高级检索
    臧小榕, 母军, 张新宇, 赖宗元, 储德淼. 国产栓皮栎软木热响应特性研究[J]. 北京林业大学学报, 2018, 40(9): 127-133. DOI: 10.13332/j.1000-1522.20180212
    引用本文: 臧小榕, 母军, 张新宇, 赖宗元, 储德淼. 国产栓皮栎软木热响应特性研究[J]. 北京林业大学学报, 2018, 40(9): 127-133. DOI: 10.13332/j.1000-1522.20180212
    Zang Xiaorong, Mu Jun, Zhang Xinyu, Lai Zongyuan, Chu Demiao. Research on thermal response characteristics of domestic Quercus variabilis cork[J]. Journal of Beijing Forestry University, 2018, 40(9): 127-133. DOI: 10.13332/j.1000-1522.20180212
    Citation: Zang Xiaorong, Mu Jun, Zhang Xinyu, Lai Zongyuan, Chu Demiao. Research on thermal response characteristics of domestic Quercus variabilis cork[J]. Journal of Beijing Forestry University, 2018, 40(9): 127-133. DOI: 10.13332/j.1000-1522.20180212

    国产栓皮栎软木热响应特性研究

    Research on thermal response characteristics of domestic Quercus variabilis cork

    • 摘要:
      目的软木是一种具有黏弹性的天然高分子材料,除天然软木塞以外,软木制品多由软木颗粒施胶后热压而成,软木材料主要化学组分的熔融温度、玻璃化转变温度等热转变温度对了解软木的黏弹性和制定热加工工艺具有重要的理论参考价值。
      方法首先对栓皮栎软木进行热重分析以了解其热稳定性,确定软木发生热降解的最低温度,之后又采用了DSC、DMA、TMA这3种热分析方法对国产栓皮栎软木材料在热解起始温度内的热效应温度进行分析,并相互验证。
      结果热重分析结果显示在219℃之前栓皮栎软木基本不发生热降解,采用DSC、DMA、TMA方法测得的软木脂微晶的熔融温度分别为66℃、78℃(1Hz)和78℃,通过DMA测得软木脂无定形区在频率为1Hz时的玻璃化转变温度在0.7℃左右,在-66℃附近有一次级松弛转变,各热效应温度与栓皮槠软木略有差异,应与两者化学组分的单体构成和分子间作用力之间的差异相关。此外,由于软木径向壁上具有褶皱,采用TMA测试时可发现在加热条件下软木径向尺寸受热膨胀程度要大于轴向。
      结论在栓皮栎软木发生热解前的温度范围内存在主要成分软木脂的各热效应转变温度,据此确定合适的软木热加工温度,可通过增加软木的黏性流动来促进软木材料的热成型。

       

      Abstract:
      ObjectiveCork is a kind of natural polymer material with viscoelasticity. Cork products are mostly formed by hot pressing of cork particles after sizing except natural cork stoppers. The melting temperature, glass transition temperature and other thermal transition temperatures of the main chemical components of cork materials have important theoretical reference value for understanding the viscoelasticity of cork and formulating thermal processing technology.
      MethodFirstly, the thermogravimetric analysis of the Quercus variabilis cork was carried out to determine the pyrolysis initiation temperature. Then, three thermal analysis methods, DSC, DMA and TMA, were used to analyze the thermal effect temperature of the domestic Quercus variabilis cork material within the pyrolysis initiation temperature and verify each other.
      ResultThermogravimetric analysis showed that the Quercus variabilis cork did not undergo thermal degradation before 219℃. The melting temperatures of suberin's microcrystalline phases measured by DSC, DMA and TMA were 66℃, 78℃ (1Hz) and 78℃, respectively. The glass transition temperature of the amorphous region of suberin measured by DMA was about 0.7℃, and there was a secondary relaxation transition near -66℃. Each thermal effect temperature was slightly different from that of Quercus suber cork, which was related to the difference in monomer composition and intermolecular force of the chemical components of the two species cork. In addition, due to the corrugations on the radial wall of the cork cell, it was found that the thermal expansion of the cork radial dimension was greater than that of the axial direction under the heating condition.
      ConclusionIn the temperature range before the pyrolysis of Quercus variabilis cork, suberin, the main component of the cork, will undergo different thermal effects, according to which the appropriate cork hot processing temperature can be determined, and the thermoforming of the cork material can be promoted by increasing the viscous flow of the cork.

       

    /

    返回文章
    返回