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向桦木粉/高密度聚乙烯(HDPE)复合材料中添加白色、黄色和红色着色剂,采用热压成型工艺制备彩色木塑复合材料。研究着色剂种类及含量对木塑复合材料力学性能和表面颜色的影响,同时分别考察彩色木塑复合材料在户外自然老化和紫外光加速老化箱中的老化情况,分析讨论其老化机制。结果表明:添加着色剂可提高木塑复合材料的力学性能,改善材料的外观颜色;木塑复合材料的力学强度和总色差随着色剂用量的增加而逐渐增大,当着色剂用量为3.5wt%时,复合材料的性能达到最佳;木塑复合材料经老化实验后表面褪色明显且力学强度显著降低,但自然老化后其性能下降更明显。这主要是因为木塑复合材料在老化过程中,不仅受到紫外光的照射发生了光降解,而且长期被雨水冲刷导致材料表面的桦木纤维及着色剂大量剥落,降低了材料界面结合强度,从而导致材料性能明显下降。 相似文献
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对我国新型木塑复合材料的研究进展进行概括和评述,指出了进一步深入研究发泡木塑复合材料的重要性。重点介绍了聚丙烯基和聚乙烯基发泡木塑复合材料的研究现状;对该领域研究的发展趋势提出了自己的见解。 相似文献
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以麦秸秆粉为填充材料(质量分数50%),以聚丙烯(PP)膜为基体材料,采用混炼模压成型制备麦秸秆/PP木塑复合材料,对其进行紫外线加速老化实验,对比研究不同填充材料的木塑复合材料老化前后的力学性能和颜色变化,用FTIR分析探讨了复合材料老化机制,用SEM观察其表面微观形貌。结果表明,紫外线加速老化会导致麦秸秆/PP复合材料力学性能降低,当老化时间小于960 h时,麦秸秆/PP木塑复合材料弯曲强度、拉伸强度下降幅度较小,老化时间大于960 h时,力学性能下降幅度较大,材料褪色明显; 老化1200 h其弯曲强度、拉伸强度、冲击强度分别下降67.2%、47.89%、32.41%; 麦秸秆纤维中羟基加速了PP的紫外光降解,最终材料表面出现明显裂纹,部分纤维剥落并伴随有PP粉化现象。 相似文献
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合理利用废旧橡塑,可以避免其环境污染,同时也可改良复合材料性能.本研究采用再生高密度聚乙烯(PE-HD)、沙柳木粉和废旧轮胎粉等原材料,通过模压成型制备木橡塑三元复合材料(WRPC).探究不同热氧老化时间作用下WRPC力学性能及耐热性能的变化规律,采用FTIR和SEM分析其老化机理和表面形貌.研究结果表明:热氧老化降低了WRPC的力学性能,老化100 h后,静曲强度、弹性模量、拉伸强度和冲击强度保持率分别为93.40%,84.74%,79.75%和82.63%;储能模量和损耗模量保持率分别为84.34%和89.18%,材料刚性和阻尼性能降低;维卡软化温度和热变形温度先上升后下降,材料抵抗外力变形的能力减弱.FTIR和SEM分析可知,老化过程中WRPC发生了氧化反应,羰基指数先上升后下降,WRPC表面出现了裂纹和孔洞. 相似文献
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采用官能化的聚烯烃树脂代替传统的未改性的聚烯烃树脂,提高了基体树脂的流动性和树脂与木粉之间的界面粘结,从而增强了塑木复合材料的性能。结果表明该材料的性能指标可以通过调整官能化聚烯烃的种类(如PE、PP等)和含量而方便调节。 相似文献
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Estimates of the reliability of wood plastic composites (WPC) are explored for two industrial extrusion lines. The goal of the paper is to use parametric and non-parametric analyses to examine potential differences in the WPC metrics of reliability for the two extrusion lines that may be helpful for use by the practitioner. A parametric analysis of the extrusion lines reveals some similarities and disparities in the best models; however, a non-parametric analysis reveals unique and insightful differences between Kaplan-Meier survival curves for the modulus of elasticity (MOE) and modulus of rupture (MOR) of the WPC industrial data. The distinctive non-parametric comparisons indicate the source of the differences in strength between the 10.2% and 48.0% fractiles [3,183-3,517 MPa] for MOE and for MOR between the 2.0% and 95.1% fractiles [18.9-25.7 MPa]. Distribution fitting as related to selection of the proper statistical methods is discussed with relevance to estimating the reliability of WPC. The ability to detect statistical differences in the product reliability of WPC between extrusion processes may benefit WPC producers in improving product reliability and safety of this widely used house-decking product. The approach can be applied to many other safety and complex system lifetime comparisons. 相似文献
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阻燃型木塑复合材料热解燃烧特性及产物研究 总被引:1,自引:0,他引:1
