Preparation of fully cross-linked CNBR/PP-g-GMA and CNBR/PP/PP-g-GMA thermoplastic elastomers and their morphology, structure and properties

Binary CNBR/PP-g-GMA and ternary CNBR/PP/PP-g-GMA thermoplastic elastomers were prepared by reactive blending carboxy nitrile rubber (CNBR) powder with nanometer dimension and polypropylene functionalized with glycidyl methacrylate (PP-g-GMA). Morphology observation by using an atomic force microscope (AFM) and TEM revealed that the size of CNBR dispersed phase in CNBR/PP-g-GMA binary blends was much smaller than that of the corresponding CNBR/PP binary blends. Thermal behavior of CNBR/PP-g-GMA and CNBR/PP blends was studied by DSC. Comparing with the plain PP-g-GMA, T, of PP-g-GMA in CNBR/PP-g-GMA blends increased about 10degreesC. Both thermodynamic and kinetic effects would influence the crystallization behavior of PP-g-GMA in CNBR/PP-g-GMA blends. At a fixed content of CNBR, the apparent viscosity of the blending system increased with increasing the content of PP-g-GMA. FTIR spectrum verified that the improvement of miscibility of CNBR and PP-g-GMA was originated from the reaction between carboxy end groups of CNBR and epoxy groups of GMA grafted onto PP molecular chains. Comparing with CNBR/PP blends, the tensile strength, stress at 100% strain, and elongation at break of CNBR/PP-g-GMA blends were greatly improved.

Morphology and thermal and mechanical properties of PBT/HIPS and PBT/HIPS-g-GMA blends

The modification of high-impact polystyrene (HIPS) was accomplished by melt-grafting glycidyl methacrylate (GMA) on its molecular chains. Fourier transform infrared spectroscopy and electron spectroscopy for chemical analysis were used to characterize the formation of HIPS-g-GMA copolymers. The content of GMA in HIPS-g-GMA copolymer was determined by using the titration method. The effect of the concentrations of GMA and dicumyl peroxide on the degree of grafting was studied. A total of 1.9% of GMA can be grafted on HIPS. HIPS-g-GNU was used to prepare binary blends with poly(buthylene terephthalate) (PBT), and the evidence of reactions between the grafting copolymer and PBT in the blends was confirmed by scanning electron microscopy (SEM), dynamic mechanical analysis, and its mechanical properties. The SEM result showed that the domain size in PBT/HIPS-g-GMA blends was reduced significantly compared with that in PBT/HIPS blends; moreover, the improved strength was measured in PBT/HIPS-g-GMA blends and results from good interfacial adhesion. The reaction between ester groups of PBT and epoxy groups of HIPS-g-GMA can depress crystallinity and the crystal perfection of PBT.

The compatibility and morphology of HIPS/PC and HIPS-g-GMA/PC blends

The compatibility and morphology of HIPS/PC and HIPS-g-GMA/PC blends were studied. The compatibility and morphology of HIPS/PC blends were characterized by DSC and SEM, respectively. The result of DSC shows that T-g of PS doesn't change with the blend composition, and T-g of PC decreases with the increase in weight fraction of HIPS, which indicates that the PC/HIPS blend is a partially miscible system. Results of SEM indicate that the decrease in T-g of PC results from PS interpenetrating into the phase of PC, and no change in T-g of PS results from PC not interpenetrating into the phase of PS. The copolymer of HIPS-g-GMA was prepared by reactive grafting method. The IR spectrum shows that GMA is grafted on the chain of HIPS. The compatibility and morphology of HIPS-gGMA (35)/PC (65) were studied by DSC and SEM. PC (65)/HEPS-g-GMA (35) blend exhibits reduced size of disperse phase, enhanced interface adhesion and lower T-g of PC phase as compared with the PC(65)/HIPS(35) blend. It implies that HIPS-g-GMA is an effective compatibilizer of the HIPS/PC blend.

反应挤出条件对PP-g-GMA接枝率、接枝效率和熔体流动速率的影响

用反应挤出法在聚丙烯 (PP)分子链上接枝甲基丙烯酸环氧丙酯 (GMA) ,制备功能化聚丙烯 .重点讨论了单体浓度、引发剂浓度、反应温度及物料在螺杆中的停留时间等对接枝产物 PP-g-GMA的接枝率、接枝效率和熔体流动速率的影响 .结果表明 ,PP-g-GMA接枝率与加入的单体浓度成正比 ,与引发剂浓度无关 ,反应挤出的适宜温度窗口在 1 95～ 2 3 0℃之间 ,停留时间超过 1 min后接枝率与停留时间无关 ;PP-g-GMA的熔体流动速率与单体浓度成反比 ,与引发剂的用量成正比 ,在反应温度窗口内与反应挤出温度和物料停留时间关系不大 ;单体和引发剂的浓度、反应挤出温度及物料停留时间对 PP-g-GMA的接枝效率无显著影响 .

