PP-g-MA和UP增容PP/玻璃纤维复合材料性能的研究

以聚丙烯-马来酸酐接枝(物PP-g-MA)和不饱和聚(酯UP)作为界面相容剂,研究了界面相容剂对玻璃纤维增强PP复合材料力学性能及界面黏结的影响。结果表明:加入PP-g-MA或UP,玻璃纤维增强PP复合材料的力学性能明显提高,且UP的增容效果优于PP-g-MA。在玻璃纤维含量为40%时,PP/UP/GF复合材料的拉伸强度比未改性的复合材料的拉伸强度提高了150%,弯曲强度提高了132%,冲击强度提高了89%;扫描电镜照片表明:PP-g-MA和UP使被拔出玻璃纤维表面黏附了一层树脂,增强了PP与玻璃纤维之间的界面黏结作用;DSC测试表明:PP-g-MA和UP同时加入使复合材料熔融峰温度下降结,晶度增加。     

反应挤出PP/LGF复合材料的制备及性能

采用熔融浸渍工艺制备了长玻纤增强聚丙烯复合材料,研究了接枝单体GMA、MA以及引发剂DCP含量对长玻璃纤维增强聚丙烯复合材料力学性能的影响。结果表明:与采用接枝单体GMA相比,采用接枝单体MA反应挤出PP/LGF复合材料的力学性能对引发剂DCP的用量更为敏感,严重影响了PP/LGF复合材料的力学性能;当引发剂DCP质量分数为0.1%,采用接枝单体MA反应挤出PP/LGF复合材料性能最优,并且与没有添加相容剂的PP/LGF复合材料相比,拉伸强度、冲击强度分别提高31%、50%。     

高接枝率PP-g-MAH的制备及其在PP/GF中的应用

对传统双螺杆反应挤出机进行工艺改进,研究了辅助接枝单体和不同半衰期引发剂的分段加入工艺对马来酸酐熔融接枝聚丙烯（PP-g-MAH）的影响。结果表明,辅助接枝单体的提前加入能够有效抑制MAH接枝PP过程中的大分子自由基的断裂;不同半衰期引发剂的分段加入起到良好的协同作用,大幅度提高MAH的接枝效率并有效降低其残留;在30 %玻璃纤维增强PP体系（PP/GF30）中,通过该工艺制备的相容剂在1.6 %的添加量时与通用PP-g-MAH相容剂3 %添加量时的力学性能相近;较低的添加量和MAH残留不仅能够改善最终制品的颜色和气味,还可以提高制品的热稳定性。     

PP/PA6/OMMT纳米复合材料制备及其振动力场下发泡性能研究

利用复合引发剂(过氧化二异丙苯/过氧化苯甲酰)自制马来酸酐接枝聚丙烯(PP g MAH)作为相容剂,制备了聚丙烯/聚酰胺6/马来酸酐接枝聚丙烯/纳米有机黏土（PP/PA6/PP g MAH/OMMT）复合材料,研究了相容剂和纳米OMMT含量对复合体系力学性能的影响,并利用自制超临界CO2塑料动态发泡实验装置,研究了发泡温度、转子转速、振动力场对复合材料发泡性能的影响。结果表明,在复合材料配比为PP/PA6/PP g MAH/OMMT=100/30/15/3时,与纯PP相比,复合材料的熔体强度提高了163 %,冲击强度提高了41 %,拉伸强度提高了8.4 %;在剪切力场上叠加振动力场,有助于改善泡孔形状,均化泡孔分布,提高泡孔密度。     

