Jyoti Agarwal

Polypropylene (PP)/sisal fibre (SF)/carbon fibre (CF) hybrid composites were prepared by melt blending process at a variable weight percentage (wt%) of carbon: sisal fibre loading (20:10, 15:15, 10:20, and 5:25). MA-g-PP (MgP) as a compatibiliser was used to improve the dispersion of the fibres within the PP matrix. The composites were subjected to mechanical tests to optimize the fibre content of CF: SF. Incorporation of 20 wt% of CF and 10 wt% of SF with 5 wt% MgP resulted in higher mechanical performance of about 67.02 and 112% over that of PP/SF composite. Similarly, the impact strength was found to be optimum which enhanced to the tune of 39.62% as compared with PP/SF composites. Halpin Tsai model was used to compare the theoretical tensile modulus of PP/SF/MgP composites and PP/SF/CF/MgP hybrid composites with experimental evaluated values. Fracture toughness parameters such as K _IC (critical stress intensity factor) and G _IC (critical strain energy release rate) are determined for PP/SF/MgP composites and PP/SF/CF/MgP hybrid composites and compared by using single edge notch test. DSC study showed higher melting temperature (T _m ) of PP/SF/CF/MgP composites as compared to PP revealing the enhancement in thermal stability. TGA/DTG study revealed the synergistic effect of the hybrid composite thus confirming the hybridisation effect of the system. DMA study showed that the hybridisation of CF and SF within the matrix polymer contributes to an increase in the storage modulus (Eʹ). Morphological observation by SEM confirmed that the carbon fibres and sisal fibres are well uniformly dispersed within the PP matrix, in the presence of MgP.

The present study focuses on the isolation and characterization of the cellulose nanocrystals (CNCs) from the pineapple peel waste (PPW) (agro‐waste) and sisal fiber (SiF) (natural fiber) employing the acid hydrolysis method, and its comparison with the commercially available CNCs (CNC‐C). Furthermore, the CNCs from PPW, SiF, and CNC‐C were subjected to transmission electron microscopy (TEM), Fourier transform electron microscopy, X‐ray diffraction, particle size distribution, and zeta potential analysis. The studied properties of the isolated CNCs are considerably different from the PPW and SiF. The CNCs so formed have been estimated by TEM to be around 10–40 nm wide and length of several micrometers. Fourier transform electron microscopy studies described the removal of the noncellulosic components like lignin, hemicellulose, and pectin substances from the base materials in both the cases by employing acid hydrolysis method. Additionally, nanocomposites of CNC isolated from PPW along with polypropylene (PP) matrix were fabricated using melt blending method followed by injection molding. Maleic anhydride grafted PP (MAPP) acts as a compatibilizer for improving the dispersibility of hydrophilic CNC within the nonpolar PP matrix. The addition of CNC (3 wt%) along with MAPP at 5 wt% showed optimum tensile strength and modulus to the tune of 10.39 and 25.53%, respectively, when compared to their counterparts without MAPP. Dynamic mechanical analysis revealed an increased stiffness of PP in its nanocomposite system due to the addition of CNC. Scanning electron microscopy studies revealed uniform distribution of CNC within the nonpolar PP matrix in the presence of MAPP.

The uncertain climatic changes-related issues in the recent times has led an apprehension for all automotive makers to develop innovative composite materials to reduce vehicle’s fuel consumption. Hence, this review article has given special attention toward the factors that motivated several automakers to undergo research on biocomposites as it plays an important role for biodegradability and sustainability across the globe. In particular, cellulose nanofibers-reinforced composites are the main research focus in the current scenario which can be applied for different automotive applications with numerous advantages and abundant accessibility. Polypropylene (PP) is the emerging polymer in the automotive industry, and many researchers are now mainly focusing their research on PP-based composites which can serve as a boon for different environmental problems faced by the current scenario as depicted by Figure 1. It also reported the recent advancement on the development of innovative composite materials by different automakers with regard to finding suitable actions for reduction of fuel consumption to the recommended confines.