填缝型微波膨化木基金属复合材料制备及其性能表征

Preparation and property characterization of crack-filled type microwave puffed wood based metal composites

【目的】以高能微波处理后的木材增值利用为研究目标,制备填缝型微波膨化木基金属复合材料(WMC),为微波处理人工林实木增值利用提供参考。【方法】采用抽真空浸渍方法,以锡铋低熔点合金和辐射松微波膨化木为原料,制备填缝型WMC,通过扫描电镜、能谱分析、计算机层析成像、动态热机械分析、热重分析、差示扫描量热分析、X射线衍射分析、红外光谱等测试技术,表征和分析WMC的微观形貌、热稳定性、表面接触角等性能。【结果】锡铋合金填充在微波膨化木的缝隙处,与木材形成“机械互锁”方式的啮合结构,使其在缝隙处紧密结合,提高了界面结合强度。WMC中锡和铋的质量分数分别为25.97%和31.13%,计算机层析扫描图像重构了锡铋合金在WMC中的空间分布位置,实现了WMC可视化的三维渲染,展示了其独特的纹理。WMC与基材相比具有更高的贮存模量、损耗模量和残炭量,热稳定性得到提高。WMC未出现新的酯类、醚类等官能团特征峰,晶体结构未受到破坏,结晶度呈现上升趋势,由基材的25.9%增加至38.6%。60 s时接触角比基材提高了172%,疏水性显著提高。【结论】本研究制备了填缝型微波膨化木基金属复合材料,观察与模拟了锡铋合金在微波膨化木中的分布,表征了其热稳定性与表面接触角等性能,为基于高能微波处理木材研制新型木质产品提供了新思路。

[Objective]To achieve the value-added utilization of wood after high energy density microwave treatment,crack-filled type microwave puffed wood based metal composites(WMC)was prepared,which provided a reference for the efficient utilization of planted solid wood treated by microwave.[Method]Tinbismuth low melting point alloy(LMA)was used to impregnate microwave puffed Pinus radiata wood to prepare WMC by vacuum impregnation method.The micro-morphology,thermal stability,surface contact angle and other properties of WMC were characterized and analyzed by SEM,EDS,CT,DMA,TG,DSC,XRD,FTIR,etc.Meanwhile,the compound mechanism of LMA and microwave puffed wood was discussed.[Result]LMA was filled in the cracks of the microwave puffed wood and formed a mechanical interlocking meshing structure with wood,making it tightly combined at the cracks and improving the interface bonding strength.The mass percentages of Sn and Bi in WMC were 25.97%and 31.13%,respectively.The CT scan image reconstructed the spatial distribution of LMA in WMC,realized three-dimensional rendering of WMC visualization,and showed its unique texture.Compared with the untreated wood sample,WMC had higher storage modulus,loss modulus and char yield,and the thermal stability was improved.In addition,there were no new functional group characteristic peaks such as esters and ethers in WMC.The crystal structure of WMC was not destroyed,and the crystallinity of WMC showed an upward trend,increasing from 25.9%of the untreated wood sample to 38.6%.The surface contact angle was 172%higher than that of the untreated wood sample at 60 s,and the hydrophobicity was significantly improved.[Conclusion]In this study,a crack-filled microwave puffed wood based metal composites was prepared,the distribution of tin-bismuth alloy in microwave puffed wood was observed and modeled,and thermal stability and surface contact angle were characterized,which provided a new idea for the development of new wood products based on high energy density microwave treatment of wood.