Natural fibers are getting attention from researchers and academician to utilize in polymer composites due to their ecofriendly nature and sustainability. The aim of this review article is to provide a comprehensive review of the foremost appropriate as well as widely used natural fiber reinforced polymer composites (NFPCs) and their applications. In addition, it presents summary of various surface treatments applied to natural fibers and their effect on NFPCs properties. The properties of NFPCs vary with fiber type and fiber source as well as fiber structure. The effects of various chemical treatments on the mechanical and thermal properties of natural fibers reinforcements thermosetting and thermoplastics composites were studied. A number of drawbacks of NFPCs like higher water absorption, inferior fire resistance, and lower mechanical properties limited its applications. Impacts of chemical treatment on the water absorption, tribology, viscoelastic behavior, relaxation behavior, energy absorption flames retardancy, and biodegradability properties of NFPCs were also highlighted. The applications of NFPCs in automobile and construction industry and other applications are demonstrated. It concluded that chemical treatment of the natural fiber improved adhesion between the fiber surface and the polymer matrix which ultimately enhanced physicomechanical and thermochemical properties of the NFPCs.

Poly (lactic acid) (PLA)/chitosan (CS) natural polymer/epoxidised natural rubber (ENR) composites were successfully prepared through a solution casting method. The morphological characteristics of fabricated composites were investigated by scanning electron microscopy (SEM) and optical microscopy. The microstructure of PLA/ENR was significantly altered with the addition of CS. SEM analysis of composites fractured surfaces revealed smooth and homogeneous texture and good dispersion of CS. However for 15 wt% CS composites, the phase segregation and poor adhesion between the polymers were observed. Fourier transform infrared spectroscopy revealed some levels of attractive interaction between CS, PLA, and ENR in the composites. The mechanical properties of composites in terms of tensile strength and tensile modulus were significantly improved with the addition of CS into the matrix while the percent elongation at break decreased. The tensile strength increased up to 5 wt% CS loading for both PLA/CS and PLA/ENR/CS and thereafter decreased while Young’s modulus increased up to 10 wt%. However, when the CS content was increased to 15 wt%, the tensile strength and tensile modulus were slightly decreased. These improvements were attributed to good dispersion of CS at the optimum filler levels and attractive interaction between the composites components.

This paper presents the result of investigations carried out in studying the emission and performance of diesel engine using the castor biodiesel and its blend with diesel from 0% to 40% by volume. The acid-based catalyzed transesterification system was used to produce castor biodiesel and the highest yield of 82.5% was obtained under the optimized condition. The FTIR spectrum of castor biodiesel indicates the presence of C=O and C–O functional groups, which is due to the ester compound in biodiesel. The smoke emission test revealed that B40 (biodiesel blend with 40% biodiesel and 60% diesel) had the least black smoke compared to the conventional diesel. Diesel engine performance test indicated that the specific fuel consumption of biodiesel blend was increased sufficiently when the blending ratio was optimized. Thus, the reduction in exhaust emissions and reduction in brake-specific fuel consumption made the blends of caster seed oil (B20) a suitable alternative fuel for diesel and could help in controlling air pollution.

The utilization of waste fly ash and natural jute fiber has drawn attention to producing sustainable concrete. However, there is a lack of studies to analyze the synergistic effect of jute fiber and fly ash on the properties of concrete. Hence, the aim of this study is to investigate the combined effect of fly ash concentration and the different sizes of jute fiber on the fresh, hardened, and non-destructive testing properties of concrete. Concerning the purpose, the concrete mixes were prepared with 0.2 % and 0.4 % jute fiber incorporating 0 %, 5 %, 10 %, and 15 % replacement of cement by fly ash in concrete. For the assessment of properties, slump, density, and compacting factor test was conducted at the fresh state of concrete, whereas mechanical properties such as compressive, splitting tensile, and flexure strength test were conducted at 7 and 28 days. In addition, the non-destructive test (NDT) was also carried out to predict the destructive compressive strength by rebound hammer at 28 days. The microstructure property of optimum mix concrete was analyzed by scanning electron microscopy (SEM). It is observed that the incorporation of jute fiber decreased the slump, density, and compacting factor but increased the compressive, splitting tensile, and flexure strength, whereas the fly ash improved both fresh and hardened properties. Compared to the standard mix, fly ash-based JFRC mixtures have compressive strength improvements varying from 1.7 % to 25.9 %. The 10 % fly ash and 0.2 % volume of jute fiber exhibited a maximum of 11.64 % and 10.72 % splitting tensile and flexural strength enhancement at 28 days, respecting the control mix. In addition, the NDT strength assessment obtained 5.5 % less than destructive strength on average. From the SEM point of view, it is obtained that the 10 % fly ash with 0.2 % jute fiber composition matrix exhibits a better bonding interface and the cracking resistance nature of the concrete mix.