PVC／LLDPE共混物研究

本文探讨了改进聚乙烯/线形低密度聚乙烯机械性能的方法,以作为再加工聚合物废料包括混合物的方法,发现氯化聚乙烯是提高此类共混物拉伸强度和加工性能的有效添加剂,亦发现化学法或辐射法共交联能提高强度和刚性.     

胶粉/PVC共混材料的研究

研究了胶粉／ＰＶＣ二元体系、胶粉／ＰＶＣ／ＣＰＥ三元体系共混材料的力学性能。实验结果表明：三元体系的综合性能优于二元体系;胶粉粒径和胶粉含量对共混材料的力学性能有较大的影响,胶粉粒径在８０～１００目为好,胶粉含量在５～１０份为佳;胶粉与ＣＰＥ同时添加到ＰＶＣ基体时,能明显改善共混材料的冲击性能,而且两者起着协同效应。     

改性石油树脂的合成及其增容PVC/PE共混物的研究

通过对石油树脂与顺丁烯二酸酐反应条件的考察，确定了其最佳反应条件。运用顺酐化石油树脂与异辛醇酯化反应制备了改性石油树脂(MPR)，并将其作为聚氯乙烯／聚乙烯(PVC／PE)的增容剂，研究了PVC／MPR／PE共混体系的相容性、加工性及其材料的力学性能。结果表明，MPR是PVC／PE共混物的一种良好增容剂，PVC／MPR／PE质量比为100／8／6时，共混物具有良好的塑化效果和流动性能，优良的综合性能。     

PVC／PE共混体系的研究—ELVALOY741,EVA对PVC／LLDPE共混物的增容作用

本文采用 ELvaloy741、EVA 作为 PVC/LLDPE 共混物的增容剂,用机械共混法制样,研究了增容剂含量对共混物的力学性能、熔体流动性能及相态结构的影响。实验结果表明,增容剂含量对共混物的上述三种性能影响呈现一定的规律性,增容剂含量适当,能不同程度地改善共混体系的力学和加工性能。     

PVC／PE共混体系相态形貌分析新方法

本文建立了一种研究聚合物共混物相态结构形貌的新方法——近θ溶剂显示法。用 PVC 的近θ溶剂处理 PVC、LDPE 共混薄膜,使 PVC 相由透明转变成不透明,LDPE 相仍保持透明,明显地提高了两相的反差。此时可以用光学显微镜观察到非常清晰的相态结构。此外,本文还探讨了不同 PVC/LDPE 配比时的共混物相态形OQL 的变化及其对共混材料力学性能的影响。     

PVC／HRA共混物耐热与力学性能研究

以ＰＭＩ－Ｓｔ－ＡＮ三元共聚物为热改性剂,以ＡＣＲ为抗冲改性剂,对ＰＶＣ进行耐热和抗冲改性研究,探讨了共混温度及两种改性剂用量等对共混物物理。力学性能和耐热性能的影响,通过优化制备了耐热,抗冲性能兼备的ＰＶＣ共混改性新材料。     

PVC/PE基木塑复合材料性能研究

以氯化聚乙烯(CPE)、马来酸酐接枝聚乙烯(MAPE)、聚丙烯酸酯(ACR)为改性剂,采用二辊开炼机制备PVC/PE共混体系及其木塑复合材料(WPC),并采用热压成型的方法制备材料试样.考察了改性剂和木粉对PVC/PE及其WPC力学性能、加工性能及动态热机械性能的影响.结果显示:CPE能够显著提高PVC/PE共混体系的机械性能,使材料加工性能下降,储能模量降低;MAPE则能使PVC木塑复合材料力学性能大幅提高;ACR则能够提高材料的加工性能,使材料储能模量增大;木粉的加入使复合材料加工性能大幅下降,材料储能模量提高,损耗因子下降.     

