木粉填充HDPE的力学性能

以木粉对ＨＤＰＥ填充改性为实验研究对象,初步探讨了表面处理和填充量对木粉填充改性ＨＤＰＥ力学性能的影响。     

HDPE—g—MAH至HDPE／CaCO3填充体系的增容作用

通过熔融接枝的方法制备了高分子型界面相容剂ＨＤＰＥ－ｇ－ＭＡＨ并将其应用于ＨＤＰＥ／ＣａＣＯ３填充体系;考查了ＨＤＰＥ－ｇ－ＭＡＨ对ＨＤＰＥ／ＣａＣＯ３俭朴 间的界面粘连,是使材料实现强韧化的关键组分。     

PE—g—MAH对HDPE／PA6共混合金的增容作用

利用ＤＳＣ研究了ＰＥ－ｇ－ＭＡＨ对ＨＤＰＥ／ＰＡ６共混体系的增容作用,并讨论了ＰＥ－ｇ－ＭＡＨ对ＨＤＰＥ／ＰＡ６共混物的混容性能和力学性能的影响。结果表明：ＰＥ－ｇ－ＭＡＨ能有效地增强ＨＤＰＥ／ＰＡ６共混体系两相界面的相互作用,改善ＨＤＰＥ和ＰＡ６的相容性,是效果较好的增容剂。适量的ＰＥ－ｇ－ＭＡＨ的加入可使ＨＤＰＥ／ＰＡ６共混合金的可混性能提高,并有一定的增强作用。     

工艺条件对HDPE／PA—6共混体系形态结构影响的研究

通过测试ＨＤＰＥ、ＰＡ－６的流变性能和对共混物进行显微镜法（ＰＣＭ）分析,研究了加工温度和剪切速率等工艺条件对ＨＤＰＥ／ＰＡ－６共混形态结构的影响。结果表明：改变加工温度可以调节ＨＤＰＥ／ＰＡ－６共混组成粘度比。ＰＡ－６和ＨＤＰＥ的粘讧比较大时,ＰＡ－６相呈层状分布结构,剪切作用有利于共混体系两相的分散,剪切速率过低易使ＰＡ－６相区尺寸大,分散不均匀。较高的剪切速率使ＰＡ－６相尺寸减小,分散更均匀     

木粉填充聚乙烯的研究

研究了木粉粒度，木粉填充量以及采用不同表面处理剂处理木粉对聚乙烯（ＰＥ）力学性能和加工性能的影响，并做了阻燃性木粉填充塑料复合材料的探索试验。     

LLDPE—氢氧化镁复合材料性能研究

研究了偶联剂种类及用量与以线型低密度聚乙烯（ＬＬＤＰＥ）为基体的复合材料ＬＬＤＰＥ－Ｍｇ（ＣＨ）２的力学性能关系；同时考察了处理与未处理的氢氧化镁对复合体系力学性能及阻燃性能影响。结果表明，经表面处理的Ｍｇ（ＯＨ）２填充到ＬＬＤＰＥ中，其复合体系的分散性、力学性能、流动性均优于未处理的ＬＬＤＰＥ－Ｍｇ（ＯＨ）２复合体系，且关剂对Ｍｇ（ＯＨ）２的表面改性处理，主要改善了材料的力学性能，对阻燃性能影响     

马来酸酐接枝EPDM及对尼龙的改性

讨论了以来酸酐熔融接枝ＥＰＤＭ的制备工艺、反应机理及ＭＡＨ－ｇ－ＥＰＤＭ的接枝率，分别了ＭＡＨ－ｇ－ＥＰＤＭ与尼龙的相容性及对尼龙力学强度的影响。结果表明添加少量ＭＡＨ－ｇ－ＥＰＤＭ可显著提高尼龙的韧性。     

PA－66／（PE／EPDM）－g－MAH共混增韧的研究

本文研究了尼龙－６６（ＰＡ－６６）与聚乙烯（ＬＤＰＥ）共混物的力学性能。结果表明，用马来酸酐接枝聚乙烯和三元乙丙橡胶（ＥＰＤＭ）改善了与基体ＰＡ－６６的相容性。添加弹性体ＥＰＤＭ，使之生成（ＰＥ／ＥＰＤＭ）－ｇ－ＭＡＨ共聚物，可以大幅度度地提高ＰＡ－６６／（ＰＥ／ＥＰＤＭ）－ｇ－ＭＡＨ冲击强度，同时熔体粘度随温度的变化趋于平缓，吸水率有所下降。     

