含脲醛树脂胶黏剂的杨木刨花板的热解特性

Pyrolysis characteristics of poplar particleboards containing UF resins

为探明胶黏剂对废弃刨花板热解的影响,采用热重分析技术,以20℃/min的恒定升温速率对杨木、杨木刨花板和脲醛树脂的热解特性进行了分析。结果表明:3种材料的热解基本都可分为干燥失水、快速热解和缓慢分解3个阶段。采用一级反应动力学模型对快速热解阶段进行计算,得出杨木的活化能为70.21kJ/mol,杨木刨花板的活化能为46.45kJ/mol,脲醛树脂的活化能为54.86kJ/mol。杨木刨花板和杨木具有相似的热解规律,但其最大热解速率(14.1%/min)明显低于杨木(22.1%/min)和脲醛树脂(21.7%/min),且快速热解阶段存在滞后现象,推测杨木刨花板中的脲醛树脂提高了其热稳定性,尤其在第二阶段对杨木刨花板热解过程产生了一定的抑制作用。

TG and DTG analysis was used to evaluate the influence of UF resins during the pyrolysis of waste particleboards in this paper.Poplar wood,particleboard and UF resin were studied with the heating rate of 20 ℃/min.Results showed that the process of three samples could be mainly divided into three stages：dehydration,fast pyrolysis and slow degradation.By assuming fist order reaction model,the activation energy of wood was 70.21 kJ/mol,particleboard was 46.45 kJ/mol and UF resin was 54.86 kJ/mol.Similar pyrolysis characteristics were found in wood and particleboard.However,the degradation rate of particleboard（14.1%/min） was much lower than that of wood（22.1%/min） and UF resin（21.7%/min）.Compared with wood,there was a lateral shift to higher temperature in DTG curves for particleboard.It can be concluded that the thermal stability of particleboard is enhanced by UF resin and the degradation is inhibited by UF resin,especially during the second stage.