Martins Carla I, Gil Vitória, Rocha Sara
Institute for Polymers and Composites, University of Minho, Campus de Azurém, 4800-058 Guimaraes, Portugal.
Polymers (Basel). 2022 Jan 4;14(1):193. doi: 10.3390/polym14010193.
This research addresses the importance of pine wood sawdust granulometry on the processing of medium-density polyethylene (MDPE)/wood composites by rotational molding and its effects on the morphological, mechanical and aesthetical properties of parts, aiming to contribute for the development of sustainable wood polymer composites (WPC) for rotational molding applications. Pine wood sawdust was sieved (<150, 150, 300, 500, 710, >1000 µm) and analyzed for its physical, morphological and thermal characteristics. Rotational molded parts were produced with matrix/wood ratios from 90/10 to 70/30 wt% considering different wood granulometries. As a natural material, wood changed its color during processing. Granulometries below 500 µm presented better sintering, homogeneity and less part defects. Furthermore, 300-500 µm favored the impact resistance (1316 N), as irregular brick-shaped wood was able to anchor to PE despite the weak interfacial adhesion observed. The increase of wood content from 10 to 30% reduced the impact properties by 40%, as a result of a highly porous structure formed, revealing sintering difficulties during processing. WPC parts of differentiated aesthetics and functionalities were achieved by rotational molding. A clear relationship between wood granulometry and WPC processing, structure and properties was identified.
本研究探讨了松木锯末粒度对通过滚塑加工中密度聚乙烯（MDPE）/木材复合材料的重要性及其对部件的形态、机械和美学性能的影响，旨在为开发用于滚塑应用的可持续木材聚合物复合材料（WPC）做出贡献。对松木锯末进行筛分（<150、150、300、500、710、>1000 µm），并分析其物理、形态和热特性。考虑到不同的木材粒度，以90/10至70/30 wt%的基体/木材比例生产滚塑部件。作为天然材料，木材在加工过程中颜色发生了变化。粒度低于500 µm的锯末表现出更好的烧结性、均匀性和更少的部件缺陷。此外，300 - 500 µm的粒度有利于提高抗冲击性（1316 N），因为尽管观察到界面粘附较弱，但不规则砖形木材仍能与PE锚固。木材含量从10%增加到30%会使冲击性能降低40%，这是由于形成了高度多孔的结构，表明加工过程中存在烧结困难。通过滚塑实现了具有不同美学和功能的WPC部件。确定了木材粒度与WPC加工、结构和性能之间的明确关系。
