Conifer Needles as Thermoplastic Composite Fillers: Structure and Properties

Abstract

This study describes the properties of thermoplastic polymer composites based on polyethylene (of low and high density) and ethylene-propylene copolymers using various types of conifer needles (pine, spruce, fir, and cedar) as fillers. For the needles, thermogravimetric analysis (TGA) and TGA/Fourier transform infrared spectroscopy (TGA/FTIR) were performed to investigate their structures and thermal resistance, as required for the composite processing methods. Moreover, structural differences were studied for the analyzed fillers and composite materials (FTIR). The results were compared with the values obtained for composites with conifer wood flour. Composites with conifer needles (pine) had increased water absorption and similar strength properties. However, irrespective of the degree of filling, composites with pine needles were positively characterized by the highest melt mass flow rate (MFR) values and showed a slightly better impact resistance than composites filled with other flours. Thus, shredded coniferous needles with sufficient thermal resistance could be successfully used as fillers in composites. This conclusion was based on thermoplastic polymers as an alternative and/or supplement to the wood flour used in the manufacture of wood-polymer composites.

Thermomechanical and Fire Properties of Polyethylene-Composite-Filled Ammonium Polyphosphate and Inorganic Fillers: An Evaluation of Their Modification Efficiency

“…One of the thermoplastic polymers' most frequently used modification methods is their application as a matrix in polymer composites. The scope of the research carried out and the introduction of powder or fibrous fillers included both the use of inorganic materials and plant-based fillers [4][5][6][7][8]. While quite a lot of attention is paid to the use of waste fillers of plant origin, at the same time, one should bear in mind the need to utilize inorganic compounds generated, among others, during production and technological processes in the metallurgical and mining industries.…”

Resistance of Conifer Needle Polyolefin Composites (CNPCs) Against Biodecomposition Caused by Fungi

“…Previously [27] we described the possibility of using various conifer needles as fillers in a polyolefin matrix. It was decided in this study to investigate the resistance of composites with conifer needles (CNPCs) to biodecomposition processes.…”