Wang Yingnan, Mertiny Pierre
Department of Mechanical Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
Polymers (Basel). 2024 Aug 24;16(17):2403. doi: 10.3390/polym16172403.
Thermoset-based polymer composites containing functional fillers are promising materials for a variety of applications, such as in the aerospace and medical fields. However, the resin viscosity is often unsuitably high and thus impedes a successful filler dispersion in the matrix. This challenge can be overcome by incorporating suitable low-viscosity modifiers into the prepolymer. While modifiers can aptly influence the prepolymer rheology, they can also affect the prepolymer curing behavior and the mechanical and thermal properties of the resulting matrix material. Therefore, this study investigates the effects that a commercial-grade low-viscosity additive (butyl glycidyl ether) has on a common epoxy polymer system (diglycidyl ether of bisphenol-A epoxy with a methylene dianiline curative). The weight percentage of the modifier inside the epoxy was varied from 0 to 20%. The rheological properties and cure kinetics of the resulting materials were investigated. The prepolymer viscosity decreased by 97% with 20 wt% modifier content at room temperature. Upon curing, 20 wt% modifier addition reduced the exothermic peak temperature by 12% and prolonged the time to reach the peak by 60%. For cured material samples, physical and thermo-mechanical properties were characterized. A moderate reduction in glass transition temperature and an increase in elastic modulus was observed with 20 wt% modifier content (in the order of 10%). Based on these findings, the selected material system is seen as an expedient base for material design due to the ease of processing and material availability. The present study thus provides guidance to researchers developing polymer composites requiring reduced prepolymer viscosity for successful functional filler addition.
含有功能性填料的热固性聚合物复合材料是适用于多种应用的有前景的材料，例如在航空航天和医疗领域。然而，树脂粘度往往过高，从而阻碍了填料在基体中成功分散。通过在预聚物中加入合适的低粘度改性剂可以克服这一挑战。虽然改性剂可以恰当地影响预聚物的流变学，但它们也会影响预聚物的固化行为以及所得基体材料的机械和热性能。因此，本研究考察了一种商业级低粘度添加剂（丁基缩水甘油醚）对一种常见环氧聚合物体系（双酚A环氧树脂与亚甲基二苯胺固化剂）的影响。环氧中改性剂的重量百分比在0%至20%之间变化。研究了所得材料的流变性能和固化动力学。在室温下，当改性剂含量为20 wt%时，预聚物粘度降低了97%。固化时，添加20 wt%的改性剂使放热峰值温度降低了12%，并使达到峰值的时间延长了60%。对于固化材料样品，对其物理和热机械性能进行了表征。当改性剂含量为20 wt%时（约为10%），观察到玻璃化转变温度适度降低，弹性模量增加。基于这些发现，由于易于加工和材料可得性，所选材料体系被视为材料设计的便利基础。因此，本研究为开发需要降低预聚物粘度以成功添加功能性填料的聚合物复合材料的研究人员提供了指导。