MBS/CaCO3协同增韧PVC的性能研究

分别研究了1 250目、2 500目CaCO3以及甲基丙烯酸-丁二烯-苯乙烯共聚物(MBS)对聚氯乙烯(PVC)力学性能的影响;并且选用15%MBS与1 250目CaCO3复配制备出了高韧性的PVC材料。结果表明:MBS能有效提高PVC的冲击强度;1 250目CaCO3与2 500目CaCO3相比,更易于分散,增韧的效果更好;MBS与1 250目CaCO3协同增韧,使PVC冲击强度达120 kJ/m2,拉伸强度约为37 MPa,断裂伸长率在40%左右。     

Comparative Studies of Mechanical and Interfacial Properties Between Jute Fiber/PVC and E-Glass Fiber/PVC Composites

Composites (50 wt% fiber) of jute fiber reinforced polyvinyl chloride (PVC) matrix and E-glass fiber reinforced PVC matrix were prepared by compression molding. Mechanical properties such as tensile strength (TS), tensile modulus (TM), bending strength (BS), bending modulus (BM) and impact strength (IS) of both types of composites was evaluated and compared. Values of TS, TM, BS, BM and IS of jute fiber/PVC composites were found to be 45 MPa, 802 MPa, 46 MPa, 850 MPa and 24 kJ/m², respectively. It was observed that TS, TM, BS, BM and IS of E-glass fiber/PVC composites were found to increase by 44, 80, 47, 92 and 37.5%, respectively. Thermal properties of the composites were also carried out, which revealed that thermal stability of E-glass fiber/PVC system was higher. The interfacial adhesion between the fibers (jute and E-glass) and matrix was studied by means of critical fiber length and interfacial shear strength that were measured by single fiber fragmentation test. Fracture sides after flexural testing of both types of the composites were investigated by Scanning Electron Microscopy.     

PVC/稻壳复合材料塑化性能与动态黏弹特性研究

通过MMA在微波作用下改性稻壳粉研究了PVC/稻壳粉复合材料的塑化性能与动态黏弹特性。结果表明,加工温度为140℃时,凝胶化程度为零,物料塑化很差;85℃时,熔体凝胶化程度达85%。稻壳粉的加入大大提高了复合材料的刚性,40份稻壳粉的复合材料在60℃的储能模量仍与纯PVC常温时的模量相当;与纯PVC相比,MMA处理PVC/稻壳粉的复合材料损耗因子峰值明显减小。MMA改性稻壳粉的复合材料的α值比未改性的大,表明改性后复合材料相容性好。     

纳米SiO2改性EP对基体力学性能和芳纶纤维/EP复合材料界面性能的影响

研究了纳米SiO2对环氧树脂(EP)基体力学性能的影响,并进一步采用对位芳纶纤维(F-12)增强环氧树脂,制备了NOL环复合材料,通过复合材料层间剪切性能测试考核了F-12与环氧树脂之间的界面粘接性能.结果表明:环氧树脂中添加适量的纳米SiO2能够有效提高环氧树脂浇注体的拉伸强度、拉伸弹性模量、冲击强度.纳米SiO2的加入,可以有效改善F-12与环氧树脂基体之间的界面粘接性能,降低复合材料的空隙率,F-12/纳米SiO2(6%)-EP复合材料的层间剪切强度(ILSS)提高约60.3%.     

聚氯乙烯/蒙脱土纳米复合材料的研究

采用熔融插层法制备了聚氯乙烯(PVC) /蒙脱土(MMT)纳米复合材料并进行了表征,研究了PVC/MMT纳米复合材料的力学性能。结果表明:PVC进入到有机MMT的片层间形成了纳米复合材料,但PVC不能进入钠基MMT的片层间,形成纳米复合材料;蒙脱土的加入提高了PVC的力学性能,而且PVC/有机MMT纳米复合材料的拉伸和冲击强度总是优于PVC/钠基MMT复合材料;对PVC/有机MMT纳米复合材料而言,复合材料的V型缺口冲击比U型缺口冲击敏感,其力学性能随热处理时间延长而降低,但PVC/有机MMT复合材料比PVC/钠基MMT的抗热性好。     

