全生物分解PLA/PPC/改性淀粉共混薄膜拉伸性能的研究

采用溶液共混的方法,用二氧化碳共聚物脂肪族聚碳酸酯(PPC)、改性淀粉对聚乳酸(PLA)改性,制备出韧性得以改善的PLA/PPC/改性淀粉共混薄膜.通过研究共混薄膜拉伸性能与共混组成配比的关系,试验结果表明,加入30%甘油对淀粉进行糊化,对淀粉改性效果较好.随着PPC组分的增加,提高了共混膜的断裂伸长率,增强了其韧性,...     

硅烷化改性木薯淀粉/聚碳酸亚丙酯共混膜的结构及耐水性EI北大核心CSCD

以三甲基氯硅烷(TMCS)对木薯淀粉进行疏水化处理,并通过热压混合法制备了硅烷化改性木薯淀粉/聚碳酸亚丙酯(TMCS-Starch/PPC)共混膜。采用傅里叶变换红外光谱、X射线衍射以及扫描电子显微镜对共混膜进行表征。结果表明,三甲基氯硅烷基团被成功引入到木薯淀粉颗粒表面;热压成型后TMCS-Starch由结晶态转变为无定形态,并与PPC具有明显的氢键作用。研究了共混膜的力学性能和耐水性。结果表明PPC可以明显改善共混膜的韧性和耐水性能,当TMCS-Starch与PPC的质量比为3/7时,共混膜的断裂伸长率达到601.2%,吸水率和淀粉溶出率分别较TMCS-Starch膜降低了17.15%和85.29%。     

基于阻尼特性的淀粉流变相接枝改性

对淀粉进行了流变相接枝改性,测定织造区域内经纱表面浆膜温度,分析了PVA共混浆膜及原淀粉共混浆膜的动态力学行为。结果表明:在经纱表面浆膜的温度28.3-35.1℃范围内PVA共混浆膜的阻尼特性优于原淀粉共混浆膜,其储能模量(400-450 MPa)和耗能模量(25-30 MPa)均远大于原淀粉共混浆膜的储能模量(<50 MPa)和耗能模量(<5 MPa);经流变相接枝改性后,接枝淀粉的储能模量和耗能模量分别达到500-520 MPa和35-40 MPa,分别提高了900%和600%。流变相接枝改性改善了原淀粉共混浆膜的阻尼特性,解决了浆膜脆、硬、落浆落物等问题。     

PLA-PPC-淀粉的溶液共混改性

将聚乳酸(PLA)、糊化淀粉与聚碳酸亚乙酯(PPC)进行溶液共混并浇注成膜,对共混膜的力学性能和热性质进行表征;通过正交试验设计研究三元共混组成、增塑剂种类及用量对PLA增韧增塑改性的影响。结果表明:共混组成对于共混膜的断裂伸长率及拉伸强度均是显著影响因素;正交试验最优方案制得共混膜的断裂伸长率比纯PLA膜增加200.98%,拉伸强度比纯PLA膜降低1.09%;PPC的加入是共混物韧性提高的主要因素,而淀粉对产物的力学性能没有优化;同时,三元共混物的热分解温度比原料树脂提高,热分解速度下降,说明改性产物热稳定性有所提高。     

聚己内酯接枝甲基丙烯酸缩水甘油酯的制备及对聚己内酯/淀粉的增容作用

以过氧化苯甲酰(BPO)为引发剂,甲基丙烯酸缩水甘油酯(GMA)为反应单体,通过熔融接枝反应将GMA接枝到聚己内酯(PCL)上,制备了PCL-g-GMA。以PCL-g-GMA为增容剂,制备了PCL/淀粉/PCL-g-GMA共混物。扫描电镜表明,PCL/淀粉共混物界面粘接力差、淀粉出现团聚。然而加入PCL-g-GMA后,PCL/淀粉/PCL-g-GMA中淀粉分散变得均匀,且淀粉颗粒被PCL包裹,两相界面更加模糊。拉伸实验表明,加入PCL-g-GMA增容剂后,共混物的拉伸强度由(12.3±2.1)MPa增加到(17.0±3.2)MPa,拉伸模量由(4.2±1.8)GPa增加到(5.7±2.9)GPa.断裂伸长率由(210±16)%增加到(803±40)%。     

