木塑复合材料的力学性能、微观结构与流变性能的研究

以高密度聚乙烯(HDPE)和木粉为原料制备了木塑复合材料。研究了木粉、相容剂含量对木塑复合材料力学性能、流变性能及微观结构的影响。结果表明:木粉含量的增加,可提高复合材料的刚性、熔体黏度以及剪切敏感性,但韧性有所降低;而添加适量的相容剂改善了复合材料的界面微观结构,从而改善了木塑复合材料的力学性能,而且还在一定程度上改善了复合材料的加工流动性。     

CPE对PVC/木粉复合材料动态力学性能及耐热性能的影响

为了增强聚氯乙烯(PVC)基木塑复合材料的动态力学性能,加入氯化聚乙烯(CPE)对复合材料进行改性,并探究CPE对PVC基木塑复合材料性能的影响。采用动态力学分析仪(DMA)和维卡软化温度测试仪,对加入CPE的PVC/木粉复合材料进行测试,分析CPE对PVC/木粉复合材料动态力学性能及耐热性能的影响。结果表明:CPE的加入会对PVC/木粉复合材料的动态力学性能产生重要的影响,且CPE含量约为5份时,复合材料的动态力学性能最佳;但维卡软化温度、热变形温度测试结果显示,CPE的加入降低了PVC/木粉复合材料的耐热性,且随着CPE含量的增加,复合材料的耐热性逐渐减弱。     

助剂对木粉/高密度聚乙烯复合材料成型特性的影响

以双螺杆流变仪制备了木粉/高密度聚乙烯(HDPE)复合材料试样,考察了7种不同加工助剂对木粉/HDPE复合体系成型性能和力学性能的影响。结果表明,不同助剂对木粉分散性和加工能耗影响不同。增塑剂硬脂酸(HSt)可明显提高木粉分散性,乙撑双硬脂酸酰胺(EBS)、硬脂酸锌(ZnSt)和硬脂酸钙(CaSt)等降低木粉分散性。同时,添加增塑剂可有效降低能耗,起到增塑降黏作用。加入马来酸酐接枝聚乙烯(PE-g-MAH)可增强界面结合力,提高木粉分散性,但同时导致加工黏度增大,加工能耗提高。和纯HDPE试样相比,添加了PE-g-MAH的木粉/HDPE复合材料弯曲强度提高31.6%,拉伸强度提高87.2%,而EBS、ZnSt、CaSt、HSt和聚乙烯蜡等润滑剂会导致力学性能有不同程度的降低。研究结果对木塑复合材料加工工艺和配方优化具有实际指导意义。     

PE/PP/木粉复合材料的直接反应增容

通过甲基丙烯酸缩水甘油酯(GMA)、聚乙烯(PE)、聚丙烯(PP)、木粉和其他助剂的熔融挤出,制备了PE/PP/木粉复合材料。通过扫描电镜(SEM)观测了复合材料的冲击断面形貌。利用傅立叶变换红外光谱(FT-IR)分析了复合材料经抽提后所得木粉的组成。测试了复合材料的力学性能和热变形温度(HDT)。研究了苯乙烯(St)和亚磷酸三苯酯(TPP)对反应增容的影响。探索了润滑剂和木粉含量对复合材料性能的影响。结果显示,直接反应增容后,部分树脂分子键合到了木粉表面上,木塑两相的结合力明显增强;复合材料的力学性能和HDT均明显提高。St的加入进一步提高了复合材料的力学性能和HDT;而TPP的加入则导致复合材料的弯曲强度和HDT稍有下降。加入润滑剂后,复合材料的加工性能变好,而拉伸强度、弯曲强度和HDT稍有下降。     

注塑级木塑复合材料的制备与性能研究

本文采用木粉填充聚丙烯,制备了注塑级木塑复合材料,研究了木粉、相容剂及润滑剂对复合材料的吸水率、注塑成型的收缩率以及熔融指数的影响。结果表明,木粉的加入降低了复合材料的流动性与注塑收缩率,但吸水率增加;相容剂能有效降低吸水率;聚乙烯蜡是该体系较优的润滑剂。     

木粉填充HDPE/PVC复合材料的热稳定性及流变行为

以聚磷酸铵(APP)和Al(OH)3为阻燃剂,通过熔融挤出制备了具有阻燃性能的高密度聚乙烯/聚氯乙烯(HDPE/PVC)基木塑复合材料,研究了PVC对木塑复合材料热稳定性及流变行为的影响。热失重分析结果表明:APP和PVC均可促进木粉成炭,同时提高了HDPE的热稳定性;流变测试结果表明:PVC与木粉的相容性较HDPE要好,并能促进木粉在体系中均匀分散,改善木塑复合材料体系的加工流动性;锥形量热测试结果表明:PVC脱氯、Al(OH)3热分解均吸收大量热量,可降低复合材料的热释放速率与热释放总量。     

木塑原材料摩擦系数的测定及其对挤出加工的影响

测定了高密度聚乙烯(HDPE)、木粉及HDPE/木粉混合物与钢板在20℃下的摩擦系数,并测定了HDPE/木粉混合物在不同温度下与钢板的摩擦系数,分析了摩擦系数对木塑复合材料挤出加工的影响,为深入开展木塑复合材料的挤出加工研究提供了实际可靠数据.     

