Poly(lactic acid) (PLA) derived from renewable resources is an alternative to petroleum-based polymers. In this work, natural fiber filled PLA-halloysite nanotube (HNT) composites were prepared using melt blending followed by compression molding. Maleic anhydride grafted onto PLA (MA-g-PLA) was used to improve the interfacial bonding quality between hydrophobic and hydrophilic phases in the natural fiber filled PLA-HNT composites. The performance properties of the natural fiber filled PLA-HNT composites were characterized by tensile, flexural and impact tests, thermogravimetric analysis, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). DSC results showed that the loading of HNT could promote cold crystallization, and the improvement of crystallinity of the PLA-HNT composites was by 16% with the addition of MA-g-PLA.The flexural and impact strengths of PLA-HNT composites were not affected adversely up to 10 phr of HNT loading, but tensile strength of PLA-HNT composites decreased gradually. In addition, numerous agglomerates of the nanotubes for PLA-HNT composites with 15 phr loading of HNT were detected with SEM micrographs. However, moduli of elasticity of PLA-HNT composites enhanced by 40% with increment of HNT loading in polymer matrix. Based on the findings, HNT could be used as nanofiller up to 10 phr in PLA matrix.
Bu çalışmada, atık lignoselülozik maddelerle üretilen odun plastik kompozitlerin termal özellikleri ve yangına karşı dirençleri araştırılmıştır. Bu amaç için lignoselülozik atıklar, yüksek yoğunluklu polietilen (YYPE), sodyum borat (boraks) ve borik asit kullanılmıştır. Kompozit malzemesinin üretimi aşamasında çift vida ekstruder kullanılmıştır. Elde edilen granül malzeme 175 °C'de preste preslenerek levha haline getirilmiştir. Yapılan testlertde farklı oranlarda odun plastik kompozitlere eklenen borik asit ve boraks maddelerinin termal gravimetrik analiz (TGA), yatay yanma ve limit oksijen indeks (LOI) sonuçları üzerine etkileri araştırılmıştır. Elde edilen sonuçlara göre borlu bileşiklerin miktarı arttıkça kompozit malzemede bulunan lignoselüloziklerin ve plastik malzemenin yanma derecelerinin (°C) yükseldiği anlaşılmıştır. Ayrıca kompozitlere eklenen borlu madde miktarı arttıkça yatay yanma hızının düştüğü anlaşılmıştır.
The aim of this paper was to investigate the effects of wood flour on the mechanical, morphological and thermal properties of poly (L-lactic acid) (PLA)-chitosan biopolymer composites produced by compression molding. The composites were characterized by a combination of mechanical properties, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The addition of chitosan to PLA matrix reduced the tensile strength from 57,1 MPa for pure PLA to 34,3 MPa for 5% chitosan and 11,5 MPa for 10% chitosan, and the flexure strength from 72,3 MPa for pure PLLA to 30,4 MPa for 5% chitosan and 24,6 MPa for 10% chitosan. The change trend in the young's modulus was found to be similar as compare with the tensile strength. However, the flexure modulus generally increased with the addition of the chitosan as comparison with pure PLA. The mechanical properties of the PLA-chitosan blends with wood flour were found to be lower than theirs of the pure PLA. According to SEM images, some holes and small voids at various diameters on the fractured section of the all composites were seen. T onset , T 10% , T 50% , T 85% of the pure PLA decreased with the addition of both chitosan and wood flour. Thermal stability of the PLA-chitosan blends was determined to be better than the PLA-chitosan composites with wood flour.
The aim of the paper was to determine the mechanical, thermal, and morphological properties of heat-treated wood-polypropylene polymer composites (WPCs) and to select the composites having the optimum properties with the PROMETHEE method. In this study, polypropylene (PP) as a matrix, wood thermally treated at 180°C and 220°C as reinforcement filler were examined for preparing composites. The PP composites were compounded using a twin-screw extruder and test specimens were prepared by compression moulding. According to the test results, the thermal and mechanical properties of the WPCs generally increased with the addition of heat-treated wood fillers. The SEM images showed that the wood fillers dispersed better in the PP matrix as the particle size decreased from 40 mesh to 100 mesh. The WPCs having the optimum mechanical and thermal properties were determined for 40 mesh heat-treated wood at 220°C and 20 wt-% loadings with PROMETHEE method.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.