改性淀粉/聚乳酸共混物的制备

采用接枝共聚-共混法,制备了乳酸接枝淀粉/聚乳酸复合材料.实验表明,淀粉和乳酸进行接枝反应的最佳温度为90℃,最佳反应时间为3h,在此条件下所得接枝共聚物的接枝率最高为31.62%.共混物的形貌分析和性能研究表明,相对于未经改性的淀粉/聚乳酸复合材料,改性淀粉/聚乳酸复合材料的相容性和机械性能得到明显改善.     

聚乳酸固相接枝马来酸酐及与淀粉共混研究

通过固相接枝的方法,合成了聚乳酸与马来酸酐的接枝共聚物PLA-g-MAH,以改善其与淀粉共混物的相容性.研究了不同的接枝工艺条件对共聚物接枝率的影响,并考察了接枝聚乳酸与淀粉熔融共混物的力学性能和热性能.结果表明,在惰性气体环境中,聚乳酸可以和马来酸酐通过过氧化物引发而发生固相接枝反应.固定PLA100份,MAH 5份(质量比)不变,较好的工艺条件是引发剂用量为0.6份,120℃温度下反应1.4～1.6h.接枝聚乳酸与淀粉熔融共混,改善了聚乳酸和淀粉的相容性,提高了共混物的力学性能.     

聚乙烯／淀粉共混物的相界面性质研究

采用了不同的改性剂对淀粉进行了改性，将改性淀粉与聚乙烯共混制备薄膜。用ＴＰＴ方程和Ｋｅｒｎｅｒ－Ｎｉｅｌｓｅｎ方程对聚乙烯／淀粉共混物的界面特性进行了表征，计算出界面相互作用参数和界面层厚度。用扫描电镜研究了改性淀粉的形态。     

聚丙烯/尼龙弹性体复合体系相容性的研究

采用尼龙弹性体(PAE)对PP进行增韧增强改性,同时添加马来酸酐接枝聚丙烯(MPP)来改善PP与PAE的界面相容性。利用扫描电镜(SEM)、差示扫描量热仪(DSC)等手段及力学性能测试,比较研究了MPP对共混物结晶温度及力学性能的影响。结果表明,PAE适用于PP的增韧改性,且增韧效果取决于三元共混体系中MPP的含量;当所含MPP的质量分数达到3%,共混材料界面相容性好,共混物韧性高。     

官能团化碳纤维/热塑性聚氨酯复合泡沫材料的制备及力学性能

采用浓H_3PO_4/浓HNO_3混酸体系对碳纤维(CF)表面进行预处理得到酸化碳纤维,再利用二苯基甲烷二异氰酸酯(MDI)与酸化碳纤维发生接枝反应,制得官能团化碳纤维(MCF)。将其与热塑性聚氨酯(TPU)熔融共混得到MCF/TPU复合泡沫材料。利用红外光谱、X射线光电子能谱、X射线衍射、拉曼光谱和场发射扫描电镜等表征了纤维接枝改性效果和复合材料结构及断面形貌。结果表明,化学接枝使得纤维表面官能团化,并且接枝改性增加了纤维表面的粗糙度及无序程度。从而成功地改善了纤维和TPU基体的界面粘合力和相容性。力学性能分析表明,相比接枝前的CF,MCF可明显提高复合泡沫材料的力学性能,当纤维添加量为3%时,较改性前拉伸强度提高了16.1%,断裂伸长率提高了18.5%,撕裂强度提升了3.2%,回弹性提高了6.7%,压缩永久变形降低了6.9%。     

二异氰酸酯增容聚甲基乙撑碳酸酯/埃洛石纳米管共混复合材料

在聚甲基乙撑碳酸酯/埃洛石纳米管（PPC/HNT）共混体系中加入2,4-甲苯二异氰酸酯（TDI）作为增容剂,通过熔融共混的方法制备了一系列复合材料,并用万能试验机、热重分析仪（TG）及扫描电子显微镜（SEM）研究了复合材料的力学性能、热性能及微观形貌。结果表明,2,4-甲苯二异氰酸酯的加入使复合材料的拉伸强度得到明显提...     