PA46/PP-g-GMA合金的研制和表征

用反应挤出方法制备了PA46/PP-g-GMA合金。研究了合金的力学性能,吸水性与形态结构的关系。与PA46/PP相比,PA46/PP-g- GMA的力学性能如拉伸强度,杨氏模量,弯曲强度,弯曲模量以及冲击强度都有不同程度的提高。PA46/PP-g-GMA的吸水率比PS46/PP大幅度降低。用扫描电镜(SEM)研究了PA46/PP-g-GMA和PA46/PP样品的冲击断面。PA46/PP-g-GMA中的PP-g-GMA分散相粒子半径远比PA46/PP中的PP相粒子半径小和均匀。这表明改性后的PP-g-GMA与PA46的相容性有很大的改观。DMA研究结果表明,PA46 /PP-g-GMA样品的储能模量比相同组分的PP/PA46高。在组成为50/50时PA46/PP-g-GMA的软化点温度比PA46/PP高 120℃。

Effects of the compatibilizer PP-g-GMA on morphology and mechanical properties of PP/PC blends

Effects of the compatibilizer polypropylene grafted with glycidyl methacrylate(PP-g-GMA) on the morphology, thermal, rheological and mechanical properties of polypropylene and polycarbonate blends (PP/PC) were studied. It was found that the addition of PP-g-GMA significantly changed their morphology. The mean size of domains reduced from 20 mu m to less than 5 mu m. The dispersed domain size is also strongly dependent upon the content of PP-g-GMA. The interfacial tension of PP/PC/PP-g-GMA (50/30/20) is only about one-tenth of PP/PC (70/30). The crystallization temperature of PP in PP/PC/PP-g-GMA is 5-8 degrees C higher than that of PP in PP/PC blends. Characterization studies based on mechanical properties, differential scanning calorimetry, rheology and morphological evidence obtained by using scanning electron microscopy support the hypothesis that an in-situ copolymer PP-g-PC was formed during the blending process. (C) 1997 Elsevier Science Ltd.

Morphology, mechanical properties and interfacial behaviour of PA1010/PP/PP-g-GMA ternary blends

Morphology, mechanical properties, and interfacial interaction of polyamide 1010/polypropylene (PA1010/ PP) blends compatibilized with polypropylene grafted with glycidyl methacrylate (PP-g-GMA) were studied. It was found that the size of the PP domains, tensile and impact strength of ternary blends, and adhesion fracture energy between two layers of PA1010 and PP were all significantly dependent on the PP-g-GMA contents in the PP layer. Correlations between morphology and related properties were sought. The improvements in properties have been attributed to chemical and physical interaction occurring between PA1010 and PP-g-GMA. (C) 1997 Elsevier Science Ltd.

Morphology, thermal behavior, and mechanical properties of PA1010/PP and PA1010/PP-g-GMA blends

The modification of polypropylene (PP) was accomplished by melt grafting glycidyl methacrylate (GMA) on its molecular chains. The resulting PP-g-GMA was used to prepare binary blends of polyamide 1010 (PA1010) and PP-g-GMA. Different blend morphologies were observed by scanning electron microscopy (SEM) according to the nature and content of PA1010 used. Comparing the PA1010/PP-g-GMA and PA1010/PP binary blends, the size of the domains of PP-g-GMA were much smaller than that of PP at the same compositions. It was found that mechanical properties of PA1010/PP-g-GMA blends were obviously better than that of PA1010/PP blends, and the mechanical properties were significantly influenced by wetting conditions for uncompatibilized and compatibilized blends. A different dependence of the flexural modulus on water was found for PA1010/PP and PA1010/PP-g-GMA. These behaviors could be attributed to the chemical interactions between the two components and good dispersion in PA1010/PP-g-GMA blends. Thermal and rheological analyses were performed to confirm the possible chemical reactions taking place during the blending process. (C) 1997 John Wiley & Sons, Inc.

Isothermal crystallization of PP-g-GMA copolymer

The overall isothermal crystallization kinetics for neat polypropylene and grafted polypropylene systems were investigated. The rate constants were corrected assuming the heterogeneous nucleation and three dimensional growth of polypropylene spherulites. A semiempirical equation for the radial growth rate of polypropylene spherulites was developed as a function of temperature, and was used to determine the number of effective nuclei of different temperatures. The number of nuclei in grafted samples was estimated to be 10(2)-10(3) times larger than that of neat polypropylene. (C) 1997 John Wiley & Sons, Inc.