一种新型的填料透闪石在HDPE中的应用研究

本文主要介绍了把一种新型的填料透闪石通过偶联剂处理后填加到ＨＤＰＥ中去，研究了其主要的力学性能，热性能，加工性能的变化规律，并与ＣａＣＯ３粉煤灰填充ＨＤＰＥ后的复合材料性能进行了对比，证实了可行性。     

透闪石填充HDPE的研究

介绍了把一种新型的填料透闪石通过偶联剂处理后填加到ＨＤＰＥ中去，研究了其主要的力学性能，热性能，加工性能的变化规律，并与ＣａＣｏ３、粉煤灰填充ＨＤＰＥ的复合材料性能进行了对比，证实了可行性。     

几种木质纤维的热稳定性能的研究

近十年来,我国生产的各种木塑复合材料大多采用木粉、稻糠为主要原料,其他木质纤维在木塑复合材料中的应用研究甚少。本文对松木粉、稻糠、竹粉、稻草纤维和麦秸纤维等5种木质纤维的热稳定性能及其在PE基木塑复合材料中的应用效果进行了对比研究。研究表明:5种木质纤维的热稳定性能相近,所得HDPE基木塑复合材料的物理机械性能也相近,均可用于制备PE基木塑复合材料。     

The effects of nanoclay on the extrusion foaming of wood fiber/polyethylene nanocomposites

This article presents the foaming behaviors of wood fiber/high density polyethylene (HDPE) composites with small amounts of nanoclay. Melt compounding is used to prepare two types of clay‐filled wood fiber composites: intercalated and exfoliated clay composites. Their respective morphologies are determined using wide‐angle X‐ray diffraction (XRD) and transmission electron microscopy (TEM). We subsequently conduct an extrusion foaming experiment of the composites using N₂ as the blowing agent. Varying the wood fiber content, as well as the processing parameters, such as temperature and pressure, the effects of different amounts of clay and the degree of exfoliation on the final cell morphology and the foam density of the wood fiber/HDPE/clay nanocomposite foams are studied. The results suggested that the addition of nanoclay improved the cell morphology of the wood fiber/HDPE composite foams as its content and degree of dispersion increased. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers     

Microcellular foam of polymer blends of HDPE/PP and their composites with wood fiber

In this study, the effects of batch processing conditions (foaming time and temperature) and blend composition as well as the effect of incorporating wood fiber into the blends on the crystallinity, sorption behavior of CO₂, void fraction, and cellular morphology of microcellular foamed high‐density polyethylene (HDPE)/polypropylene (PP) blends and their composites with wood fiber were studied. Blending decreased the crystallinity of HDPE and PP and facilitated microcellular foam production in blend materials. The void fraction was strongly dependent on the processing conditions and on blend composition. Foamed samples with a high void fraction were not always microcellular. The addition of wood fiber inhibited microcellular foaming. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2842–2850, 2003     

Creep resistance of wood‐filled polystyrene/high‐density polyethylene blends

Creep, the deformation over time of a material under stress, is one characteristic of wood‐filled polymer composites that has resulted in poor performance in certain applications. This project was undertaken to investigate the advantages of blending a plastic of lower‐creep polystyrene (PS) with high‐density polyethylene (HDPE) at ratios of 100:0, 75:25, 50:50, 25:75, and 0:100. These various PS–HDPE blends were then melt blended with a short fiber‐length wood flour (WF). Extruded bars of each blend were examined to measure modulus of elasticity and ultimate stress. Increasing the ratio of WF increased modulus of elasticity in all composites, except between 30 and 40% WF, whereas the effect of WF on ultimate stress was variable, depending on the composite. Scanning electron microscopic images and thermal analysis indicated that the wood particles interacted with the PS phase, although the interactions were weak. Finally, creep speed was calculated by using a three‐point bending geometry with a load of 50% of the ultimate stress. Creep decreased only slightly with increasing WF content but more significantly with increasing PS content, except at pure PS. The WF/75PS–25HDPE blend showed the least creep. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 418–425, 2001     

