摘要
木塑复合材料因密度大、易蠕变等特点严重限制其在工程结构领域的应用。为解决上述问题,研究以耐水防潮的稻壳/聚氯乙烯发泡复合材料(rice husk-polyvinyl chloride foamed composites,RHPC)(简称为PVC发泡木塑)为表层,单板层积材(laminated veneer lumber,LVL)为芯层,通过自主搭建设计的多元共挤装置制备PVC发泡木塑-LVL共挤复合材料(RHPC-LVL composites,RHPC-LVL)。结果显示,RHPC-LVL的密度约为0.6 g/cm^(3),弯曲强度和弯曲模量分别为102.6 MPa与11.4 GPa,介于RHPC和LVL之间;比弯曲强度与比弯曲模量较表层RHPC分别提高了38.1%和96.7%。相较于未封端处理的样品,经封端处理后的RHPC-LVL耐老化性能大幅提升,6次加速老化后弯曲强度和弯曲模量的保留率分别为63.5%和38.6%。当施加载荷增至30%极限强度时,RHPC-LVL的800 h蠕变应变较LVL提高16.5%,RHPC在30℃和60℃短期蠕变应变较LVL分别提高33%和200%;通过采用典型的蠕变模型对蠕变阶段和恢复阶段分别进行拟合,为RHPC-LVL在工程领域应用中的蠕变预测提供理论基础。本研究为RHPC-LVL的开发和应用提供指导。
Traditional wood plastic composites(WPC)are extremely limited in engineering structural applications due to their high density and susceptibility to creep behavior.To address these issues,this study developed a composite using a water-resistant,moisture-proof rice husk-polyvinyl chloride foamed composite(RHPC)as the surface layer and laminated veneer lumber(LVL)as the core layer,via a custom-designed co-extrusion device.The resulting RHPC-LVL composites(RHPC-LVL)exhibited a density of approximately 0.6 g/cm³,with a flexural strength of 102.6 MPa and a flexural modulus of 11.4 GPa,falling between those of RHPC and LVL.Compared to the surface RHPC,the specific flexural strength and specific flexural modulus of RHPC-LVL increased by 38.1%and 96.7%,respectively.After end-capping treatment,the aging resistance of RHPC-LVL was significantly improved,with flexural strength and flexural modulus being 63.5%and 38.6%of the control specimens after six accelerated aging cycles.When the applied load increased to 30%of the ultimate strength,the 800-hour creep strain of RHPC-LVL increased by 16.5%compared to LVL.The short-term creep strain of RHPC at 30℃ and 60℃ increased by 33%and 200%compared to LVL,respectively.By fitting the creep and recovery stages using commonly used creep models,this study provided a theoretical basis for predicting the shortterm creep of RHPC-LVL in engineering structural applications.This research could offer guidance for the development and application of RHPC-LVL.
作者
陈园
陈磊
邢志栋
王小玉
郝笑龙
CHEN Yuan;CHEN Lei;XING Zhidong;WANG Xiaoyu;HAO Xiaolong(Institute of Biomass Engineering,Key Laboratory of Energy Plants Resource and Utilization(Ministry of Agriculture and Rural Affairs),South China Agricultural University,Guangzhou 510642,Guangdong,China;Key Laboratory for Biobased Materials and Energy of Ministry of Education,College of Future Biomass,South China Agricultural University,Guangzhou 510642,Guangdong,China;College of Arts,South China Agricultural University,Guangzhou 510642,Guangdong,China)
出处
《木材科学与技术》
北大核心
2025年第6期53-61,共9页
Chinese Journal of Wood Science and Technology
基金
国家自然科学基金面上项目“超高木质纤维含量木塑复合材料动态界面流变机理”(32471786)
广东省自然科学基金青年提升项目“超高生物质纤维含量木塑复合材料创制及复合原理”(2024A1515030040)。
关键词
木塑复合材料
共挤
力学性能
蠕变
老化
wood plastic composites
coextrusion
mechanical properties
creep
aging