Preparation,characterization and properties of polycaprolactone diol-functionalized multi-walled carbon nanotube/thermoplastic polyurethane composite

Multi-walled carbon nanotubes (MWCNTs) were chemically functionalized to prepare thermoplastic polyurethane (PU) composites with enhanced properties. In order to achieve a high compatibility of functionalized MWCNTs with the PU matrix, polycaprolactone diol (PCL), as one of PU’s monomers, was selectively grafted on the surface of MWCNTs (MWCNT–PCL), while carboxylic acid groups functionalized MWCNTs (MWCNT–COOH) and raw MWCNTs served as control. Both MWCNT–COOH and MWCNT–PCL improved the dispersion of MWCNTs in the PU matrix and interfacial bonding between them at 1 wt% loading fraction. The MWCNT–PCL/PU composite showed the greatest extent of improvement, where the tensile strength and modulus were 51.2% and 33.5% higher than those of pure PU respectively, without sacrificing the elongation at break. The considerable improvement in both mechanical properties and thermal stability of MWCNT–PCL/PU composite should result from the homogeneous dispersion of MWCNT–PCL in the PU matrix and strong interfacial bonding between them.     

Effect of coupling agents on reinforcing potential of recycled carbon fibre for polypropylene composite

Polypropylene (PP) composites reinforced with recycled carbon fibre have been prepared through extrusion compounding and injection moulding. The reinforcing potential of the recycled fibre was increased by improving the interfacial adhesion between the fibre and PP matrix and this was done by the addition of maleic anhydride grafted polypropylene (MAPP) coupling agents. Three MAPP couplers with different molecular weights and maleic anhydride contents were considered. The effects on the mechanical properties of the composite were studied, and scanning electron microscopy (SEM) was used to study the fracture morphology of the tensile specimens. It was observed that with the addition of MAPP the interfacial adhesion was improved as fewer fibres were pulled-out and less debonding was seen. A microbond test was performed and a significant improvement in interfacial shear strength was measured. This resulted in composites with higher tensile and flexural strengths. The maximum strength was achieved from MAPP with the highest molecular weight. Increased modulus was also achieved with certain grades of MAPP. It was also found that the composite impact strength was improved significantly by MAPP, due to a higher compatibility between the fibre and matrix, which reduced crack initiation and propagation.     

MAH改性方法对淀粉/聚乳酸界面相容性的影响

以玉米淀粉和聚乳酸(PLA)为原料,马来酸酐(MAH)为改性剂,通过熔融挤出法制备淀粉/PLA复合材料。研究了MAH分别作为增容剂和淀粉酯化剂这两种改性方法对淀粉/PLA相容性的影响,并对复合材料的熔融加工性能、力学性能和耐水性能进行了测试。X射线衍射(XRD)、扫描电子显微镜(SEM)和热重分析(TGA)结果都证明,MAH与原淀粉先进行干法酯化改性再与PLA复配制得酯化淀粉/PLA复合材料,比MAH作为增容剂直接添加制得原淀粉/MAH/PLA复合材料具有更好的界面相容性。受界面相容性提高程度的影响,酯化淀粉/PLA复合材料的熔融加工性能、拉伸强度、弯曲强度、断裂伸长率和耐水性能都优于原淀粉/MAH/PLA复合材料。     

Mechanical properties of flax fibre/polypropylene composites. Influence of fibre/matrix modification and glass fibre hybridization

The effect of fibre treatments and matrix modification on mechanical properties of flax fibre bundle/polypropylene composites was investigated. Treatments using chemicals such as maleic anhydride, vinyltrimethoxy silane, maleic anhydride-polypropylene copolymer and also fibre alkalization were carried out in order to modify the interfacial bonding between fibre bundles and polymeric matrix. Composites were produced by employing two compounding ways: internal mixing and extrusion. Mechanical behaviour of both flax fibre bundle and hybrid glass/flax fibre bundle composites was studied. Fracture surfaces were investigated by scanning electron microscopy. Results suggest that matrix modification led to better mechanical performance than fibre surface modification. A relevant fact is that silanes or MA grafted onto PP matrix lead to mechanical properties of composites even better than those for MAPP modification, and close to those for glass fibre/PP.     

