SG增容PA6/sPS共混体系的形态结构与力学性能

采用一系列不同甲基丙烯酸环氧丙酯(GMA)含量的苯乙烯-甲基丙烯酸环氧丙酯共聚物(SG)增容尼龙6(PA6)/间规聚苯乙烯(sPS)(80/20)共混物,通过扫描电镜及拉伸实验考察了SG共聚物中GMA的含量对共混物形态结构及力学性能的影响。形态观察显示,SG共聚物可以有效地降低PA6/sPS共混物中分散相的尺寸,增加两相界面间的粘接力;SG共聚物中GMA的含量对其增容效果有较大影响,质量分数为5%左右时,SG共聚物对PA6/sPS共混物的增容效果最佳。拉伸实验结果表明,PA6/sPS共混物的拉伸强度及模量随着SG共聚物的加入而增加,但其断裂伸长率在较高SG含量时则有所下降。     

聚碳酸酯/尼龙6共混体系力学性能的研究

探讨了不同增容剂对PC／PA共混体系的影响，研究结果表明：苯乙烯－马来酸酐共聚物（SMA）对PC／PA共混体系有一定增容作用，加入少量SMA后，共混物的力学性能有所提高；自制增容剂B与SMA协同使用对PC／PA共混体系有较好增容作用，协同增容后共混物的冲击强度大幅度提高，同时共混物仍保持较高的拉伸强度和弯曲强度。     

极性可调高聚物接枝氧化石墨烯相容剂的制备及在MC尼龙中的应用

设计制备了极性可调控的反应型相容剂乙烯-辛烯共聚物-甲醛缩多乙烯多胺-g-氧化石墨烯(POE-TEPAF-GO),并将其应用于铸型尼龙(MC尼龙)/马来酸酐接枝乙烯-辛烯共聚物(MAPOE)共混体系中。同时,调节TEPAF相对分子质量大小,考察不同极性的相容剂对共混材料MC尼龙/MAPOE的影响。研究结果表明,POE-TEPAF-GO对MC尼龙/MAPOE共混体系增容效果较为理想,并且可作为多功能填料对共混材料实现增韧和增强,其中共混材料韧性提高最为显著,较纯MC尼龙提高93%,拉伸强度、热稳定性也有所改善,此外在一定程度上改变了晶型。当TEPAF的Mw=931时,材料的综合性能最优。     

反应增容PA6/PBT共混体系聚集态结构与力学性能

通过熔融共混制备了SMA增容的PA6/PBT共混物,研究了增容剂对PA6/PBT共混体系聚集态结构及力学性能的影响。研究表明,SMA能有效地提高PA6/PBT共混体系两相间的相容性,降低分散相尺寸,使分散相分布均匀,同时有效地提高了共混体系的力学性能。通过对试样进行热处理,探讨了不同热处理温度对PA6/PBT共混合金力学性能的影响。结果表明,热处理能提高共混物的拉伸强度,但导致共混物的缺口冲击强度下降。     

SMA增容剂对PA6/PP合金性能影响和增容机理研究

采用苯乙烯接枝马来酸酐无规共聚物(SMA)作为增容剂,制备PA6/PP合金.研究了PA6/PP配比和SMA增容剂用量对合金热力学性能和吸水性的影响.实验结果表明:SMA对PA6/PP共混体系有很好的增容作用,当PA6/PP/SMA质量比为90/10/(2～4)时,合金综合性能最好,其中材料热变形温度、缺口冲击强度提高很大,吸水率下降明显.对合金的微观结构进行了分析,并对增容机理进行探讨.     

CSW/POE-g-MA/PA6三元复合材料的结构和性能

采用马来酸酐接枝乙烯一辛烯共聚物(POE-g-MA)对CaS04晶须/尼龙6(CSW/PA6)共混物增韧改性,研究了csw/PA6和CSW/POE-g-MA/PA6复合材料的力学性能、热性能、形貌和加工性能.适量添加CSW可同时提高PA6的刚性和韧性.与纯PA6性能比较,10％CSW/PA6的拉伸强度、弯曲强度、弯曲模量和冲击强度分别增大7.5％、9.1％、21.1％和11.6％;当CSW含量增至30％,CSW/PA6的韧性明显降低.POE-g_MA可促进PA6基体中csw的均匀分散,增强CSW与PA6的界面粘附,提高CSW/PA6 (30/70)的冲击韧性.源于CSW和POE-g-MA的协同作用,CSW/POE-g-MA/PA6 (30/5/65)的冲击强度和弯曲模量与纯PA6相比较,分别提高了36.8％和22.1％,拉伸和弯曲强度接近纯PA6.     

