温度对两种木塑复合材料的影响

在众多环境因素中,温度是对木塑复合材料性能影响最显著的因素之一.在一定温度范围内,木塑复合材料的抗弯性能随温度的升高而降低.     

木塑复合材料的研究

木塑复合材料,是以高分子材料中的热塑性树脂为母体,加入木材纤维素和木质素,以及多种化学助剂,经高温混炼而成的一种新型复合材料。它可代替木材和部分金属,广泛用于各个领域。1 国内外对木塑复合材料的研究与进展60年代初,世界各国就开始了木塑复合材料的研究,产品刚一问世,即受欢迎,取     

剑麻纤维/聚丙烯木塑复合材料耐磨性能研究

采用熔融共混、模压成型方式制备剑麻纤维(SF)/聚丙烯(PP)木塑复合材料,探讨剑麻纤维对复合材料耐磨性能的影响;考察SF的表面处理方式、用量以及同玻璃纤维(GF)混杂增强与复合材料耐磨性能的关系;通过扫描电镜(SEM)对复合材料磨损的表面形态结构进行了研究。结果表明:SF的表面处理方式和用量对材料耐磨性能有一定影响;SF与GF混杂后材料的耐磨性能随SF用量的增加而增加;纯PP树脂的摩擦以磨粒磨损和粘着磨损为主,SF/PP复合材料磨损以磨粒磨损为主,SF/GF/PP复合材料的磨损是磨粒磨损和粘着磨损共同承担的结果。     

木塑复合材料的蠕变和应力松弛性能研究

木塑复合材料在实际使用时,较高的温度会显著影响其各种力学性能。通过研究在一定温度条件下木塑材料的蠕变和应力松弛性能可知,在产品中加入增强筋或改进产品配方等可有效减少木塑复合材料的蠕变和应力松弛。     

木塑复合材料阻燃技术研究现状和趋势

综述了近年来木塑复合材料的常用阻燃剂类型（主要指无卤阻燃剂）、阻燃处理工艺及其阻燃性能的研究现状,对木塑复合材料的燃烧性能进行了分析,并结合木塑复合材料在阻燃方面存在的问题对其未来发展方向进行了展望。     

木塑复合材料的表面润湿性研究

热塑性聚合物之间的熔融共混改性和木材纤维与热塑性聚合物之间的复合,加入偶联剂均可提高复合材料的润湿性,对材料的相容有利;在偶联剂加入量相同的情况下,增加木材纤维的用量可以加速材料的润湿速度,有利于提高材料的润湿性;在热塑性聚合物用量一定的前提下,改变加入的增强材料的形状,对材料润湿性有影响,木材纤维可以提高复合材料的润湿性.     

木塑复合材料阻燃研究进展

对木塑复合材料(WPC)的阻燃研究进展进行了综合阐述,总结了近几年WPC用阻燃剂及阻燃处理方法的研究成果,并根据研究中存在的问题,着眼于提高阻燃剂的阻燃性及与WPC的相容性,展望了今后木塑复合材料在阻燃剂改性方面的研究方向。     

木塑复合材料成型加工过程中的变色机理及控制研究进展

文章介绍了木塑复合材料的成型方法及发展趋势,主要论述了木塑复合材料成型过程中的变色原因及其控制方法。     

再生木塑复合材料的研究进展

木塑复合材料（WPC）具有比单独的木质材料或塑料产品更优异的性质,是木材的理想代用品。从固体废弃物中分离出木材和塑料进行复合,不仅可以减缓废弃木材和塑料对城市环境的潜在污染,而且也适应了现代材料复合化发展的规律。文中论述了国内外学者在木塑复合材料方面所进行的研究情况及其应用前景和发展趋势。     

木塑复合材料的应用及其发展前景

介绍了木塑复合材料的成分、加工工艺，该材料的适用范围及其力学性能，以及国内外木塑复合材料制品的发展现状和市场前景，为加快我国木塑复合材料产业的发展，提出了三点意见。     

温湿处理环境对木塑复合材弯曲性能的影响

木塑复合材在使用时应考虑不同的环境条件对材料性能的影响,本文研究了不同密度的聚丙烯基木塑复合材经高/低温和浸水处理后材料的弯曲性能的变化情况,为木塑产品的生产和应用提供依据。     

木塑复合材料阻燃改性中的主要影响因素

研究了木塑复合材料阻燃改性中的3个重要因素,即木塑比例、阻燃剂种类和阻燃剂的添加量对其性能的影响。结果表明:木塑比例对材料的综合性能影响最大,木粉与塑料的比例提高时,材料的耐水性能提高,而材料的阻燃性能降低,静曲强度降低;在不同种类的阻燃剂对材料的阻燃性能改性实验中,复合磷氮类阻燃剂效果最佳;阻燃剂的添加实验表明,随着阻燃剂添加的量增加,材料的阻燃性能提高,内结合强度加大,而耐水性能降低。     

Impact of coupling agent on properties of wood-plastic composite

The impact of two coupling agents, maleic anhydride (coupling agent 1) and isocyanate (coupling agent 2) on the properties of wood-plastic composites (WPC) was studied. Wood-plastic composites were made with coupling agents 1 and 2 and properties were tested under the condition that the ratio of wood fiber to thermoplastic polymer was 7:3, target density was 0.7 g/cm³, press temperature was 175°C, press time was 8 min, and adding amount of coupling agent 2%. Results show that coupling agent 2 was superior to coupling agent 1 and had great effect on the physical and mechanical properties of WPC. When using the same coupling agent, the impact on their properties varied with different thermoplastic polymers. Translated from China Forest Products Industry, 2006, 33(4): 30–32 [译自: 林产工业]     

Chemical characterization of smoke from the production process of wood-plastic composites

The chemical composition of unpleasant smell, emitted from the production process of wood-plastic composites using Manchurian ash sawdust (Fraxinus mandschurica Rupr.) and polypropylene powder as the raw material, was investigated. Wood sawdust and polypropylene powder were subjected to heat treatment to 290°C during 8 min (the conditions were similar to those employed on an industrial scale). The emitted compounds were collected and analyzed by gas chromatography-mass spectrometry (GC-MS). The analytical r...     

