PHB基CA-MA二元低共熔脂肪酸定形相变材料的制备

Preparation of PHB-based CA-MA Binary Eutectic Fatty Acid Phase Change Materials

以聚-β-羟丁酸酯(PHB)作为基体材料,癸酸-肉豆蔻酸(CA-MA)二元低共熔脂肪酸作为相变剂,利用浇注法制备了含有不同比例脂肪酸的室温相变材料。通过热循环试验、傅里叶红外光谱(FTIR)、差示扫描量热(DSC)、扫描电镜(SEM)、热重分析(TG)和动态机械分析(DMA)等方法研究了材料的综合性能。结果表明,滤纸扩散法得出PHB对CA-MA二元低共熔脂肪酸的最大包覆量为40%,此时材料的相变温度为24.65℃,相变焓值为140.26 J/g,复合材料具有很好的相变性能。添加适量的羧甲基纤维素钠(CMC)后,材料的相变温度为24.58℃,相变焓为139.74 J/g,且CMC的加入使CA-MA的热稳定性有所提高,热分解温度提高了19℃左右,同时储能模量(E')提高了5 GPa,材料的刚性提高且微观形貌分散性良好;材料经历热循环前后相变温度、相变焓值和最初热分解温度变化很小。

In this paper,poly-β-hydroxybutyrate(PHB)was used as the matrix material and CA-MA binary eutectic fatty acid was screened as the phase change agent.The room temperature phase change materials containing different proportions of fatty acids were prepared by pouring method.The comprehensive properties of the composites were studied by thermal cycling test,Fourier transform infrared spectroscopy(FTIR),differential scanning calorimetry(DSC),scanning electron microscopy(SEM),thermogravimetric analysis(TG)and dynamic mechanical analysis(DMA).The maximum coating amount of PHB on CA-MA binary eutectic fatty acids was 40%by filter paper diffusion method.At this time,the phase transition temperature of the material was 24.65℃,the phase change enthalpy was 140.26 J/g,the composite had a good phase transition performance.After adding the appropriate CMC,the phase transition temperature of the material was 24.58℃,the enthalpy of transformation was 139.74 J/g,the thermal stability of CA-MA of the materion was increased by 19℃,and the storage modulus(E′)was increased by 5 GPa,the rigidity of the material was improved and the microstructure of the dispersion was good.The change of phase transition temperature,phase change enthalpy and initial thermal decomposition temperature before and after thermal cycling were very small.