Methanol crosslinking and heat-treatment methods for physical crosslinking of electrospun poly(vinyl alcohol) (PVA) nanofibres were investigated to assess their stability in water. For this purpose, PVAs with low and high molecular weights were selected. Morphology of the crosslinked membranes was characterised by scanning electron microscopy. Crystallinity of the resultant crosslinked fibres were analysed by FT-IR and differential scanning calorimetry. It has been shown that physical crosslinking increases the crystallinity of the fibres. High molecular weight PVA nanofibres showed better stability and better preservation of nanofibrous structure. Stability of the crosslinked membranes was also tested by immersion into water at room temperature and boiling water. Combined methanol and heat treatments at different temperatures and exposure periods were also investigated. Treatment at 180°C HMW PVA nanofibres for longer durations exhibited best results in terms of water stability, although it exhibited somewhat lower swelling ratios as compared to those subjected to only methanol treatment.

Manufacturing natural-based high-performance composites are becoming of greater interest to the composite manufacturers and to their end-users due to their bio-degradability, low cost and availability. Yarn based textile architecture is commonly used in manufacturing these composites due to their excellent formability. However, for using natural based yarn as a reinforcing architecture in high load-bearing structural composite applications, a significant improvement in mechanical performance is required. Particularly, jute fibre yarn suffers from poor mechanical properties due to the presence of a fibrillar network, polysaccharides and other impurities in the fibre. For achieving this, we use aqueous glycine treatment (10%, W/V) on alkali(0.5 %, W/V) and untreated jute yarns for the first time. The glycine treatment on alkali-treated jute yarns (ATG) shows a huge improvement in tensile strength and strain values by almost ∼105% and ∼50 % respectively compared to untreated jute yarns (UT) because of the strong interactions and bonds developed between glycine, alkali and jute yarns. It is believed that the newly developed glycine treated jute yarns will be helpful to promote jute yarns in composite industries where load-bearing is the primary requirement and replace their synthetic counterparts.

No abstract

No abstract

This study detailed two novel processes, the use of stitching and PVA sizing based jute fibre UD preforms, with bamboo slice hybridization for the manufacturing of high-mechanical-performance jute composites, and significant improvement was found.