提高聚合物共混相容性的反应性聚合物

反应性聚合物作为聚合物共混的增容剂受到越来越广泛的重视。本文论述了该类反应性聚合物的制备，分类及研究开发现状，并结合实例讨论了其增容作用效果。     

聚烯烃／极性聚合物界面的分子状态

为了克服高分子共混物界面不易表征的缺点，提出用溶剂选择性溶解方法使界面暴露．结合Ｘ－射线光电子能谱（ＸＰＳ）表征手段，研究了官能化聚合物，接枝型共聚物及带有反应性基团的聚合物作为共混物增容剂时在界面区域的分子状态．实验结果表明，作增容剂时，官能化聚合物在界面区内采取最有利的分子构象，充分发挥增容作用；接枝型共聚物主链、侧链向相应本体聚合物内扩散；而带有反应性基团的聚合物与某个本体聚合物发生反应之前存在反应基团在界面富集的过程     

离子聚合物在Nylon－1010／PP共混物中的增容作用

离子聚合物在Ｎｙｌｏｎ－１０１０／ＰＰ共混物中的增容作用曲桂杰，刘景江（中国科学院长春应用化学研究所长春１３００２２）关键词聚丙烯，Ｎｙｌｏｎ－１０１０，离子聚合物，增容选择离子聚合物作为高聚物共混的增容剂，通过离子间的相互作用可达到增容效果［１］。...     

共聚物在聚合物共混体系中的增容作用Ⅱ.接枝共聚物和无规共聚物

在不相容的聚合物共混体系中加入共聚物作为增容剂可以有效地改善两相间的界面状况，得到力学性能优良的合金材料。本文主要讨论接枝共聚物和无规共聚物在聚合物共混体系中的增容作用和增容机理。     

几种典型固体聚合物体系的~（13）C自旋－晶格弛豫特性

用固体高分辨ＮＭＲ系统地研究了几种典型的均聚物，共聚物，聚合物共混物以及用接枝共聚物增容的不相容聚合物共混体系的１３Ｃ自旋－晶格弛豫特性。研究结果表明：１３Ｃ自旋－晶格弛豫时间（Ｔ１（Ｃ））是表征固体聚合物体系的很有用参数，它能提供有关本体聚合物微观形态结构的信息，并可望建立聚合物的微观结构与宏观性能的关系，它不仅能准确无误地反映共混体系中可能存在的各种相互作用，而且能定性地给出相互作用的大小和准确地指明相互作用产生的位置，因而为揭示共混体系的相容机理提供了最直接的证据，另外Ｔ１（Ｃ）还能给出增容剂对不相容共混体系的增容作用和增容机制的直接实验证据     

共聚物在聚合物共混体系中的增容作用I.嵌段共聚物

随着高分子合金领域的研究发展，以共聚物作为增容剂对不相容的聚合物共混体系进行改性已得到了广泛的研究和应用。本文分为两篇，分别介绍利用嵌段共聚物、接枝共聚物和无规共聚物所做的增容改性研究。本篇着重讨论嵌段共聚物(包括两嵌段和三嵌段以及多嵌段共聚物)在聚合物共混体系中的增容作用和增容机理。     

纳米SiO_2/聚丙烯复合材料的反应性增容

利用反应性增容技术制备了纳米二氧化硅/聚丙烯复合材料.首先探讨了将甲基丙烯酸缩水甘油酯-丙烯酸丁酯共聚物接枝到纳米二氧化硅粒子表面进行改性的各种影响因素,然后将接枝改性纳米二氧化硅与聚丙烯以及作为反应性增容剂的氨基化聚丙烯共混.结果表明,改性粒子上的环氧基与氨基化聚丙烯上的氨基之间的化学反应大大增强了复合材料的界面作用,从而在粒子含量很低时明显提高了聚丙烯的拉伸强度、模量和冲击强度.     

PS-b-PMMA对PVC/SBS共混体系界面结构的影响

在两种不相容的聚合物组成的共混体系中加入增容剂，可以显著提高共混体系的力学性能．目前的理论解释是嵌段共聚物在不相容的聚合物间形成界面层，通过降低组分间的界面张力、增强界面粘接力达到增容目的［‘－‘1．但是这一假设缺乏直接的实验证据．本文利用透射电子显微镜，     

聚合物共混物相容性的研究进展

相容性聚合物共混物由于其优异的复合性能已成为新材料的主要研究方向。但许多共混物是互不相容的 ,因此必须改善它们的相容性。文章综述了聚合物共混物相容性研究的现状与发展 ,介绍了各种增容方法及其应用     

几种反应型相容剂及其在聚合物共混改性中的应用

反应型增容已经成为提高聚合物相容的一个重要手段。甲基丙烯酸缩水甘油配(GMA)、马来酸酐(MAH)和丙烯酸(AA)作为主要的接枝单体己得到广泛应用。本文从GMA、MAH和AA官能化聚合物的作用机理，以及他们作为反应型相容剂，通过“原位”反应增容聚合物共混体系，提高聚合物合金的相容性两个方面，介绍了国内外在反应型增容这一领域内所取得的进展。     

