ABSTRACT

The use of polymeric materials for the sustainable packaging sector is constantly improving due to meet the required properties for the application. However, most polymers come from non-renewable sources and can harm the environment, if inappropriately disposed. Therefore, this study aims to develop environmentally friendly composites based on polycaprolactone (PCL), a biodegradable polymer, reinforced with different contents (0, 5, and 15 wt%) of wood flour (WF), a residue of the timber industry. The samples were processed using a co-rotational twin screw extruder, followed by hot pressing. Water absorption test, contact angle, thermal aging test, Izod impact resistance, tensile tests, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) were performed. By the results, it was possible to verify that the presence of WF contributed to the degradation by hydrolysis due to its hydrophilic character. As the WF content increased, mainly for the PCL/15 wt% WF composite, the material became rigid due to a 61% increase in the Young’s modulus in relation to the neat PCL. The composite’s morphology characteristics showed good interfacial adhesion of the WF with the PCL matrix. The PCL/5 wt% WF composite showed very satisfactory results in terms of mechanical and thermal properties, in addition to a good interaction with the PCL matrix.

摘要

由于满足应用所需的性能，可持续包装领域对聚合物材料的使用正在不断改进。然而，大多数聚合物来自不可再生资源，如果处置不当，会危害环境。因此，本研究旨在开发基于聚己内酯 (PCL) 的环保复合材料，这是一种可生物降解的聚合物，用不同含量（0、5 和 15 wt%）的木粉 (WF) 增强，木粉是木材工业的残留物。使用同向双螺杆挤出机加工样品，然后进行热压。进行了吸水率测试、接触角、热老化测试、悬臂梁式抗冲击、拉伸测试、扫描电子显微镜（SEM）和差示扫描量热法（DSC）。根据结果​​，可以证实 WF 的存在由于其亲水特性而导致水解降解。随着 WF 含量的增加，主要是对于 PCL/15 wt% WF 复合材料，由于杨氏模量相对于纯 PCL 增加了 61%，因此材料变得坚硬。复合材料的形态特征表明 WF 与 PCL 基体具有良好的界面粘附性。PCL/5 wt% WF 复合材料在机械和热性能方面表现出非常令人满意的结果，此外还与 PCL 基体具有良好的相互作用。复合材料的形态特征表明 WF 与 PCL 基体具有良好的界面粘附性。PCL/5 wt% WF 复合材料在机械和热性能方面表现出非常令人满意的结果，此外还与 PCL 基体具有良好的相互作用。复合材料的形态特征表明 WF 与 PCL 基体具有良好的界面粘附性。PCL/5 wt% WF 复合材料在机械和热性能方面表现出非常令人满意的结果，此外还与 PCL 基体具有良好的相互作用。