玻纤毡增强聚丙烯复合材料的增容及力学性能

通过玻璃纤维(GF)毡与双螺杆挤出相容剂改性聚丙烯(PP)膜的多层叠合,以熔融浸渍法制得PP基GF毡增强热塑性塑料(GMT)复合材料,研究了相容剂PP接枝马来酸酐(PP-g-MAH)和PP接枝丙烯酸(PP-g-AA)的用量(为PP基体质量的百分数)及其复配改性,以及相容剂改性PP基体分布和毡体种类对GMT力学性能的影响。结果表明,PPg-MAH可明显提高GMT的拉伸与弯曲性能,但降低了冲击性能;PP-g-AA可明显提高GMT的冲击性能,但不利于拉伸与弯曲性能的提高,只有当PP-g-AA用量超过5%后,拉伸性能才有所提升。在PP-g-MAH用量为3%的条件下,将其与不同用量的PP-g-AA进行复配改性没有对GMT力学性能产生协同作用。在各相容剂用量相近(3%~3.5%)的情况下,与相容剂复配改性GMT相比,以两层PP-g-AA改性PP为芯层、PP-g-MAH改性PP为上下表面层作为改性基体分布时,GMT拉伸与弯曲强度分别提高17%和27%、缺口冲击强度提高48%;而以两层PP-g-MAH改性PP为芯层、PP-g-AA改性PP为上下表面层作为改性基体分布时,在不损失强度与刚性的同时,缺口冲击强度提高了88%。采用连续GF毡的GMT力学性能比采用短切GF毡的GMT高,尤其是缺口冲击强度提高了89.6%。     

以助交联剂为第二单体的聚丙烯熔融接枝反应

以助交联剂三烯丙基异氰尿酸酯(TAIC)或三聚氰酸三烯丙酯(TAC)作为聚丙烯(PP)熔融接枝马来酸酐(MAH)过程中的第二单体制备PP-g-MAH,与苯乙烯、丙烯酸、甲基丙烯酸甲酯等常用的第二单体进行了对比,对其反应机理进行了探讨;以TAIC为例,研究了其用量对PP-g-MAH接枝率、熔体流动速率(MFR)等性能的影响。结果表明,与苯乙烯等第二单体相比,以助交联剂TAIC或TAC为第二单体,制备的PP-g-MAH接枝率更高,MFR更低,且未产生刺激性气味;在MAH用量不变的条件下,当TAIC用量(占PP-g-MAH中PP质量的百分数)由0%增加至0.5%时,接枝率由0.36%增至0.85%,MFR由95.7 g/10 min降至38.2 g/10 min。将制备的PP-g-MAH应用于PP/玻璃纤维(GF)复合材料和PP/尼龙(PA)6合金中,结果表明,随TAIC用量增加,两种材料的力学性能整体提高,TAIC用量以0.5%为宜。在PP/GF/PP-g-MAH质量比为70/30/0.7或PP/PA6/PP-g-MAH质量比为20/70/10时,与未加TAIC的相比,PP/GF复合材料的冲击强度、弯曲强度和弯曲弹性模量分别提升了10.9%,20.8%和17.7%,PP/PA6合金的断裂伸长率、冲击强度、弯曲强度和弯曲弹性模量分别提升了42.9%,8%,12.9%和8.8%。     

PP-g-MAH/改性高岭土复合材料的制备与性能

利用γ-氨丙基三乙氧基硅烷偶联剂(KH550)对高岭土(kaolin)进行表面改性,制备了改性kaolin(M-kaolin),然后将聚丙烯(PP)接枝上顺丁烯二酸酐(MAH),制备了PP-g-MAH,将两者经过熔融共混制备了PP-gMAH/M-kaolin复合材料,研究了M-kaolin添加量对复合材料力学性能和热稳定性的影响。结果表明,当M-kaolin粒子质量分数为1%时,PP-g-MAH/M-kaolin复合材料的拉伸强度和断裂伸长率达到最大值,与纯PP相比分别提高了10.4%和122%;当M-kaolin粒子质量分数为2%时,复合材料的缺口冲击强度达到最大值,较纯PP提高了96.5%,且热稳定性最好。这表明kaolin粒子经KH550改性且PP经MAH接枝后,PP与kaolin相容性得到优化,从而使复合材料的强度和韧性都得到了提高。     