木质填料种类及含量对木塑复合材料性能的影响

研究了木质填料的种类和含量对木塑复合材料性能的影响。实验发现:随着木粉、竹粉含量的提高,复合材料的拉伸强度、维卡软化温度、弯曲强度和弯曲模量都得到了较大幅度的提高,冲击强度、断裂伸长率和熔体流动速率有所下降。不同粒径和不同种类的木质填料对复合材料的力学性能也有明显的影响,以100目木粉制得复合材料的性能最好,DSC实验数据分析表明:木粉、竹粉含量的变化对复合材料体系的熔融温度有影响;SEM扫描冲击断口形貌表明:相容剂能够有效改善木粉与HDPE界面的相容性,提高界面黏合力,从而使复合材料的性能得到提高。     

塑料基体中MAPE/HDPE比例对木塑复合材料力学性能的影响

以高密度聚乙烯(HDPE)和马来酸酐接枝聚乙烯(MAPE)共混物为塑料基体,以木粉为填料,用注塑成型法制备木塑复合材料,研究MAPE/HDPE质量比变化对塑料基体和木塑复合材料力学性能的影响.结果表明:MAPE/HDPE比变化对MAPE/HDPE共混形成的塑料基体强度基本没有影响,但对由该共混物所制得的木塑复合材料的强度影响显著;在相同的木粉含量下,保持配方中MAPE和HDPE的总含量不变,木塑复合材料的拉伸强度随MAPE/HDPE比率增大先迅速增加,然后趋于平缓.冲击强度随MAPE/HDPE比增大逐渐减小.     

木粉的碱化处理对木塑复合材料性能的影响

采用木粉填充高密度聚乙烯（HDPE）制备复合材料。为增强亲水性的木粉和憎水性的HDPE基质之间的化学亲和力,对木粉碱化处理。研究了相容剂用量和木粉的碱化处理对复合材料力学性能的影响。结果显示,马来酸酐接枝HDPE可明显提高复合材料的力学性能．表现出很好的增容效果：与用未碱化处理的木粉填充的复合材料相比,木粉的碱化处理使复合材料的弯曲强度和弯曲模量分别下降20．4％和36．2％：在不使用相容剂的情况下,木粉的碱化处理也会使复合材料的拉伸强度下降．但在使用适量相容剂后．则可使复合材料的拉伸强度从未处理时的30．3MPa提高到36．5MPa,与纯HDPE相比,拉伸强度提高了44.8％。     

HDPE-g-MAH增容HDPE/木粉复合材料的制备及加工设备的研究

使用HDPE-g-MAH做增容剂,通过双螺杆挤出机制备了HDPE/木粉复合材料,对HDPE-g-MAH进行量变实验,通过力学性能测试确定了最佳用量,并利用SEM对材料微观形貌进行了观察。在此基础上又采用单螺杆挤出机、开炼机和密炼机等不同的加工设备分别制备了木塑复合材料,对力学性能进行了对比表征。结果表明:HDPE-g-MAH的加入很好地改善了木塑复合材料的界面相容性、力学性能和木粉的分散性,HDPE-g-MAH的最佳用量为5份;而且只有使用剪切效果优良的双螺杆挤出机才能制备出性能优异的木塑复合材料。     

甲基化木粉与PE-g-MAH对木粉/HDPE复合材料力学性能的协同作用研究

主要研究了木粉表面甲基化改性和增容剂马来酸酐接枝聚乙烯(PE-g-MAH)对木粉/高密度聚乙烯(HDPE)复合材料力学性能的协同作用。木粉经表面甲基化处理后,与10%PE-g-MAH协同使用,甲基化木粉/PE-g-MAH/HDPE复合材料的拉伸强度、弯曲强度和冲击强度均明显高于未改性木粉/PE-g-MAH/HDPE复合材料,其原因在于在PE-g-MAH的作用下,甲基化木粉在聚合物基体中分布更加均匀,两者的界面作用力更高,即甲基化木粉和PE-g-MAH对提升木粉/HDPE复合材料的力学性能具有良好的协同作用。     

木粉/聚丙烯复合材料力学性能及结晶行为研究

研究了木粉/聚丙烯复合材料的力学性能,结晶行为和微观结构.在木粉含量很高的情况下材料保持很好的拉伸强度,而材料的韧性随着木粉含量的增加下降很大.增容剂MA-PP的加入对材料的拉伸强度很很大的提高,而对冲击强度的影响不大.木粉/PP复合材料的结晶温度随着木粉含量的增加而增大,表明木粉对PP有异相成核的作用.复合材料电镜照片显示木粉在树脂中即使在较高含量下也分散均匀,马来酸改性聚丙烯(MA-PP)的加入提高木粉与树脂基体的界面结合.     

