Properties Of Recycled Polypropylene Research Articles

Characteristics of the Waste Wood Biomass and Its Effect on the Properties of Wood Sanding Dust/Recycled PP Composite.

To decrease climate changes, more research focuses on decreasing waste wood biomass (WWB) burning and increasing its conversion into value-added products. The WWB was isolated from model wood processing wastewater with a new hybrid coagulant by the coagulation/flocculation method. This study is aimed to characterize the WWB and to investigate its effect in the composition of a hybrid lignocellulosic filler on the properties of recycled polypropylene (rPP)-based wood–plastic composites (WPCs). The waste biomass contained high-molecular lignin and hemicelluloses substances and represented a finely dispersed powder. It was hydrophobic and was characterized by enhanced thermal stability. To minimize the negative effect of polymer wastes on the environment, recycled polypropylene as a polymer matrix was used with the hybrid filler in fabricating WPC samples. The presence of the coagulated WWB in the hybrid filler composition positively affects the mechanical properties, water uptake and dimensional stability of the composite samples. Such a behavior of the waste biomass showed its function as a compatibilizer, which promoted the interfacial adhesion in the composite system.

Mechanical Properties Improvement of Recycled Polypropylene with Material Value Conservation Schemes Using Virgin Plastic Blends

Plastic packaging that applied material value conservation paradigm will generate good quality plastic waste. It can be recycled to produce raw material for new packaging. However, repetitive recycling has impacts on lowering its mechanical properties. Recycled plastic is expected not to undergo mechanical properties degradation. This research proposed to blend recycled plastic pellets with its virgin plastic to reduce mechanical properties degradation. Mechanical properties of recycled polypropylene are compared to 100% virgin polypropylene and recycled/virgin polypropylene blends with composition 90/10, 70/30, 50/50, 30/70, and 10/90. Mechanical properties tested in this research are modulus of elasticity, tensile strength, elongation at break, and density. All were tested according to ASTM for mechanical properties testing materials. This study revealed blending 50% virgin polypropylene significantly improves mechanical properties of recycled plastics and keep improving at 70% virgin polypropylene. The optimum improvement based on four mechanical properties was found at composition 30/70 of recycled/virgin plastic. Elongation at break is the most critical property where degradation was found at 90/10. Blending 6th recycled and virgin polypropylene gives opportunities to improve the mechanical properties of recycled plastic products with careful consideration of the compositions. By implementing material value conservation, good quality plastic waste can be recycled repetitively. This will decrease accumulation of plastic waste generation and usage of non-renewable plastic’s raw material. The positive impact is not only to economic of plastic industry but also to the quality of environment.

Mechanical properties and failure modes of recycled polypropylene/microcrystalline cellulose composites

Abstract The effects of microcrystalline cellulose (MCC) fibre on the properties of recycled polypropylene (rPP) composites were investigated. A coupling agent, maleic anhydride grafted-polypropylene (MAPP) was used to improve the interfacial adhesion between the MCC fibres and rPP matrix. A series of rPP/MCC composites, with or without MAPP, were compounded with an extruder and then moulded with an injection moulding machine. It was found that without MAPP, an increase in MCC loadings caused degradation in the tensile strength of rPP composites. However, the impact strength was higher compared to that of neat rPP prior to its decrease caused by the increase in MCC loading. All mechanical properties showed improvement after MAPP was added, especially in tensile modulus. FESEM morphology also revealed better interfacial adhesion between the MCC fibres and the rPP matrix. Fracture analysis indicated that the ductile and quasi-brittle behaviours in both types of rPP/MCC composites (with or without MAPP) were affected by the concentration of fibres and the interfacial adhesion strength.

The Effect of Silane Treated Sugar Cane Bagasse on Mechanical, Thermal and Crystallization Studies of Recycled Polypropylene

This article describes the results of an investigation on the influence of loading silane treated sugar cane bagasse (SB) on the morphology and properties of recycled polypropylene (rPP). The samples are prepared through melt extrusion followed by injection moulding. The Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) results show that SB-rPP composites have a fairly strong interfacial interaction and a change in crystallization for the highest containing SB composite, however, some fibre pull-outs are observed as the SB content is increased. The interaction influences the thermal and mechanical properties of the samples in a complex way. There are strong indications of a stronger interfacial interaction on the highest containing SB composite, which is supposedly accountable for the increased crystallinity and melting temperature.

Effect of Graphene Loading on Mechanical and Morphological Properties of Recycled Polypropylene/Polyaniline Nanocomposites

The investigation of the graphene (GN) performance in improving mechanical properties of recycled polypropylene with crosslinkedpolyaniline (rPP-g-PANI) was prepared via ultrasound extrusion. The concentration of GN in the research was varied from 0.5 to 3 phr, while polyaniline (PANI) and dycumil peroxide(DCP) were fixed at 4 wt. % and 1 phr loading, respectively. The morphological structure of the nanocomposites was investigated using fill emission scanning electron microscopy (FESEM) and confirmed a good dispersion of PANI and GN on rPP matrix. The increasing loading of GN has promoted a slight improvement in tensile modulus and tensile strength at 1.5 and 2 phr of GN loadings, respectively. However elongation at break showed a decrease at all PANI loadings due to lack of interfacial addition between PANI/GN particles and the rPP matrix.

Processing and properties of recycled polypropylene modified with elastomers

This work presents a study of the processability and the characterisation of blends of recycled polypropylene (PP) with two different elastomers. The aim of the work was to demonstrate that the introduction of an elastomeric phase could improve the properties of recycled PP without changing the processing characteristics of the blends in terms of viscosity and temperature. The study was carried out using thermal analysis, thermomechanical analysis and rheological measurements. The rheological analysis of blends of recycled PP and elastomeric additives showed that, despite the different rheological behaviour of the added elastomers, the properties of the blends were dominated by the thermoplastic (PP) phase. A thermogravimetric analysis of the selected blends allowed the calculation of the parameters related to the thermal degradation of such materials and the main results indicated that there were no significant differences between virgin and recycled PP in terms of behaviour at high temperatures. Furthermore, the blending of recycled PP with elastomers did not result in a significant change in thermal degradation behaviour. Crystallisation studies showed that blending polypropylene with elastomers influenced the rate and amount of crystallisation, which increased at low additive concentrations and then decreased at a higher elastomer content. Thermomechanical analysis showed the immiscible character of the blends. The mechanical properties of the blends were affected by the concentration of elastomer, which also influenced the crystallinity of the material.