聚乙二醇/纤维素相变材料的制备及性能表征

以微晶纤维素（MCC）为原料，制备纤维素海绵（Cell），并以其作为基体，通过物理共混的方法与聚乙二醇（PEG）PEG-6000进行复合，制备聚乙二醇/纤维素相变材料（PCMs），研究了PCMs的结构与相变储能性能。实验结果表明：PCMs中PEG的质量分数可以达到90.77%，且相变过程中不会发生液体泄漏的问题。FT-IR分析表明纤维素基体和PEG之间存在明显的氢键作用，无新化合物产生。XRD分析结果表明：与纯PEG-6000相比，纤维素基体的加入不会改变PEG的结晶形态，但会降低PEG的结晶度。DSC结果表明，PCMs的熔融焓（ΔH_f）随着PCMs中PEG质量分数的增加而增大，ΔH_f最高可达146.88J/g（PCM₅），但均小于纯的PEG（179.09J/g）；PCMs的结晶焓（ΔH_c）随着PCMs中PEG质量分数的增加而降低，ΔH_c的绝对值最高可达137.81J/g。TG分析表明，当环境温度小于250℃时，PCMs的热稳定性较好。

Preparation and Characterization of Polyethylene Glycol/Cellulose Phase Change Materials

The cellulose sponges(Cell) was prepared with the microcrystalline cellulose(MCC) as raw material. Based on the homemade cellulose sponges, polyethylene glycol/cellulose phase change materials(PCMs) were prepared by physical blending method with polyethylene glycol(PEG) PEG-6000 as phase change material. The structure and phase transition properties of PCMs were studied. Experimental results showed that the mass fraction of PEG in PCMs could reach 90.77% without liquid leakage during phase change process. FT-IR results showed that there was obvious hydrogen bonding in cellulose sponges between cellulose substrates and PEG-6000 and there was no new compound. XRD analysis results showed that, compared with pure PEG-6000, the addition of cellulose substrates didn't change the crystalline form of PEG, but decreased the crystallinity of PEG in PCMs. DSC analysis results showed that the melting enthalpy(ΔH_f) of PCMs increased with the increase of PEG mass fraction, the value of which could reach 146.88J/g(PCM₅), and was less than that of pure PEG(179.09J/g). But the crystallization enthalpy(ΔH_c) of PCMs reduced with the increase of PEG mass fraction, the absolute value of which could reach 137.81J/g. At last, TG analysis showed that the prepared PCMs had good thermal stability below 250℃.