Adhesion of polyethylene blends to polypropylene

The effect of chain microstructure on adhesion of ethylene copolymers to polypropylene (PP) was studied using coextruded microlayers. Adhesion was measured by delamination toughness G using the T-peel test, and interfacial morphology was examined by atomic force microscopy. Good adhesion to PP was achieved with homogeneous metallocene catalyzed copolymers (mPE) with density 0.90 g cm⁻³ or less. Good adhesion was attributed to entanglement bridges. In contrast, a heterogeneous Ziegler-Natta catalyzed copolymer (ZNPE) of density 0.925 g cm⁻³ exhibited poor adhesion to PP due to an amorphous interfacial layer of low molecular weight, highly branched fractions that prevented effective interaction of ZNPE bulk chains with PP. Blending mPE with ZNPE eliminated the amorphous interfacial layer and resulted in epitaxial crystallization of ZNPE bulk chains with some increase in G. Increasing the mPE content of the blend past the amount required to completely resolve the amorphous interfacial layer of ZNPE resulted in a steady, almost linear, increase in G. Phase separation of mPE and ZNPE during crystallization produced an interface with regions of epitaxially crystallized ZNPE bulk chains and other regions of entangled mPE chains. Entanglement bridges imparted much better adhesion than did epitaxially crystallized lamellae.     

废弃PVC电缆料的回收利用及性能研究

将聚氯乙烯(PVC)电缆料废弃物(wPVC)通过双螺杆挤出机,把不同份数的wPVC加入到未使用过的J-70型PVC电缆料(J-70PVC)中混合制备wPVC/J-70PVC,再用注射机注塑成型的方法来制得标准样条.研究不同配比wPVC/J-70PVC的拉伸、热老化、体积电阻率等性能,并对其拉伸断面形貌的微观性能进行测试...     

新型超支化聚酯对透明PVC热稳定性及力学性能的影响研究

超支化聚(胺-酯)是一种具有高度支化结构的新型超支化聚酯。将超支化聚(胺-酯)作为为改性剂添加到透明聚氯乙烯(PVC)树脂中,研究了其对透明PVC树脂热稳定性和力学性能的影响。结果表明,新型超支化聚(胺-酯)的添加可改善透明聚氯乙烯树脂的热稳定性,使5%失重温度提高3~6℃;同时,不同代数超支化聚(胺-酯)的添加均会对透明聚氯乙烯树脂的力学性能有显著影响,其中,第3代超支化聚(胺-酯)的含量为3%时,透明聚氯乙烯树脂具有最佳的拉伸强度、断裂伸长率,而当超支化聚(胺-酯)的含量为5%时,透明聚氯乙烯树脂冲击韧性达到最佳。     

Interfacial compatibilization for PSF/TLCP blends by a modified polysulfone

Maleic anhydride-grafted polysulfone (PSF-g-MAH) was prepared by copolymerization in a solution. Compared to polysulfone, the surface tension and its polar fraction of PSF-g-MAH were increased by modification. The PSF-g-MAH was used to compatibilize polysulfone (PSF)/thermotropic liquid crystalline polymer (TLCP) (Vectra B950) blends. DRS-FTIR investigations showed that the special interaction between PSF and TLCP phases was enhanced due to the incorporation of PSF-g-MAH. The X-ray photoelectron spectroscopy (XPS) and PLM studies revealed that some chemical reactions had occurred between PSF-g-MAH and TLCP components, which produced PSF-VB copolymers. It is suggested that the improvement of compatibility should be attributed to some interactions including both chemical and physical ones. The improvement of compatibility was also confirmed by DMA and TGA analysis. Morphological observation showed that the addition of compatibilizer significantly reduced the size of the dispersed TLCP phase, and in case of injection molding, PSF-g-MAH promoted the TLCP fibrillation and improved their dispersion within the matrix. The processabilities of PSF/TLCP blends before and after compatibilization were investigated. It was found that the melt viscosities were increased by the addition of PSF-g-MAH, which also gave an evidence of the occurrence of interaction between phases.