RPS／CPE的反应性共混及其对PS／PE的增容作用

用ＦＴＩＲ、ＤＳＣ等方法研究了含恶唑啉官能力的聚苯乙烯（ＲＰＳ）与氯化聚乙烯（ＣＰＥ）之间的反应。ＲＰＳ、ＣＰＥ、ＰＳ、ＰＥ在不同温度下用反应式挤出要熔融共辊，结果表明，ＲＰＳ／ＣＰＥ对ＰＳ／ＰＥ共混物具有增容作用，提高了共混物的力学性能。此反应性共混适宜在较低温度下进行，对ＲＰＳＣＰＥ共混物还进行了动态力学表征，并与ＲＰＳ进行比较以进一步了解共混物的特征。     

Compatibilizing effect of functionalized polystyrene blends: a study of morphology,thermal, and mechanical properties

Polystyrene (PS), being an amorphous polymer is immiscible with other polymers. To engender miscible blends, PS has been functionalized with an active amino‐functional group on the molecular chains of PS to yield amino‐substituted polystyrene (APS), which serves as a reactive compatibilizer. The compatibilization effect of amino functionalized polystyrene on the rubber toughening was explored and results were compared in terms of morphology, thermal, and mechanical properties of PS/SEBS‐g‐MA versus APS/SEBS‐g‐MA blends. In addition, the effect of rubber content on the blend morphology and mechanical properties were investigated. An appreciable change in the thermal stability of APS blends in comparison with PS blend has been probed. A marked correlation has been observed between phase morphology and thermal stability. Use of APS produced the compatibilized blends which render improved blend morphology, enhanced thermal and mechanical properties. Optimal thermal, morphological and mechanical profiles were depicted by 20‐wt% APS blend. Copyright © 2008 John Wiley & Sons, Ltd.     

Improvement in toughness of poly(l-lactide) (PLLA) through reactive blending with acrylonitrile-butadiene-styrene copolymer (ABS): Morphology and properties

Poly(l-lactide) (PLLA) was melt-blended with acrylonitrile-butadiene-styrene copolymer (ABS) with the aim of enhancing impact strength and elongation at break of PLLA, but not sacrificing its modulus and stiffness significantly. However, PLLA and ABS were found to be thermodynamically immiscible by simply melt blending and the formed blends show deteriorated mechanical properties. The reactive styrene/acrylonitrile/glycidyl methacrylate copolymer (SAN-GMA) by incorporating with ethyltriphenyl phosphonium bromide (ETPB) as the catalyst was used as the in situ compatibilizer for PLLA/ABS blends to improve the compatibility between PLLA and ABS. The reactive process during melt blending was investigated by Fourier transformed infra-red (FTIR). It showed that the epoxide group of SAN-GMA reacted with PLLA end groups under the mixing conditions and that the addition of ETPB accelerated the reaction. Phase structure and physical properties of the compatibilized blends were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic mechanical analysis (DMA), tensile tests and impact property measurements. It was found that the size of ABS domains in PLLA matrix is significantly decreased by addition of the reactive compatibilizer. The dynamic mechanical analysis revealed markedly shifted glass transition temperatures for both PLLA and ABS, indicating the improved compatibility between PLLA and ABS. The mechanical tests showed the compatibilized PLLA/ABS blends had a very nice stiffness-toughness balance, i.e., the improved impact strength and the elongation at break with a slightly loss in the modulus.     

Synthesis and characterization of polyethylene‐g‐polystyrene as the compatibilizer for polypropylene/ Polystyrene blends

Polyethylene‐g‐polystyrene (PE‐g‐PS) was synthesized as a compatibilizer for polypropylene/polystyrene­(PP/PS) blends by the living radical polymerization of styrene with polyethylene‐co‐glycidylmethacrylate (PE‐co‐GMA). The compatibilizer effect of PE‐g‐PS on the morphology and thermal properties of PP/PS blends was investigated. The crystalline temperature of PP in PP/PS blends decreased with increasing PE‐g‐PS contents. Morphologies of PP/PE‐g‐PS/PS blends showed much better dispersion of each domain for higher PE‐g‐PS contents. The molecular weight of PS segment in PP/PE‐g‐PS/PS blend was increased by addition of styrene monomer during the post melt blending process where post living radical polymerization reaction proceeded. Copyright © 2003 John Wiley & Sons, Ltd.     

EFFECTS OF STYRENE-ETHYLENE/PROPYLENE DIBLOCK COPOLYMER (SEP) ON THE COMPATIBILIZATION OF PP/PS BLENDS

The effects of styrene-ethylene/propylene (SEP) diblock copolymer on the morphology and mechanical propertiesof polypropylene/polystyrene (PP/PS) blends were investigated. The results showed that SEP diblock copolymer, acting as acompatibilizer in PP/PS immiscible blends, can diminish the coalescence of the dispersed particles, reduce their averageparticle size, change their phase morphologies significantly, and increase the mechanical properties. It was found that SEP has better compatibilization effects on the PP/PS (20/80) blends.     