热塑性聚合物/木纤维复合材料的研究进展

介绍了国内外关于热塑性聚合物／木纤维复合材料界面改性、在加工过程中木纤维的热稳定性以及阻燃性能等方面的研究进展，界面相容剂或偶联剂能大大提高其界面相容性，特别是马来酸酐接枝热塑性聚合物作为界面相容剂更为有效。硅烷偶联剂预处理木纤维表面对提高其热稳定性有一定的作用。     

废纸浆增强HDPE复合材料的力学性能

将废旧瓦楞纸板粉碎制浆,与高密度聚乙烯通过注塑成型制备废纸浆/HDPE复合材料。研究了废纸浆含量,相容剂HDPE-g-MAH和LDPE-g-GMA,加工助剂S-105、TKM-M80和Deoflow A对废纸浆/HDPE复合材料力学性能的影响,通过扫描电镜SEM分析了复合材料的冲击断面,结果表明,HDPE-g-MAH和...     

原位聚合法制备纳米凹凸棒土/聚乳酸复合材料

将凹凸棒土（AT）进行提纯和有机改性后, 采用原位聚合法制备了OAT质量分数为1%、 3%、 5%的纳米凹凸棒土/聚乳酸复合材料（OAT/PLA-x）。采用红外、 扫描电镜、 X射线衍射等对复合材料进行了表征, SEM结果表明, 凹凸棒土粒子在复合材料中实现了均匀稳定分散。复合材料的力学性能和综合热性能测试表明: OAT/PLA-3复合材料的拉伸强度、 弹性模量分别比纯PLA增加98.6%和130.0%; 复合材料的热稳定性明显提高。同时, 复合材料的溶液降解速率也明显加快。      

Electrochemical deposition of polypyrrole on carbon fibres for improved adhesion to the epoxy resin matrix

A method of improving the interfacial bonding between carbon fibre and epoxy resin matrix is developed in the case of continuous electrochemical deposition (ECD) of polypyrrole on carbon fibres. The ECD-treated carbon fibres are characterized by electron spectroscopy for chemical analysis (ESCA), scanning electron microscope (SEM), porous structure analysis and wettability measurements. Furthermore, mechanical evaluation is used to assess the macro-interfacial bonding capability of carbon fibre/epoxy resin composites. It is shown that there is a good interfacial bonding between ECD-treated carbon fibres and the epoxy resin. On the other hand, we also postulate the structure of polypyrrole-coated fibre to explain the bonding mechanism of carbon fibre/epoxy resin composites.     

硅烷偶联剂改性的木粉/P34HB复合包装材料的制备

目的研究硅烷偶联剂KH550含量对木粉/P34HB复合包装材料性能的影响。采用KH550改性木粉,提高与聚(3-羟基丁酸酯-4-羟基丁酸酯)(P34HB)的结合强度,改善复合材料的力学性能和界面相容性。方法以KH550为改性剂,木粉和P34HB为原料,利用共混热压工艺制备改性木粉/P34HB复合材料;通过对复合材料的形貌进行观察,以及傅里叶变换红外光谱(FTIR)、热重分析(TGA)和力学性能分析,研究KH550质量分数不同时对复合材料界面相容性、力学性能和热性能的影响。结果添加KH550后,复合材料的的界面相容性得到改善;FTIR分析表明,KH550已经成功接枝到木粉中;适量的KH550提高了复合材料的热稳定性;复合材料的储能模量增加;复合材料的力学性能也有所提高。此外还得到了最佳的KH550添加量,即质量分数为0.5%。结论 KH550不仅使得木粉与P34HB的相容性得到改善,同时也增强了复合包装材料的力学性能和热性能。