CSW/POE-g-MA/PA6三元复合材料的结构和性能

采用马来酸酐接枝乙烯-辛烯共聚物(POE-g-MA)对CaSO4晶须/尼龙6(CSW/PA6)共混物增韧改性,研究了CSW/PA6和CSW/POE-g-MA/PA6复合材料的力学性能、热性能、形貌和加工性能。适量添加CSW可同时提高PA6的刚性和韧性。与纯PA6性能比较,10%CSW/PA6的拉伸强度、弯曲强度、弯曲模量和冲击强度分别增大7.5%、9.1%、21.1%和11.6%;当CSW含量增至30%,CSW/PA6的韧性明显降低。POE-g-MA可促进PA6基体中CSW的均匀分散,增强CSW与PA6的界面粘附,提高CSW/PA6(30/70)的冲击韧性。源于CSW和POE-g-MA的协同作用,CSW/POE-g-MA/PA6(30/5/65)的冲击强度和弯曲模量与纯PA6相比较,分别提高了36.8%和22.1%,拉伸和弯曲强度接近纯PA6。     

尼龙6/聚乳酸共混物的结构及性能

采用熔融共混法制备了尼龙6/聚乳酸(PA6/PLA)共混物,探索性研究了聚乳酸(PLA)部分替代尼龙6(PA6)的可行性。通过力学性能测试、扫描电镜(SEM)形态观察和热稳定性分析,研究了共混物的性能。研究结果表明,当PLA的含量不超过30%时,PA6/PLA共混物的拉伸强度在纯PA6拉伸强度的96%以上,拉伸模量是纯PA6的1.16～1.6倍;维卡软化点在173℃以上,热稳定性良好;形态观察发现共混物中PA6和PLA两相界面结合紧密,具有良好的相容性。而当PLA的含量超过40%时,PA6/PLA共混物的拉伸强度和热稳定性明显降低。     

EPDM-g-MAH对PPO/PA6共混体系结构与性能的影响

通过双螺杆熔融反应挤出,获得了马来酸酐化的三元乙丙橡胶(EPDM-g-MAH),并将其与聚苯醚(PPO)、尼龙6(PA 6)共混,制备了PPO/PA 6/EPDM三元共混合金。研究了弹性体EPDM-g-MAH中MAH用量以及EPDM-g-MAH用量对PPO/PA 6共混体系力学性能和相态结构的影响。结果表明:EPDM-g-MAH中MAH用量在1%~2%范围内,可显著改善EPDM与PPO/PA 6共混体系的相容性,大大提高共混合金的韧性;在三元共混体系中,随着弹性体EPDM-g-MAH用量的增加,冲击强度和断裂伸长率提高,但拉伸强度降低。     

UHMWPE/PA1010塑料合金的制备及性能

采用共辐照接枝法合成UHMWPE-g-AA接枝共聚物;采用共混技术制备UHMWPE/PA1010合金。以UHMWPE-g-AA接枝共聚物作为UHMWPE/PA1010合金增容剂。由于PA1010与UHMWPE-g-AA有较强的相互作用,UHMWPE/PA1010合金的冲击强度和断裂伸长率提高,韧性得到改善;同时,这种相互作用限制了A1010的结晶,使PA1010中正常的结晶含量减少,结晶温度升高。SEM结果表明,增容作用使基体与分散相间界面张力减小,粘结性增强,从而使分散相的粒子尺寸减小,分布更加均匀,拉伸断面显示明显的牵拉现象。共混体系的摩擦系数与纯PA1010相比明显降低,摩擦时在 PA1010表面形成完整UHMWPE的润滑膜,使磨耗量减小,摩擦系数降低。     

Effect of montmorillonite on the morphologies and properties of monomer casting polyamide 6/polystyrene blends via successive in situ polymerization

Monomer casting polyamide 6 (MCPA6)/polystyrene (PS)/montmorillonite (MMT) ternary composites were prepared via successive in situ polymerization. The effects of Na⁺-MMT and OMMT on morphologies of MCPA6/PS blends have been studied by scanning electron microscopy (SEM) and transmission electronic microscopy (TEM). Incorporation of certain amount of Na⁺-MMT results in the diameter of PA6 dispersed microspheres in PS matrix increased significantly from several to dozens of micrometers. It was interesting to find that all Na⁺-MMT was dispersed only in the MCPA6 microspheres. However, a different morphology was observed in MCPA6/PS blend with incorporation of OMMT, especially when the content of OMMT ≥1 wt%. That is, the morphologies of the ternary blends change from dispersed PA6 microspheres/PS matrix to dispersed PA6 network with inclusion of local PA6 microspheres/PS matrix. It was surprising that OMMT dispersed in PA6 microspheres at low OMMT loading (i.e., 0.5 wt%), while OMMT was dispersed in PA6 network phase, not in PA6 microspheres phase at high OMMT loading (i.e., ≥1 wt%). The incorporation of a various amount of MMT affected the crystallization behavior of PA6 phase in the MCPA6/PS blends by the results of XRD and DSC. The MMT layers leaded to the co-existence of α-crystalline form and γ-crystalline form of PA6. Furthermore, the more the MMT contents, the stronger the intensity of the γ-peak. Another interesting phenomenon was that there was a remarkable difference in molecular weight of PA6 microspheres phase and PA6 network phase in MCPA6/PS/OMMT (2 wt%) ternary composites from GPC results.     