杨木纤维表面改性及其HDPE复合材料性能研究

利用过氧化物作为引发剂,加入马来酸酐偶联把聚乙烯蜡接枝到杨木纤维表面上。接枝前后木纤维的红外光谱和色散自由能的显著变化证实了接枝反应的发生,并通过一系列实验计算了反应的接枝率;随着反应温度的提高,接枝率呈上升趋势,在170％以上变化趋势变缓。与未改性的木纤维相比,改性后木纤维填充HDPE复合材料的力学性能有较大提高,其拉伸、弯曲、冲击强度可分别提高34．9％,29．2％和8．8％,但随着聚乙烯蜡接枝量的增大,材料力学性能又有所下降。扫描电镜照片显示改性木纤维在基体中分散更均匀,界面结合良好。     

CHARACTERIZATION OF MICROCELLULAR FOAMED POLYOLEFIN BLEND COMPOSITES WITH WOOD FIBER

The effects of wood fiber content on the void fraction, cell morphology, and notched Izod impact strength of microcellular foamed HDPE/PP blend composites with wood fiber were studied. The influence of wood fiber content on the carbon dioxide adsorption and desorption in the samples was also examined. Adsorption of carbon dioxide decreased with increased wood fiber content. Gas diffusion rates were faster as wood fiber content increased. The void fraction decreased dramatically when wood fiber was introduced in the blend. Environmental scanning electron microscopy (ESEM) was used to investigate the effects of wood fiber content on cell morphology. The 30:70 HDPE/PP polymer blend without wood fiber resulted in a high void fraction, with a uniform and well-developed microcellular structure, but when wood fiber was introduced, a uniform and well-developed microcellular structure could not be produced. The effects of foaming on Izod impact strength were dependent on wood fiber content.     

短纤维／弹性体复合材料的研究──SF－（Rr－Rs）／HDPE复合材料研究

研究了短纤维（ＳＦ）增强再生胶（Ｒｒ）、废胶粉（Ｒｓ）与高密度聚乙烯（ＨＤＰＥ）的橡塑共混体的制备及其性能。讨论了短纤维组分、品种、增容体系及Ｒｓ组分等对多元复合材料基本力学性能的影响．该复合材料具有较高强度、低成本，还具有较好的热塑性。     

聚乙烯蜡表面改性及对木粉/HDPE复合材料性能影响

利用过氧化物作为引发剂,把马来酸酐接枝到聚乙烯蜡上。接枝前后聚乙烯蜡的红外光谱变化证实了接枝反应的发生。与未改性的聚乙烯蜡相比,改性后聚乙烯蜡填充木粉/HDPE复合材料的平衡扭矩和力学性能提高,其拉伸、弯曲、冲击强度分别提高71%、47%和70%,但随着改性聚乙烯蜡添加量的增加,材料的力学性能又有所下降。扫描电镜照片显示改性聚乙烯蜡填充的复合材料,木粉在基体中分散均匀,界面结合良好。     

Recycling of rigid polyurethane foam: Micro-milled powder used as active filler in polyurethane adhesives

Rigid polyurethane (PUR) foams are widely used as heat insulation material in construction industry or for electronic appliances manufacturing. After finishing their life-time, it is necessary to eliminate foam wastes. The aim of this study was to prepare a pair of industrial PUR adhesives of medium viscosity containing recycled rigid PUR foam. Three methods of milling were tested: knife-milling, two-roll milling, and ball-milling. Only two-roll milling gives the PUR micro-powder usable for following adhesives modification. The micro-powder was used as passive filler in PUR adhesives and potential reactivity for polyol pack replacement was studied. Hydroxyl and amine numbers were determined in mixture with virgin polyol. One-component PUR prepolymer adhesive was prepared using various dosages of the micro powder and the tensile strength of bound wood was measured. As additional parameters, also free film adhesive mechanical parameters were tested and particle size distribution of the micro powder was analyzed. Two adhesive formulations were prepared for independent evaluation of the micro powder reactivity. The results showed growing of the mechanical strength of wood bonding with growing dosage of the micro powder.     

Structure and adhesion properties of acrylic acid grafted high‐density polyethylene powders synthesized by a novel photografting method

A novel photografting, nonvapor, and nonliquid phase living graft polymerization was developed to functionalize high‐density polyethylene (HDPE) powder. The structure and adhesion properties of HDPE powder grafted with acrylic acid (AA) were studied by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), water contact angle, peel strength, and graft degree measurements. The result shows that HDPE powder can be grafted with AA via the method with a short reaction time and a high monomer conversion. The graft degree increases with the reaction time. Then, the hydrophilicity of the grafted HDPE powder increases also. The peel strength of HPDE/steel joint improved significantly when acrylic acid grafted HPDE powder was used as hot melt adhesive in place of ungrafted HDPE powder. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008