丝素纳米复合材料的热分解反应动力学及热力学

Thermal Decomposition Kinetics and Thermodynamics of Silk Fibroin Nanocomposites

对静电纺丝技术制备的丝素/聚乳酸纳米纤维复合膜进行了扫描电子显微镜观察和热重分析,利用Kissinger,Ozawa-Doyle,Vyazovkin动力学模型及Achar微分法、Coats-Redfern积分法比较了2种不同质量比(1∶5和2∶5)的丝素纳米复合膜的热分解反应动力学.结果表明,2种材料纳米纤维结构具有热力学宏观相容性,聚乳酸含量高的丝素纳米复合膜的起始分解温度、活化能和活化焓较高;丝素纳米复合膜在473~618 K的热分解过程中,SP1-5与SP2-5试样的最佳机理函数为f(α)=4(1-α)3/4与f(α)=4{(1-α)[1-(1-α)1/2]}1/2.

Scanning electron microscopy(SEM)and thermogravimetric analysis(TGA)were performed on the silk fibroin/polylactic acid nanofiber composite membranes prepared by electrostatic spinning.Thermal stability and decomposition characteristics of two silk fibroin composite membranes with different proportions(1∶5 and 2∶5) were compared by Kissinger,Ozawa-Doyle,and Vyazovkin,as well as Achar differential and Coats-Redfern integral methods.Results showed that the parameters of initial decomposition temperature,activation energy and activation enthalpy of silk fibroin nanocomposite membrane with high poly(lactic acid) content were higher.During the thermal decomposition of silk fibroin nanocomposite film at the stage of 473~618 K,the best mechanism functions of SP1-5 and SP2-5 samples are f(α)=4(1-α)3/4与f(α)=4{(1-α)[1-(1-α)1/2]^1/2.