Wood‐thermoplastic composites from wood flour and high‐density polyethylene

High‐density polyethylene/wood flour (HDPE/WF) composites were prepared by a twin‐screw extruder. The effects of WF, silane coupling agents, polymer compatibilizers, and their content on the comprehensive properties of the WF/HDPE composites have been studied in detail, including the mechanical, thermal, and rheological properties and microstructure. The results showed that both silane coupling agents and polymer compatibilizers could improve the interfacial adhesion between WF and HDPE, and further improve the properties of WF/HDPE composites, especially with AX8900 as a compatibilizer giving higher impact strength, and with HDPE‐g‐MAH as a compatibilizer giving the best tensile and flexural properties. The resultant composite has higher strength (tensile strength = 51.03 MPa) and better heat deflection temperature (63.1°C). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Rheological properties of teak wood flour reinforced HDPE and maize starch composites

Teak wood flour reinforced high density polyethylene and maize starch composites were prepared by using maleic anhydride grafted polyethylene as a compatibilizer. The mechanical properties (tensile and flexural) of all the composites increased after addition of 10%–40% teak wood flour into HDPE matrix. The complex viscosity (η*) was higher for all the composites at the low frequency, but decreased with increasing frequencies indicating a shear thinning behavior of the composites. The storage modulus and loss modulus increased for the composites compared to the HDPE at low frequencies. Damping factor peak of HDPE and composites showed high below 1 Hz, but the peak start decreasing with increasing above 1 Hz. The relaxation behavior of HDPE and the composites after incorporating teak wood flour, maize starch, and compatibilizer was obtained by Han plot. Biodegradability was enhanced with the incorporation of teak wood flour, maize starch into the composites. Appreciable water uptake and the thickness swelling for the composites indicating it's potential for interior, automobile and packaging applications.     

硅烷偶联剂对HDPE/木粉复合材料性能的影响

使用经硅烷偶联剂HP-172和HP-174改性的木粉制备了HDPE/木粉复合材料,研究了偶联剂用量对其性能的影响。实验结果表明:当使用1.5%的HP-172处理木粉后,可使复合材料的各项力学性能提高30%以上;HP-174的用量为1%~1.5%也得到了较好的改性效果。通过FIR和SEM分析发现,硅烷偶联剂可与木粉表面发生化学反应,从而提高了HDPE与木粉的界面粘合强度,使复合材料的力学性能得以提高     

Studies on the Thermal and Mechanical Properties of Foamed Wood-Polymer Composites

Wood flour-polypropylene foamed composites, in ratios of 10:90, 20:80, 30:70, and 40:60 (wt./wt.), were prepared with and without maleic anhydride treatment of wood flour and maleic anhydride-grafted PP (MAgPP). The effects of the amount of wood flour and its treatment on the morphology, the mechanical properties, and the thermal properties of the composites were investigated. Vicat softening temperatures (VST) were recorded as 112.9°C, 103.2°C, and 96.2°C for MAgPP wood flour (MPP), maleic anhydride-treated wood flour (MWF), and untreated wood flour (UWF) (40:60 wt./wt.) foamed composites, respectively. The heat distortion temperatures (HDT) were measured to be 80°C, 76°C, and 58°C for the respective composites. DSC thermograms showed an increase in the crystallinity of MPP and MWF composites with an increase in the ratio of wood flour in the composite, whereas the opposite trend was observed in untreated wood flour. Except for impact strength and flexural strength, Young's modulus, flexural modulus, and hardness all increased with an increase in wood flour content. The micrographs confirmed the foaming. The improvement in the properties of the composites is due to the increment in interfacial bonding between polymer and wood flour, which is caused by the compatibilizers.     

Effect of compatibilizing agents on the mechanical properties of high‐density polyethylene/olive husk flour composites

The main objective of this research was to investigate the effect on the thermal and mechanical properties of the addition of two different compatibilizing agents, malefic anhydride‐grafted polyethylene (PE) [synthesized in a solution state (MAPE) and commercial (XA255)], to olive husk flour, high‐density polyethylene (HDPE) composites. The composites contain 30 wt % of olive husk flour and a variable proportion of compatibilizer (3, 5, and 7 wt %). The grafting reaction was followed by Fourier transform infrared, and the grafting degree was evaluated by means of titration. The effect of grafting on the thermal properties of MAPE was observed by ATG/DTG. The mechanical and thermal properties of the composite were investigated. A morphological study of the composite reveals that there is a positive effect of compatibilizing agent on interfacial bonding. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013