EP－g－GMA热学行为表征

本文用ＤＳＣ研究了乙丙共聚物接枝甲基丙烯酸环氧丙酯（ＥＰ－ｇ－ＧＭＡ）的热学性质。与空白乙丙共聚物相比，接枝共聚物中丙烯序列的结晶温度升高了８～１２℃，熔融热焓增加了４～６Ｊ／ｇ。乙烯序列的结晶温度却稍有下降，其相应熔点及熔融热熔都有相应下降。等温与非等温结晶动力学表明接枝样品中丙烯序列的结晶速率高于相应的未接枝样品，ＥＰ－ｇ－ＧＭＡ的Ａｖｒａｍｉ指数及Ｚｉａｂｉｃｋｉ指数均高于空白ＥＰ，接枝到乙丙共聚物乙烯序列上的甲基丙烯酸环氧雨酯（ＧＭＡ）可能成为丙烯序列结晶的成核剂，加速了丙烯的成核速度和晶体增长速度。

The determination of ethylene-propylene copolymer-grafted-glycidyl methacrylate by the contact angle method

The contact angles theta of some liquids on ethylene-propylene copolymer-grafted-glycidyl methacrylate (EPM-g-GMA) were measured. The critical surface tensions r(c) of EPM-g-GMA were evaluated by the Zisman Plot (cos theta versus r(L)), Young-Dupre-Good-Girifalco plot (1 + cos theta versus 1/r(L)(0.5)) and log (1 + cos theta) versus log(r(L)) plot. The following results were obtained: the r(c) values varied significantly with the estimation methods. The critical surface tension r(c) decreased with the increase of the degree of grafting of EPM-g-GMA.

尼龙1010/乙丙共聚物共混体系形态与性能研究

在过氧化二异丙苯(DCP)的引发下,用反应挤出的方法制备了乙丙共聚物接枝甲基丙烯酸环氧丙酯(EPM-g-GMA).用Brabender单螺杆挤出机制备了不同组成的EPM/尼龙1010及EPM-g-GMA/尼龙-1010的共混物.用电子显微镜观察了不同共混组成的形态.与EPM/尼龙1010共混体系相比,EPM-g-GMA/尼龙1010体系中EPM在尼龙1010中分散相尺寸明显降低,EPM-g-GMA的加入对该共混体系的物理机械性能有明显改善.

PBT和PBS及其共混物结晶行为和力学性能的研究

聚对苯二甲酸丁二醇酯(PBT)是一种多用途的工程塑料。本文中，主要研究了PBT/Epoxy(E)合金及PBT/ABS-g-GMA/E合金的结晶行为和力学性能。 使用示差扫描量热法对PBT/Epoxy合金的等温结晶过程进行了研究。发现PBT和E03 609环氧树脂在所研究的组成范围内完全相容。环氧树脂起到异相成核剂的作用，使PBT产生更强的瞬间结晶三维生长趋势。PBT和环氧树脂的Flory相互作用参数为负值，说明PBT和环氧树脂形成了热力学上的稳定混合物。 使用几种方法对PBT/Epoxy合金的非等温结晶过程进行了研究，Ozawa方程不能充分描述PBT/Epoxy合金的非等温结晶过程；使用莫志深等人提出的方法，成功地描述了该过程。实验结果显示1％环氧树脂可使PBT/Epoxy合金结晶速率明显增加。 对PBT/Epoxy合金的热和力学性能进行了研究。1％环氧树脂的加入提高PBT/Epoxy合金的缺口冲击强度20%；从红外光谱分析，环氧树脂与PBT发生了相互作用；环氧树脂影响了PBT/Epoxy合金的力学性质和结晶行为。 采用乳液聚合技术将甲基丙烯酸环氧丙酯(GMA)引入到ABS的壳层，合成了环氧官能化的ABS共聚物(ABS-g-GMA)，将环氧树脂加入到PBT/ABS-g-GMA合金中，利用环氧官能团与PBT端羧基/羟基的反应达到增容PBT/ABS合金的目的。当环氧树脂的含量为5％时，PBT/ABS-g-GMA/E共混物比PBT/ABS-g-GMA共混物有更优异的力学性质。 研究了聚亚丙基碳酸酯(PPC)和聚丁二酸二甲酯(PBS)共混物的相容性、结晶和力学性能。结果显示组份PPC/PBS（90/10）可能产生部分相容。采用偏光显微镜观察了PPC/PBS共混物的形态，对于90/10 PPC/PBS共混物，发现很大数量的PBS小球晶分散在PPC基质中。力学结果显示90/10 PPC/PBS共混物拉伸强度比纯PPC提高了30％，冲击强度提高了11％。

