【摘要】 采用步冷曲线法和差示扫描量热法考察不同分子量聚乙二醇(PEG)及其二元相变体系的相变特性。结果表明,PEG分子质量和组分质量比对相变体系的相变温度和相变潜热有较大的影响,随着PEG分子量的增大,相变起始温度和相变峰温均呈升高趋势,相变潜热先升后降;二元相变体系PEG2000/PEG4000不同质量比步冷曲线均有明显的温度平台,结晶温度38.4~43.2℃,且变化趋势相近;DSC分析PEG2000/PEG4000相变温度和相变潜热均处于PEG2000和PEG4000单一组分范围之间,不同质量比时升温过程中双组分单独作用出现双峰,降温过程中双组分协同作用出现单峰。因此,将不同分子量PEG按一定质量比例共混可实现温度调控的相变材料。更多还原

【Abstract】 Step cooling curves and differential scanning calorimetry( DSC) was used to test and analyse the different molecular weight PEG and two components PEG system,in order to measure their phase change characteristics. The result showed that molecular weight and proportion of PEG had effect on phase change energy and temperature change,and the PEG2000/PEG4000 system was more suitable as an energy storage material for temperature auto-control,the crystallization temperature were 38. 4 ~ 43. 2 ℃; also the molecular weight of PEG had effect on two components PEG system,there was bimodal phenomenon in the heating direction; phase change behavior was accurately changed by adjusting proportion of two components system to obtain the expected energy storage material.更多还原