polystyrene [aPS(L)], and a low‐molecular‐weight poly(styrene‐co‐α‐methyl styrene) [P(S‐co‐αMS)]. According to differential scanning calorimetry measurements, upon nonisothermal melt crystallization, the crystallization of sPS shifted to lower temperatures in the blends, and the shift followed this order of counterpart addition: P(S‐co‐αMS) > aPS(L) > aPS(M) > aPS(H). The change in T_max (from 285 to 315 °C) influenced the crystallization of sPS in the blends to different degrees, depending on the counterpart's molecular weight and cooling rate. The change in T_max also affected the complex melting behaviors of pure sPS and an sPS/aPS(H) blend, but it affected those of the other blends to a lesser extent. Microscopy investigations demonstrated that changing T_max slightly affected the blends' crystalline morphology, but it apparently altered that of pure sPS. Furthermore, the X‐ray diffraction results revealed that the α‐form sPS crystal content in the blends generally decreased with an increase in T_max, and it decreased with a decrease in the cooling rate as well. The blends showed a lower α‐form content than pure sPS; a counterpart of a lower molecular weight more effectively reduced the formation of α‐form crystals. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2798–2810, 2006