热致液晶共聚酯/PA6/RSMA原位复合材料1.RSMA对热致液晶共聚酯/PA6共混体系的增容作用

选用Vectra A950热致液晶共聚酯（LCP）,制备热致液晶共聚酯（LCP）／聚酰胺6（PA6）／苯乙烯－马来酸酐无规共聚物（RSMA）三元共混物,采用注射成型的方法实现原位复合,测定复合材料的熔体流变性能,FTIR光谱,动态力学性质和共混物形态结构,研究了RSMA对聚酰胺6／热致液晶共聚酯共混体系的增容作用,结果表明,RSMA的加入提高了LCP／PA6共混体的熔体粘度：RSMA与LCP和PA6发生酯化,酰胺化反应,改善了LCP与PA6之间的相容性,使两者的玻璃化温度相互靠近,了LCP在PA6基体中的分散,增强了两者之间的界面粘接。     

Preparation of micron-sized PA6/12 copolymer microspheres via successive in-situ polymerization

Micron-sized polyamide 6/12 (PA6/12) copolymer microspheres were firstly synthesized via successive in-situ polymerization of styrene (free radical polymerization), equimolar Laurolactam (LL) and Caprolactam (CL) (anionic ring-opening polymerization). The resulting PA6/12 microspheres were regular sphericity, with diameter ranging from 9.2 to 138.0 microns and narrow size distribution (size distribution ranging from 1.2 to 3.3), as confirmed by scanning electron microscopy (SEM) and Laser diffraction size Analyzer. Furthermore, the study on the PA6/12 microspheres in PA6/12 and PS (PA6/12/PS) blends confirmed that the particle size distribution, diameter of PA6/12 microspheres were controllable, and closely related to the content of PS in the blends, which indicated that the formation of the PA6/12 microspheres in the PA6/12/PS blends can be elucidated via a phase inversion mechanism.     

液晶聚合物对尼龙1010/聚丙烯共混合金的结晶行为和力学性能的影响

用DSC研究了液晶聚合物（LCP）的含量对PA1010／聚丙烯（PP）共混合金结晶和熔融行为的影响：用TGA研究了共混合金的热稳定性：用拉伸试验检测共混材料的力学性能。结果表明：PA1010／PP共混合金中加入0．6％－0．8％（质量）LCP时能起微纤增强和异相成核剂作用,提高合金结晶温度和结晶度,使结晶完善程度略有增加,结晶速率略受影响,并且共混材料的拉伸强度明显增强,但对其热稳定性影响不大。当LCP含量增加到5％时,将作为独立组分在共混合金中起作用,使PA1010和PP的结晶峰均出现明显分峰现象,共混材料的力学性能和热稳定性显著下降。     

热致液晶共聚酯/PA6/RSMA原位复合材料2.力学性质与破坏行为

选用Vectra A950热致液晶共聚酯（LCP）制备热致液晶共聚酯（LCP）/聚酰胺6（PA6）/苯乙烯-马来酸酐无规共聚物（RSMA）三元共混物。并注射成型制得复合板材。研究三元LCP/PA6/RSMA原位复合材料的形态结构、力学性质和破坏行为。结果表明,PSMA是LCP/PA6复合材料的有效增容剂。RSMA的加入有利于LCP在PA6基体中原位成纤,增强了两相之间的界面粘接。加入RSMA后,LCP/PA6原位复合材料的杨氏模量、抗拉强度和抗冲击强度明显提高。RSMA能延长LCP/PA6复合材料的裂纹引发时间、增加裂纹引发能和总冲击能。对LCP/PA6原位复合材料有增韧作用。RSMA的加入量存在一临界值。     