Barrier,Mechanical, Morphological and Thermal Properties of Compatibilized High Density Polyethylene and Polyamide 6 Blends

Effectiveness of the content of maleic anhydride (MAH) and polyamide 6 (PA6) on mechanical, thermal, barrier (moisture and oxygen) properties of HDPE/PA6 blends was investigated. Blends of HDPE with PA6 were prepared by in situ method. Molau test and FTIR spectroscopy results confirmed the reactive compatibilization through grafting of MAH on HDPE and PA6 chains in PA6/HDPE blends. Low concentration of benzoyl peroxide (BPO) and MAH reduced the particle size, improved phase morphology and mechanical properties of PA6/HDPE blends. Decrease in mechanical properties of PA6/HDPE blends was observed at high concentration of BPO and MAH.     

Structure,properties and interfacial interactions in poly(lactic acid)/polyurethane blends prepared by reactive processing

Polyurethane elastomers are promising candidates for the impact modification of PLA producing blends for example for biomedicine. Poly(lactic acid) (PLA)/polyurethane elastomer (PU) blends were prepared by reactive processing and physical blending as comparison. The blends were characterized by a number of techniques including microscopy (scanning electron microscopy, SEM, and atomic force microscopy, AFM), rotational viscometry, thermal (dynamic mechanical analysis, DMA), and mechanical (tensile) measurements. The analysis and comparison of the structure and properties of physical and reactor blends proved the successful coupling of the phases. Coupling resulted in more advantageous structure and superior mechanical properties compared to those of physical blends as confirmed by morphology, macroscopic properties and the quantitative estimation of interfacial interactions. Structural studies and the composition dependence of properties indicated the formation of a submicron, phase-in-phase structure which positively influenced properties at large PU contents. The results strongly support that reactive processing is a convenient, cost-effective and environmentally friendly technique to obtain blends with superior properties.     

Miscibility and compatibilization of poly(trimethylene terephthalate)/acrylonitrile-butadiene-styrene blends

Poly(trimethylene terephthalate)/acrylonitrile-butadiene-styrene (PTT/ABS) blends were prepared by melt processing with and without epoxy or styrene-butadiene-maleic anhydride copolymer (SBM) as a reactive compatibilizer. The miscibility and compatibilization of the PTT/ABS blends were investigated by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), capillary rheometer and scanning electron microscopy (SEM). The existence of two separate composition-dependent glass transition temperatures (T_gs) indicates that PTT is partially miscible with ABS over the entire composition range. In the presence of the compatibilizer, both the cold crystallization and glass transition temperatures of the PTT phase shifted to higher temperatures, indicating their compatibilization effects on the blends.The PTT/ABS blends exhibited typical pseudoplastic flow behavior. The rheological behavior of the epoxy compatibilized PTT/ABS blends showed an epoxy content-dependence. In contrast, when the SBM content was increased from 1 wt% to 5 wt%, the shear viscosities of the PTT/ABS blends increased and exhibited much clearer shear thinning behavior at higher shear rates. The SEM micrographs of the epoxy or SBM compatibilized PTT/ABS blends showed a finer morphology and better adhesion between the phases.     

Facile fabrication of thermoplastic ternary copolymerized polyamide and maleated polyethylene shape memory blends

Novel thermoplastic shape memory blends of ternary copolymerized polyamide (PAM) and maleated polyethylene (PE-g-MAH) were prepared by a simple melt-blending method, which might provide a new way for the industrial production of thermoplastic shape memory materials. The new chemical bonds were generated between PAM and PE-g-MAH, which was essential for enhancement of properties. The mechanical, thermal and shape memory properties of the blends were investigated in detail. It was found that the microstructure and proportion of different constituents was vital for the shape memory properties of the blends. In PAM/PE-g-MAH blends, a crystalline region of PAM acted as a fixed domain, and the crystalline region in PE-g-MAH acted as a reversible domain. The synergistic effect of the fixed and reversible domains determined the shape memory behavior of the blends. When the blend ratio of PAM/PE-g-MAH was 30/70, the composites exhibited the best shape memory properties, with a shape fixity ratio of 95.5% and a shape recovery ratio of 79.8%.     

Preparation and characterization of PE and PE-g-MAH/montmorillonite nanocomposites

Polyethylene (PE) was chemically modified with grafting maleic anhydride (MAH) monomer on its backbone at first. Then the melt-direct intercalation method was employed to prepare two kinds of nanocomposites, polyethylene (PE)/organic montmorillonite (Org-MMT) and maleic anhydride grafted polyethylene (PE-g-MAH)/Org-MMT nanocomposites. X-ray diffractometery (XRD) was used to investigate the intercalation effect and transmission electron microscopy (TEM) to observe the dispersion of Org-MMT interlayers in matrixes. The results show that an intercalated structure would be acquired on mixing the PE and Org-MMT; and an almost exfoliated system would be obtained by mixing the PE-g-MAH and Org-MMT. Moreover, further measurements via thermogravimetric (TGA) and differential scanning calorimetry (DSC) showed that both of the nanocomposites had a higher thermal decomposition temperature and a higher crystallization temperature when compared to the original matrix. At the same time, the thermal and crystal properties for the PE-g-MAH prepared in this experiment are also discussed.