Effect of wood fiber loading on the chemical and thermo-rheological properties of unrecycled and recycled wood-polymer composites

Pušnik Črešnar, Klementina (author), Fras Zemljič, Lidija (author), Slemenik Perše, Lidija (author), Bek, Marko (author)

Novel wood fiber (WF)-polypropylene composites were developed using the extrusion process with a twin-screw extruder. The influence of different mass addition of WF to unrecycled polypropylene (PP) and recycled PP (R-PP) on the chemical, thermal and rheological properties of the processed WF-PP and WF-R-PP composites was investigated. For this purpose, the chemical surface structure of the composites was followed with ATR-FTIR (attenuated total reflection Fourier transform infra red spectroscopy), while the thermal properties of the WF-PP composites were investigated with differential scanning calorimetry (DSC). Furthermore, the crystalline structure of the composites was determined by X-ray diffraction (XRD) analysis. Finally, the rheology of the materials was also studied. It was observed that a stronger particle formation at high additional concentrations was observed in the case of recycled PP material. The addition of WF over 20% by weight increased the crystallinity as a result of the incorporation and reorganization of the WF and also their reinforcing effect. The addition of WF to pure PP had an influence on the crystallization process, which due to the new β phase and γ phase PP formation showed an increased degree of crystallinity of the composites and led to a polymorphic structure of the composites WF-PP. From the rheological test, we can conclude that the addition of WF changed the rheological behavior of the material, as WF hindered the movement of the polymeric material. At lower concentrations, the change was less pronounced, although we observed more drastic changes in the material behavior at concentrations high enough that WF could form a 3D network (percolation point about 20%).

• Language: English
• Keywords: wood-fiber, polypropylene, thermoplastic composites, highly filled materials, sustainable and biodegradable composites, rheological properties, ATR-FTIR, DSC, XRD
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2020
• Number of pages: 17 str.
• Numbering: Vol. 10, iss. 24, art. 8863
• PID: 20.500.12556/RUL-122937
• UDC: 678.742.3:543.2
• ISSN on article: 2076-3417
• DOI: 10.3390/app10248863
• COBISS.SI-ID: 42692611
• Publication date in RUL: 17.12.2020

Record is a part of a journal

• Title: Applied sciences
• Shortened title: Appl. sci.
• Publisher: MDPI
• ISSN: 2076-3417
• COBISS.SI-ID: 522979353

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 11.12.2020

Secondary language

• Language: Slovenian
• Keywords: lesna vlakna, polipropilen, termoplastični kompoziti, polipropilensko vezivo, materiali z visokim deležem polnitve, biorazgradljivi kompoziti, reološke lastnosti