王梦颖 张国庆 张顺花

摘 要：为探究相变蜡（PC-WAX）/聚乙烯醇（PVA）/水（H2O）三元共混物的相容性和流变性，通过溶液共混法制得不同含量的PC-WAX/PVA/H2O三元共混物，采用控制应力型旋转流变仪研究该三元共混物的流变性能。结果表明：PC-WAX/PVA/H2O三组分在一定配比下高温高速搅拌后具有很好的相容性，得到的三元共混物呈乳白色黏稠状，经动态流变测试发现其内部具有网络结构，特征表现类似固体。稳态流变测试下均匀共混的试样呈现非牛顿流体的性质，增大PC-WAX含量会使该三元共混物的剪切黏度增大，低剪切速率范围的剪切变稀行为明显。当剪切速率为1.00～8.96 s-1，三元共混物中PC-WAX添加量由0增加到4.5时，其非牛顿指数由0.87降至0.38，结构黏度指数由5.5上升至26.4，非牛顿性增强，结构化程度增大。升高温度会降低三元共混物的剪切黏度和黏流活化能;随剪切速率的增大，剪切黏度对温度的敏感性下降。

关键词：相变蜡;聚乙烯醇;三元共混;相容性;流变性能

中图分类号：TS195.644  文献标志码：A

文章编号：1009-265X（2021）03-0078-06

Abstract： In order to explore the rheology and compatibility of phase change wax （PC-WAX）/polyvinyl alcohol （PVA）/water （H2O） ternary blends， ternary blends of PC-WAX/PVA/H2O with different content were prepared by solution blending， and the rheological properties were studied by a controlled stress rotary rheometer. The experimental results showed that the ternary blend had good compatibility after high temperature and high speed stirring at a certain ratio and the ternary blend was milky white and viscous. The dynamic rheological test found that it had a network structure inside， and its characteristics were solid-like. The homogeneously blending samples under the steady state rheology test showed a property of non-Newtonian fluids. The shear viscosity of the ternary blend rose when the PC-WAX content increased. Shear thinning behavior in the low shear rate range was evident. The non-Newtonian properties and the degree of structure were enhanced when the shear rate was 1.00—8.96 s-1， the amount of PC-WAX in the ternary blend increased from 0 to 4.5， the non-Newtonian index decreased from 0.87 to 0.38， and the structural viscosity index increased from 5.5 to 26.4. The shear viscosity and the activation energy of viscosity flow of ternary blends decreased by increasing the temperature. With the increase of shear rate， the sensitivity of shear viscosity to the temperature declined.

Key words： phase change wax; polyvinyl alcohol; ternary blends; compatibility; rheological property

相變材料是一种在指定温度或温度范围内，通过改变自身状态吸收和释放大量潜热的功能性材料[1]。优良的相变材料应具备相变潜热高、温度适宜、性能稳定、可反复使用等性质。石蜡作为价格低廉易获得的有机类相变材料，不易发生相分离及过冷现象，且无腐蚀性，常用于与其他材料制备复合相变蓄热材料[2-4]。石蜡主要由直链烷烃混合而成，随链长的增长，烷烃溶解热和熔点均增大[5]，不同组成的石蜡可应用于相变墙体、储能地板、天棚或太阳能储能中[6]。……