Structure formation and miscibility of sheets from PBT and LCP blends

Sheets from blends containing poly(butylene terephthalate) (PBT) and liquid crystalline polymer (LCP) were prepared using a twin-screw extruder. The LCP used is a copolymer composed of 20 mol % ethylene terephalate (PET) and 80 mol % p-hydroxybenzoic acid (PHB). Thermal behavior, viscoelastic properties, and structure of the sheets of various compositions were investigated by using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), microwave orientation analysis (MOA), and wide angle x-ray diffraction (WAXD). X-ray diffractograms of extruded sheets from PBT, LCP, and their blends show a high degree of orientation along extrusion direction. The orientation is mainly due to the high crystallization rate of PBT, although crystallization and orientation of PBT in the PBT and LCP blends could also be induced by adding LCP. In the PBT and LCP blends, the thermal properties of the constituents are slightly changed indicating that PBT and LCP are partially miscible. DSC measurements show that as the amount of LCP added to the blend increased, the melting point T _m of PBT in the blends decreased. The single glass transition temperature T _g for the PBT and LCP was observed by DMA. Furthermore, no evidence of transesterification in PBT and LCP blends was observed by WAXD.     

The role of functionalized carbon nanotubes in a PA6/LCP blend

Multi-walled carbon nanotubes (MWCNTs) were carboxyl-functionalized in order to improve their dispersion in a polymer matrix. The carboxyl-functionalized MWCNTs (i.e., MWCNT-COOH) were added into a blend matrix consisting of polyamide 6 (PA6) and liquid crystalline polymer (LCP) (PA6:LCP = 80:20 in weight) to make ternary composites. The effects of MWCNT-COOH on the rheological, physical, morphological, thermal, mechanical, and electrical properties of the ternary composites have been examined systematically. The dispersion of MWCNTs in the polymer matrix and their interactions with the polymers (i.e., PA6 and LCP) were found to be the most important factors affecting all properties. The functionalization of MWCNTs resulted in the significant improvement in their dispersion in the polymer matrix and largely enhanced the interactions of MWCNTs with the polymer matrix. The functionalized MWCNTs acted not only as reinforcement fillers but also as a compatibilizer that could enhance the interfacial adhesion between PA6 and LCP. Interestingly, the packing density of the polymer matrix was greatly increased by adding MWCNT-COOH.     

Performance characteristics of compatibilized ternary Nylon 6/ABS/LCP in-situ composites

Ternary Nylon 6/poly(acrylonitrile-butadiene-styrene)(ABS)/liquid crystalline polymer (LCP) blends compatibilized by the maleic anhydride-grafted polypropylene (MAP) and solid epoxy resin (bisphenol type-A) were injection molded. Thermoplastic matrix consisting of Nylon 6/ABS (60/40) (wt%) was melt blended with various LCP (Vectra A950) contents. The effects of compatibilizer additions on the structure-mechanical property relationship of the in-situ composites reinforced with LCP were investigated. SEM observation revealed that the additions of epoxy and MAP compatibilizers to the Nylon 6/ABS/LCP blend were very effective to enhance the interfacial adhesion of its phase components. Consequently, extended long and fine LCP fibrils were formed in the skin section of in-situ composites. Tensile measurements revealed that uncompatibilized Nylon 6/ABS/LCP blend exhibited lower strength, stiffness and impact toughness. However, the incorporation of MAP and epoxy resin compatibilizers into Nylon 6/ABS/LCP blend improved its tensile strength, stiffness and impact toughness considerably. This was due to the compatibilizers effectively promoted stress transfer at the interfacial phase regions of ternary in-situ composites. The compatibilized composites exhibited mechanical anisotropy, especially for the tensile strength. Thermogravimetric measurements showed that the heat resistance and heat stability of the in-situ composites tended to increase with increasing LCP content.     

The effects of temperature and liquid crystalline polymer (LCP) on mechanical properties of a blend of polyphenylene sulphide and LCP

The mechanical properties of polyphenylene sulphide (PPS) and liquid crystalline polymer (LCP) blends were investigated over a range of temperatures. The effect of blend composition on the brittle-ductile transition temperature (B-D) was also studied by differential scanning calorimetry and scanning electron microscopy. Blends of various compositions (PPS/LCP; 90/10, 75/25, 50/50 and 25/75) were prepared and injection moulded. The bending test temperature was varied between –40 and 150 °C. The results showed a rapid load drop at the B-D transition region. The B-D transition temperature occurred in unannealed pure PPS, 90/10, 25/75 and 50/50 blends around 75 °C whilst in the annealed sample it was observed around 100 °C. In pure LCP and 25/75, no transition occurred. Partial miscibility of PPS and LCP was confirmed by SEM observations, bending modulus and thermal properties. The use of LCP, as a good reinforcing agent which can improve processability and modulus, is discussed.     

PVDF、LCP及其共混物的流变行为

研究了ＰＶＤＦ、ＬＣＰ的表观粘度随温度,剪切速率的变化规律,并对液晶含量对共混物熔体度的影响进行了讨论。