Polyvinyl alcohol (PVA) is a nontoxic and thermoplastic polymer which is completely biodegradable. PVA shows excellent mechanical and thermal properties due to better interfacial adhesion with reinforcing material such as fibers, particles or flakes because of which it can be used for fabrication of composite. PVA based fiber or particle reinforcing composites have gained interest in many applications in different fields. This paper reviews the mechanical and water absorption properties studied by different researcher and some of them were discussed here. The article also focused on the effect on the mechanical properties on PVA based composites with particle or fiber used as reinforcing material at nano/micro level and different polymers used to prepare PVA blend films. The major disadvantage of PVA based composites/films is higher water uptake or solubility in water. To over this negative aspect, many researchers studied crosslinking of PVA based composites/films, which are also discussed in the article. This review concludes that PVA has the potential for use in the synthesis of composites/films with their abundant applications.

In this article, a detailed systematic methodology to fabricate and characterize the diverse properties of soy protein and sisal fiber reinforced green composites has been presented. After fabrication by hand lay-up and solution casting method, these composites with varying sisal fiber weight percentages (0, 3, 4, 5, 6, 7 and 10) were put to various characterization tests. The surfaces of sisal fiber were treated with sodium hydroxide to enhance its interfacial bonding properties. The fabricated samples were examined on the basis of microstructural tests that included the scanning electron microscopy; followed by the mechanical (tensile) and physical (water absorption) tests. Finally, the thermal tests were performed that involved the thermogravimetric analysis, differential thermal analysis and dynamic mechanical analysis tests. The phytagel modified soy protein-based composite with 5 wt.% of sisal fiber content was confirmed to be the best of all compositions under this scrutiny, which was authenticated by the micro-structural and mechanical tests. To further enhance the mechanical, physical and thermal properties of fabricated composites, chitosan coating was applied on them.

In the present investigation, cross-linking of poly(vinyl alcohol) (PVA) was done to enhance the physical, mechanical, and thermal properties of neat PVA. Furthermore, to specifically enhance the mechanical properties, functionalized graphite (via oxidative acidic treatment) particles were used as reinforcement material with varying weight percentages (0, 0.5, 1, 1.5, and 2) in the PVA domain. Fabricated samples are firstly examined by a water absorption test to confirm the formation of cross-linked bonds. Fourier transform infrared spectroscopy is used to confirm the oxidative acid treatment to functionalize the graphite particles. Scanning electron microscopy of the fractured surface of fabricated composites shows strong interfacial bonding taking place between the functionalized graphite and cross-linked PVA, which results in improved mechanical properties of fabricated composites. The maximum ultimate tensile strength is found at 1 wt. % of functionalized-graphite particle reinforcement, which is about 62.5 % higher than neat PVA. The thermal stability of composites was also enhanced with an increase in functionalized graphite particles weight percentage. Dynamic mechanical analysis results show a high value of damping coefficient (tan δ), which is about 0.573 for cross-linked PVA, which confirms a high damping character. Therefore, these materials could be potentially used to minimize noise transmission as a vibration isolator and shock absorber and in nanocoating applications.

Basalt fiber is emerging out the new reinforcing material for composites. To overcome some of the disadvantages of fibers such as poor bonding to polymers, low thermal stability and high moisture absorption fiber characteristics are modified with chemical, thermal and additive treatments. Chemical treatment corrosive resistance to alkali and acid were investigated which were used to clean and modify the surface of fiber for higher bonding with resins. To improve the thermal stability and reduce moisture uptake thermal treatment such as plasma and non thermal plasma were used which increased the surface roughness and change the chemical composition of surface of basalt fiber. Additive treatment is used to improve the mechanical properties of fibers, in basalt fiber additive treatment was done with SiO ₂ additive because of its chemical composition which contains major content of SiO ₂ . In present investigation review on the effect of different treatment such as chemical, thermal and additive were studied. Effect of these treatment on chemical composition of the surface of basalt fiber and corrosion to acidic and alkali solution were studied with their effect on mechanical properties of basalt fiber and their composite.