离聚物的制备及其在PP/EVA复合材料中的应用研究

以马来酸钠(MANa)为接枝单体,过氧化二异丙苯(DCP)为引发剂,采用熔融接枝的方法,利用聚丙烯(PP)接枝MANa制备了离聚物MANa接枝PP(PP-g-MANa),并对其结构进行了表征,发现MANa与PP发生了接枝反应。将接枝率为29.1%的PP-g-MANa引入到PP/乙烯-醋酸乙烯酯(EVA)复合材料中,探讨了离聚物对复合材料力学、加工性能及微观结构的影响。结果表明,PP-g-MANa可作为PP/EVA复合材料的相容剂;当其用量为8份时,复合材料的拉伸强度和弯曲强度分别提高了3.2,3.9MPa,冲击强度提高了12.3kJ/m2,同时,熔体流动速率提高了76.6%。     

熔融浸渍及界面结合对连续玻璃纤维增强聚丙烯复合材料性能的影响

熔融浸渍技术一直是制备连续玻璃纤维增强聚丙烯复合材料的主流技术。然而,聚丙烯熔体流动性低、黏度高以及树脂与玻璃纤维相容性较差的问题限制了它的广泛应用。针对这些技术难题,一方面,采用负载了2,5-二甲基-2,5-二(叔丁基过氧基)己烷的聚丙烯粒子(MB-CR PP)为断链剂,提高聚丙烯流动性;另一方面,使用相容剂马来酸酐接枝聚丙烯(PP-g-MAH)来改善连续玻璃纤维增强聚丙烯复合材料的界面结合强度。结果表明,使用MB-CR PP能够降低聚丙烯分子量,大幅提高其流动性,可以使熔融树脂与玻璃纤维浸渍更加充分,并降低连续玻璃纤维增强聚丙烯复合材料的孔隙率,从而在一定程度上改善复合材料的力学性能。当MB-CR PP在树脂体系中含量为0. 4%时,复合材料的力学性能达到最优。进一步提高其用量会明显降低聚丙烯的力学性能,从而导致复合材料力学性能下降。此外,当相容剂用量从0%增加到2. 5%时,复合材料的界面结合强度明显改善,力学性能也有较大提高,但进一步提高相容剂用量对复合材料力学性能的改善效果就不明显。     

马来酸酐熔融接枝EVA增韧EVA阻燃复合材料

以马来酸酐(MAH)为接枝单体、过氧化二异丙苯(DCP)为引发剂,采用熔融接枝制备了乙烯-醋酸乙烯酯接枝马来酸酐共聚物(EVA-g-MAH).将接枝率为2.20%的EVA-g-MAH作为EVA/氢氧化镁(MH)/微胶囊化红磷(MRP)复合材料的相容剂,探讨了相容剂对复合材料力学、阻燃、加工性能和微观结构的影响.结果表明,当EVA-g-MAH用量为12份时,复合材料的冲击强度达30.3 kJ/m2,拉伸强度由8.7 MPa提高到了12.9 MPa.在力学性能得到改善的同时,复合材料的垂直燃烧级别仍可达到FV-0,氧指数由33.5%提高到了34.8%,复合材料熔体流动速率为3.3 g/10 min.     

The effect of epoxy and tetramethyl thiuram disulfide on melt‐grafting of maleic anhydride onto polypropylene by reactive extrusion

In this report, melt grafting of maleic anhydride (MAH) and epoxy resin onto polypropylene (PP) by peroxide‐initiated reactive extrusion has been investigated. As evidenced by Fourier transform infrared spectroscopy, both MAH and epoxy resin were successfully grafted onto PP through the reactions of MAH with PP and epoxy resin with MAH. It was found that tetramethyl thiuram disulfide could promote the grafting of MAH and inhibit the degradation of PP, as revealed by chemical titration and melt flow experiments, through prolonging the lifetime of the macroradical; meanwhile, epoxy resin could reduce the sublimation of MAH and the maximum grafting degree of MAH. Furthermore, the introduction of grafted products was found to enhance the mechanical properties of PP/glass fiber composites, and this influence was very significant at high grafting degrees with a high content of epoxy resin, which could be interpreted in terms of improved compatibility and adhesion at the interface. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43422.     