以改性天然碳水化合物结合碱式硫酸镁晶须(MHSH)混杂纤维为协效剂,结合膨胀阻燃剂(IFR)制备了阻燃型聚丁二酸丁二醇酯(PBS)木纤维复合材料。利用极限氧指数和垂直燃烧测试研究了复合材料的阻燃性能,并采用TG/DTA-MS对复合材料的热解过程、吸放热量和热解燃烧气体产物进行了分析。结果表明,5%的木薯渣作为碳源代替PBS提高了材料的阻燃性能。IFR/木薯渣/MHSH阻燃剂能够有效提高PBS的燃烧初始温度,并缩小燃烧温度范围。阻燃材料燃烧时,首先是IFR受热分解产生不可燃气体氨气在材料表层形成第一层阻燃保护层;其次,材料迅速燃烧产生的炭层形成第二层阻燃保护层;最后,在高温段MHSH分解形成第三层协效阻燃保护层。因此,最终形成了由外层不可燃气体氨气和内层天然碳水化合物MHSH膨胀炭层构成的气-固阻燃屏障,从而有效地提高了复合材料的阻燃性能。 相似文献
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为了充分降低成本,增加环境友好性并获得良好的木质感,以杨木纤维和毛竹纤维为原料,通过挤出成型制备超高填充聚丙烯基木塑复合材料(UH-WPCs)。基于聚丙烯基体含量的大幅降低,对比分析了填充量和木质纤维种类对UH-WPCs高低温力学性能、高低温蠕变性能、热膨胀性能、尺寸稳定性及吸水性能的影响。结果表明,随着填充量从75wt%增加到90wt%,其线性热膨胀系数大幅降低,蠕变应变逐渐减小而在90wt%时增大;拉伸模量和弯曲模量随填充量的增加先升高而后在90wt%时下降;拉伸强度、弯曲强度和冲击强度随着填充量的增加逐渐降低;在低温?30℃时UH-WPCs的拉伸和弯曲性能较高,高温60℃时冲击韧性较好。温度、湿度及含水率变化均导致UH-WPCs尺寸变化,其中厚度方向尺寸变化率最大,其次为宽度方向,长度方向最小,表现出明显的各向异性;湿度对UH-WPCs的尺寸稳定性的影响远大于温度的作用。杨木基UH-WPCs综合性能优于毛竹基UH-WPCs,这与杨木纤维具有更大的长径比及良好的界面结合有关。UH-WPCs的研究为降低WPCs生产成本和拓宽其应用领域提供了理论依据。 相似文献
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Srdjan Dragan Perisic I. Radovic M. Petrovic A. Marinkovic D. Stojanovic P. Uskokovic 《Materials and Manufacturing Processes》2018,33(5):572-579
Poly(ethylene terephthalate) (PET) fibers (virgin, waste, and mixed) were incorporated in the composite poly(methyl methacrylate) (PMMA)–wood. Hybrid composite panels were prepared by pressure molding. Toluene-2,4-diisocyanate (TDI) and (3-mercaptopropyl)trimethoxysilane (MPTMS) were used as cross-linking bonding agents for modification of wood fibers. Influence of cross-linking bonding agents, structure, and composition of PET fibers was examined by studying thermomechanical properties as well as moisture absorption. Moisture absorption was lower for composites with bonding agents. Mechanical testing revealed that the addition of PET fibers drastically enhances properties of the composites. Covalent and hydrogen bonds formed with the addition of bonding agents have also improved mechanical properties compared to the untreated composites. 相似文献
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Numerical and experimental failure analysis of screwed single shear joints in wood plastic composite
In this research, effects of end distances and thicknesses of side and main members on failure loads and also modes of failure of single shear plane joint, made on wood plastic composite (WPC) were studied, both experimentally and numerically as well. Yamada-Sun failure criterion was used to determine failure loads of this kind of joints fabricated on WPC and results were compared with that of experimental observations. Numerical analysis was made by making use of ABAQUS finite element (FE) software. Experiments were conducted according to ASTM D-1037. Predicted failure loads by numerical models were in good agreement with those observed experimentally. Results have indicated that failure load of tested joint is dependent on end distance and thickness of corresponding members as well. Failure modes were determined both by numerical models and tested joints. FE models were used to perform stress analysis. 相似文献