3种薄木贴面木塑复合材料蠕变性能比较

研究采用薄木贴面木塑复合材料代替实木作为办公家具异型封边材料的适用性。通过分析不同树种对薄木贴面PVC基木塑复合材料静曲强度和蠕变性能的影响规律,确定较佳薄木种类。结果表明:在不同树种的薄木贴面中,抗蠕变性能由大到小依次为:黑胡桃>小鞋木豆>栎木。在一定时间(48 h)内,各组试验样品的最终挠度值随载荷增加而增大。黑胡桃薄木贴面在3种试验材料中最适宜作为办公家具异型封边材料使用。     

The effect of mineral fillers on the thermal properties of wood-plastic composites

Abstract

The thermal properties of wood-plastic composites with five different mineral fillers were studied. The tested mineral fillers were calcite (CaCO₃), two different qualities of wollastonite, soapstone, and talc. The amount of wood, mineral, and plastic (polypropylene) was kept constant. Only the mineral type has been changed during the tests. The thermal behavior of the samples was studied by using a differential scanning calorimeter, a thermogravimetric analyzer and by determining the heat build-up. The analyzed properties were compared with a reference sample made without adding any minerals. The results show that the addition of mineral fillers does not remarkably change the thermal stability of composites. All the studied mineral fillers except soapstone had a small effect on the heat build-up.     

Effects of nanoclay on physical and mechanical properties of wood-plastic composites

Effects of nanoclay (NC) on physical and mechanical properties of wood-plastic composite (WPC) were studied here. Virgin, recycled, and mixed (50/50% of virgin/recycled) polyvinyl chloride (PVC) were used as the matrix in the WPC. Specimens with three NC contents of 1.5%, 3%, and 5% were manufactured; they were then compared with control specimens. Totally, 12 treatments were manufactured. The physical and mechanical properties were measured in accordance with the ASTM standards. The highest properties were found in specimens made from virgin PVC. Addition of recycled PVC resulted in significant decrease in all properties. NC improved all physical and mechanical properties studied in the present research project; the highest properties were observed in specimens with 5% of NC content. The improvement in properties was as a result of formation of bonds between the hydroxyl groups of NC with the wood flour components. It was concluded that NC would significantly improve the properties in all the three PVC types of virgin, recycled, and mixed. From an industrial point of view, it was concluded that mixing virgin and recycled PVC can be recommended not only to decrease production costs, but also to partially solve the problem of PVC residue which are not bio-degradable.     

Preliminary study of the effects of EVA coupling agents on properties of wood-plastic composites

As a hot-melt adhesive, ethylene-vinyl-acetate (EVA) has been used in many industrial applications. But studies of the application of EVA in wood-plastic composites (WPC) are relatively few, so we have investigated the proposition of whether EVA is a suitable coupling agent for WPC or not. The results show that EVA with 8% VA is not a suitable coupling agent, because it reduces the mechanical properties of WPC without any significant effect on its physical properties. With an increase in the amount of wood powder, the mechanical properties of WPC decrease and the ability of water absorption of WPC increases.     

草坪草耐干热低温性能研究

通过测定经干热和低温处理的草坪草样本浸泡液的电导率,结合自然干热、低温条件下的表现,比较冷、暖季型草坪草属间、种间或品种间的耐干热、耐低温性能的差异．结果表明,冷季型草坪草耐干热性能,属间存在着显著差异：羊茅草属＞早熟禾属＞黑麦草属＞翦股颖属;同属的种间大部分也存在着显著差异．暖季型草种中,地毯草、假俭草、狗牙根、细叶结缕草等耐干热性能较为理想;细叶结缕草、黑画眉草、结缕草、鼠尾粟、假俭草等的抗寒性能较强．测试结果与田间观测表现一致,说明测定电导率是检测草坪草耐性的一种简便、快速、有效的方法     

热压温度及板材密度对竹木复合层积材顺纹抗压强度的影响

通过单因变量两因素重复试验,以毛竹竹篾和桦木单板为原料,使用酚醛树脂胶黏剂压制竹木复合层积材,分析热压温度及板材密度对竹木复合层积材顺纹抗压强度的影响。结果表明,在试验选定因素水平范围内,热压温度和板材密度对竹木复合层积材顺纹抗压强度影响显著,板材顺纹抗压强度随热压温度的升高而增强,但145℃与160℃两水平之间差异并不显著;不同密度对板材顺纹抗压强度的影响差异显著,板材的顺纹抗压强度随板材密度的增大而增大;在其他工艺参数相对不变的情况下,热压温度与板材密度的交互作用对板材顺纹抗压强度的影响并无显著的影响。