MAH/St固相接枝聚丙烯对聚丙烯/滑石粉复合材料性能的影响

利用马来酸酐（MAH）/苯乙烯（St）共单体固相接枝聚丙烯（MSP）作增容剂,采用熔融共混和注塑成型的方法制备了PP/滑石粉复合材料,研究了MSP对PP/滑石粉复合材料热行为、拉伸强度和动态力学性能的影响.结果显示MSP降低了PP/滑石粉复合材料中PP相的熔融温度（Tm）,但随着增容剂MSP含量的增加,Tm呈上升趋势.MSP改善了PP/滑石粉间的相容性,促进了滑石粉的异相成核作用,提高了PP相的Tco随着MSP含量的提高,Tc呈下降趋势.MSP增容剂提高了PP/MSP/滑石粉复合材料的拉伸强度和动态贮能模量,并存在一最佳的增容剂添加量.     

马来酸酐/二乙烯基苯接枝聚乳酸对微晶纤维素/聚乳酸复合材料性能的影响

研究了马来酸酐(MAH)/二乙烯基苯(DVB)接枝聚乳酸(PLA-g-DVB/MAH)对微晶纤维素(MCC)/聚乳酸(PLA)复合材料性能的影响。首先采用熔融接枝法,将DVB作为MAH的共聚单体接枝到PLA分子链上制备PLA-g-DVB/MAH接枝聚合物,然后以PLA-g-DVB/MAH为相容剂,采用注射成型法制备MCC/PLA复合材料。利用FTIR对PLA-g-DVB/MAH进行表征,探究了PLA-g-DVB/MAH对MCC/PLA复合材料流变及力学性能的影响。结果表明,MAH成功接枝到PLA上,并得到接枝聚合物PLA-g-DVB/MAH;添加PLA-g-DVB/MAH后,MCC/PLA复合材料的储能模量、复数黏度、平衡扭矩以及剪切热都有明显升高;PLA-g-DVB/MAH的添加有利于改善MCC和PLA的界面相容性,进而提高了MCC/PLA复合材料的力学性能。     

Crystallization behavior of PP/PP‐g‐MAH/GFR PA66 blends: Establishment of their continuous‐cooling‐transformation of relative crystallinity diagrams

Polypropylene/polypropylene‐grafted‐maleic anhydride/glass fiber reinforced polyamide 66 (PP/PP‐g‐MAH/GFR PA 66) blends‐composites with and without the addition of polypropylene‐grafted‐maleic anhydride (PP‐g‐MAH) were prepared in a twin screw extruder. The effect of the compatibilizer on the thermal properties and crystallization behavior was determined using differential scanning calorimetry analysis. The hold time was set to be equal to 5 min at 290°C. These conditions are necessary to eliminate the thermomechanical history in the molten state. The crystallization under nonisothermal conditions and the plot of Continuous‐Cooling‐Transformation of relative crystallinity diagrams of both PP and PA 66 components proves that PP is significantly affected by the presence of PP‐g‐MAH. From the results it is found that an abrupt change is observed at 2.5 wt % of PP‐g‐MAH as a compatibilizer and then levels off. In these blends, concurrent crystallization behavior was not observed for GFR PA66. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1620–1626, 2007     

Effect of maleic anhydride‐grafted polypropylene on polypropylene/recycled acrylonitrile butadiene rubber/empty fruit bunch composite

