The influence of irradiated recycled polypropylene compatibilizer on the impact fracture behavior of recycled polypropylene/microcrystalline cellulose composites

Abstract

The poor compatibility between a thermoplastic matrix and natural fiber reinforcement has been a limitation in the optimization of natural fiber-filled composites. Electron beam irradiation is used to modify the structure of materials. However, most researches have focused on the effect of irradiation after the fabrication of composites. Hence, this study was aimed at investigating the effect of irradiated recycled polypropylene (i-rPP) as a compatibilizer in recycled polypropylene (rPP) composites. The rPP were irradiated at different doses before the compounding process. The rPP matrices were prepared by mixing the unirradiated and irradiated rPP at ratios of 90:10 and 50:50, before they were compounded with different amounts of microcrystalline cellulose (MCC) fibers (5, 20, and 40 wt%). Radiation crosslinking, functional groups, radical formations, thermal, and impact strength characterizations were carried out. The results showed that the simultaneous incorporation of the i-rPP and MCC fibers significantly improved the impact resistance of the rPP. The synergistic combination of a higher MCC content (40 wt%) and low irradiation dose (10 kGy) at a ratio of 50:50 caused a higher degree of crosslinking and a lower radical concentration. The thermal stability was acceptable and the sub-impact fracture surface analysis revealed the effects of crack blunting. POLYM. COMPOS., 00:000-000,

Dynamic Mechanical And Water Absorption Properties Of Microcrystalline Cellulose Reinforced Polypropylene Composites: The Effect Of Unconventional Irradiation Route

“…Therefore, the present work aims to further investigate the effects of irradiated recycled PP on dynamic mechanical analysis (DMA) and water absorption properties from the developed composites. The results derived from this analysis is a supplementary research on an earlier study conducted by Lazim et al [2][3] and Samat et al [4].…”

“…The result of gel content for neat rPP and rPP/MCC composite samples has been reported in our previous work [2]. The gel content of was determined by the extraction of samples in xylene solvent at 130 O C for 24 h (ASTM D2765).…”

“…During the irradiation process, the energy is transferred from the irradiating source to the atoms of irradiated materials. This will result in a few chemical reactions taking place, such as chain scission, branching, and crosslinking [1][2] that subsequently alter the mechanical and thermal properties of the materials [2][3][4][5][6][7]. Generally, the formation of crosslinking will lead to improvements of properties.…”

“…Tensile tests were performed in both cases to evaluate the function of irradiated PPs as a compatibilizer. This unconventional irradiation route had also been further explored in our previous works [2][3][4][5] in recycled polypropylene (rPP) that was reinforced with microcrystalline cellulose (MCC). Here, the possibility of irradiated recycled PP being a compatibilizer was assessed based on the tensile, impact strength and thermal properties.…”

“…Here, the possibility of irradiated recycled PP being a compatibilizer was assessed based on the tensile, impact strength and thermal properties. In all of these cases [2][3][4][5][15][16], the properties of composites had been better than the controlled polymer, thereby proving the compatibility effect of the virgin PP or recycled PP through the use of IR.…”