功能化聚丙烯及其与聚对苯二甲酸丁二醇酯共混物的制备及结构性能研究

本工作通过电子束预辐照处理和反应挤出方法，制备了丙烯酸功能化预辐照聚丙烯rPP-g-AA，采用化学滴定和红外光谱方法均证明接枝共聚物的存在，同时确定了预辐照剂量和单体浓度对接枝率的影响：（1）当单体浓度一定时，接枝率随预辐照剂量的增加而增加并逐渐达到平台值；（2）当预辐照剂量固定时，单体浓度在0～4.0wt%范围内，接枝率几乎呈线性增加。研究发现，丙烯酸(AA)接枝链能起到异相成核作用而促进预辐照聚丙烯(rPP)的结晶过程，但却不改变结晶晶型；虽然接枝反应可以部分抑制降解反应，但相对于原料聚丙烯(PP)，接枝产物的力学性能仍大大下降；因此提出的反应机理认为接枝反应主要是通过链断裂降解反应形成的端自由基引发的，从而形成了以端基接枝为主的产物。 为了控制PP接枝过程中的严重降解，本工作首次提出了均相和异相引发接枝反应的原理，即采用部分rPP和预辐照聚乙烯(rPE)分别作为PP接枝反应的均相和异相“引发剂”，经反应挤出制备丙烯酸功能化聚丙烯PP-g-AA。对于均相引发体系：（1）当rPP用量为20phr时，PP-g-AA的接枝率已经达到rPP-g-AA的水平，而且降解反应得到有效控制；（2）和PP/rPP-g-AA共混物的对比研究证明，均相引发接枝产物不但接枝率明显提高，而且接枝分布非常均匀；（3）由此提出均相引发主要是发生rPP和PP分子间夺氢反应并形成以基体PP接枝为主的产物，而rPP分子内夺氢反应形成的接枝产物rPP-g-AA只占较少比例。对于异相引发体系： （1）通过红外光谱表征及接枝率计算得出异相引发接枝产物的接枝率比相应的PP/ rPE-g-AA共混物略高；（2）由于rPE及rPE-g-AA对基体PP的结晶没有影响，通过异相引发接枝产物中PP的结晶温度升高直接验证了异相引发接枝反应的实现；（3）提出的机理认为异相引发主要发生在rPE的分子内夺氢并形成rPE-g-AA，造成rPE引发的PP分子间夺氢反应形成PP-g-AA产物的比例下降。 本工作还详细研究了rPP预辐照剂量、rPP用量和单体浓度对均相引发反应的影响。得到的结果如下：（1）高预辐照剂量导致了接枝率下降的“假相”是由于形成的微凝胶造成的；（2）rPP用量的增大在提高接枝率的同时也导致降解反应的逐渐增强；（3）单体浓度的增加导致接枝率的逐步提高并最终达到最大值，而且可能导致部分微凝胶的产生；（4）接枝没有破坏PP-g-AA结晶的完善性和晶型，却能促进了晶体在（040）晶面的生长并可能产生部分横晶形态；（5）PP-g-AA和金属能形成良好的粘接作用。 以上述制备的rPP-g-AA和PP-g-AA增容PP/聚对苯二甲酸丁二醇酯(PBT)共混体系，发现高分子量的PP-g-AA比低分子量的rPP-g-AA的增容效果要好，因此认为PP-g-AA和PBT通过酯化反应形成的长链接枝共聚物PP-g-PBT对PBT相的分散和界面作用增强更加有效。而随着增容剂PP-g-AA比例的增加，原位反应生成的PP-g-PBT逐渐增加，使得PBT相分散和界面增强效果更加显著，因此共混物的力学性能也更佳；DSC研究发现，随着PBT相尺寸减小到1μm以下，PBT出现了结晶受限行为。 将引发剂rPP和单体AA加入到PP/PBT共混体系中实现了一步法反应增容，得到共混物的扭矩、相形态、力学性能都和分步法增容共混物的结果几乎相同，这说明一步法共混能使PBT产生良好分散并得到性能较佳的产物，从而为高分子合金材料制备提供了一种简单有效的方法。 采用该方法对AA、马来酸酐(MAH)和甲基丙烯酸甘油酯(GMA)三种单体的接枝和增容反应对比研究证明，AA的效果最好，MAH次之，而GMA的效果最差，分析认为，AA和MAH通过接枝反应形成PP-g-AA和PP-g-MAH，随后再和PBT发生酯化增容反应形成PP-g-MAH-PBT共聚产物，而GMA首先和PBT反应形成PBT-GMA，而后由长链PBT-GMA发生接枝反应生成PP-g-GMA-g-PBT，但是这种接枝反应的效率很低，由此造成增容效果较差。