The effect of maleic anhydride‐grafted polypropylene (PP‐g‐MAH) as a compatibilizer on the properties of polypropylene (PP)/recycled acrylonitrile butadiene rubber (NBRr)/empty fruit bunch (EFB) composites were studied. The composites were melt mixed using a heated two roll mill at 180°C and a speed of 15 rpm with six different compositions (100/0/10, 80/20/10, 70/30/10, 60/40/10, 50/50/10, 40/60/10 phr). The effects of PP‐g‐MAH on mechanical, morphological and chemical properties of the PP/NBRr/EFB composites were examined. The PP‐g‐MAH compatibilized composites have higher tensile values compare to uncompatibilized composites. Scanning electron microscopy showed better adhesion between EFB and PP/NBRr matrices in the presence of PP‐g‐MAH. Better interaction was formed between EFB and PP/NBRr matrices via C‐O‐C ester bonds as indicated by FTIR analysis. J. VINYL ADDIT. TECHNOL., 24:275–280, 2018. © 2016 Society of Plastics Engineers     

Biodegradable biocomposites from poly(butylene adipate‐co‐terephthalate) and miscanthus: Preparation,compatibilization, and performance evaluation

Miscanthus fibers reinforced biodegradable poly(butylene adipate‐co‐terephthalate) (PBAT) matrix‐based biocomposites were produced by melt processing. The performances of the produced PBAT/miscanthus composites were evaluated by means of mechanical, thermal, and morphological analysis. Compared to neat PBAT, the flexural strength, flexural modulus, storage modulus, and tensile modulus were increased after the addition of miscanthus fibers into the PBAT matrix. These improvements were attributed to the strong reinforcing effect of miscanthus fibers. The polarity difference between the PBAT matrix and the miscanthus fibers leads to weak interaction between the phases in the resulting composites. This weak interaction was evidenced in the impact strength and tensile strength of the uncompatibilized PBAT composites. Therefore, maleic anhydride (MAH)‐grafted PBAT was prepared as compatibilizer by melt free radical grafting reaction. The MAH grafting on the PBAT was confirmed by Fourier transform infrared spectroscopy. The interfacial bonding between the miscanthus fibers and PBAT was improved with the addition of 5 wt % of MAH‐grafted PBAT (MAH‐g‐PBAT) compatibilizer. The improved interaction between the PBAT and the miscanthus fiber was corroborated with mechanical and morphological properties. The compatibilized PBAT composite with 40 wt % miscanthus fibers exhibited an average heat deflection temperature of 81 °C, notched Izod impact strength of 184 J/m, tensile strength of 19.4 MPa, and flexural strength of 22 MPa. From the scanning electron microscopy analysis, better interaction between the components can be observed in the compatibilized composites, which contribute to enhanced mechanical properties. Overall, the addition of miscanthus fibers into a PBAT matrix showed a significant benefit in terms of economic competitiveness and functional performances. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45448.     

Effects of the chemical foaming agents,injection parameters,and melt‐flow index on the microstructure and mechanical properties of microcellular injection‐molded wood‐fiber/polypropylene composites

Wood‐fiber‐reinforced plastic profiles are growing rapidly in nonstructural wood‐replacement applications. Most manufacturers are evaluating new alternative foamed composites, which are lighter and more like wood. Foamed wood composites accept screws and nails better than their nonfoamed counterparts, and they have other advantages as well. For example, internal pressures created by foaming give better surface definition and sharper contours and corners than nonfoamed profiles have. In this study, the microfoaming of polypropylene (PP) containing hardwood fiber was performed with an injection‐molding process. The effects of different chemical foaming agents (endothermic, exothermic, and endothermic/exothermic), injection parameters (the mold temperature, front flow speed, and filling quantity), and different types of PP (different melt‐flow indices) on the density, microvoid content, physicomechanical properties, surface roughness, and microcell classification of microfoamed PP/wood‐fiber composites were studied. A maleic anhydride/polypropylene copolymer (MAH‐PP) compatibilizer was used with the intention of improving the mechanical properties of microfoamed composites. The microcell classification (from light microscopy) and scanning electron micrographs showed that an exothermic chemical foaming agent produced the best performance with respect to the cell size, diameter, and distance. The polymer melt‐flow index and the variation of the injection parameters affected the properties and microstructure of the microfoamed composites. The density of the microfoamed hardwood‐fiber/PP (with a high melt‐flow index) composites was reduced by approximately 30% and decreased to 0.718 g/cm³ with an exothermic chemical foaming agent. Tensile and flexural tests were performed on the foamed composites to determine the dependence of the mechanical properties on the density and microvoid content of the foamed specimens, and these properties were compared with those of nonfoamed composites. MAH‐PP improved the physicomechanical properties up to 80%. With an increase in the mold temperature (80–110°C), the surface roughness was reduced by nearly 70% for the foamed composites. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1090–1096, 2005     

Effects of clay contents on the dynamic mechanical and rheological properties of polypropylene/MAH‐g‐POE/clay composites

A series of polypropylene/maleic anhydride grafted polypropylene octane elastomer (MAH‐g‐POE)/clay (PPMC) nanocomposites were prepared with a novel compatilizer MAH‐g‐POE and different contents of octadecyl amine modified montmorillonite, and the effects of clay contents on the dynamic mechanical and rheological properties of these PPMC composites were investigated. With clay content increasing, the characteristic X‐ray diffraction peak changed from one to two with intensity decreasing, indicating the decreasing concentration of the intercalated clay layers. The gradual decrease of crystallization temperature of PPMC composites with the increase of clay loading should be attributed to the preferred intercalation of MAH‐g‐POE molecules into clay interlayer during blending, which is also reflected by scanning electron microscopy observations. By evaluating the activation energy for the glass transition process of MAH‐g‐POE and polypropylene (PP) in the PPMC composites, it is found that clay intercalation could cause the restriction effect on the glass transition of both MAH‐g‐POE and PP, and this restriction effect appears stronger for PP and attained the highest degree at 5 wt % clay loading. The melt elasticity of PP could be improved apparently by the addition of MAH‐g‐POE, and 5 wt % clay loading is enough for further enhancing the elastic proportion of PP. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

马来酸酐及苯乙烯同时接枝聚丙烯的研究

用过氧化二异丙苯(DCP)作为引发剂，采用双螺杆反应挤出的苯乙烯、马来酸酐2种单体同时接枝聚丙烯．研究了单体总浓度、单体比例、引发剂浓度对PP的接枝率、接枝效率和熔体流动速率的影响。通过实验发现苯乙烯的加入使接枝率和接枝效率比单独的马来酸酐接枝都有很大的提高。     

Effect of maleic anhydride/vinyltrimethoxysilane‐co‐grafting polypropylene on the properties of wood‐flour/polypropylene composites by electron‐beam preirradiation

The electron‐beam preirradiation and reactive extrusion technologies were used to prepare maleic anhydride (MAH)/vinyltrimethoxysilane (VTMS)‐co‐grafting polypropylene (PP) as a high‐performance compatibilizer for wood‐flour/PP composites. The grafting content, chemical structure, and crystallization behavior of the compatibilizers were characterized through Fourier transform infrared spectroscopy, differential scanning calorimetry, and an extraction method. The effects of the compatibilizers on the mechanical properties, water absorption, morphological structure, and torque rheological behavior of the composites were investigated comparatively. The experimental results demonstrate that MAH/VTMS‐g‐PP markedly enhanced the mechanical properties of the composites. Compared with MAH‐g‐PP and VTMS‐g‐PP, MAH/VTMS‐g‐PP clearly showed synergistic effects on the increasing mechanical properties, water absorption, and compatibility of the composites. Scanning electron microscopy further confirmed that the adhesion and dispersion of wood flours in the composites were effectively improved by MAH/VTMS‐g‐PP. These results were also proven by the best water resistance of the wood‐flour/PP composites with MAH/VTMS‐g‐PP. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011