Jute fiber (woven fabric, 1 × 1 plain weave) reinforced polypropylene matrix composites were prepared by compression molding with various fiber loading such as 30%, 40%, 46%, 50%, 55% by weight. The mechanical properties such as tensile strength (TS), bending strength (BS), tensile modulus (TM), bending modulus (BM) and impact strength (IS) of the composite were assessed and analyzed. The highest value of TS, BS, TM, BM and IS were 68.1 MPa, 94.1 MPa, 2936 MPa, 4831 MPa and 14.5 kJ/m 2 respectively with 50% fiber loading by weight. It was found that the mechanical properties of the composites were increased with the increase in jute fiber content up to 50% by weight; however, further increase in fiber loading the value decreased. On the basis of fiber content, 50% fiber reinforced composites had the optimum set of mechanical properties. Initially the water absorption rate was higher and then it became slower and static with time. Chemical ageing test with various chemical media such as H 2 O 2 , NaOH, HCl and NaCl were performed up to 168 hours. After first 24 hours the composite samples showed gradual weight gain (%) and then the weight gain was become slow and steady in the chemical solution.
Diisocyanates, particularly toluene diisocyanate (TDI), are useful for the preparation of various polyurethanes with specific applications as leather-like materials, adhesives and insoles, etc. Blocking agents can be used for the operational simplicity and to reduce the hazards of TDI. In this paper, we reported the use of 3-(4-bromo-phenyl)-1H-pyrazole to block toluene diisocyanate (TDI). FTIR, NMR, thermogravimetric analysis, contact angle analysis and differential scanning calorimetry (DSC) were used for the characterization. The effectiveness of the blocking was confirmed by spectroscopic techniques. The DSC thermogram showed that blocked adducts deblock at 240 °C, causing the regeneration of TDI, and causing the diisocyanates to react with polyols of different molecular weights, forming polyurethanes. The characterization of the polyurethanes was performed by infrared spectroscopy, nuclear magnetic resonance spectroscopy, thermogravimetric analysis, differential scanning calorimetry and a contact angle study.
Diisocyanates, particularly toluene diisocyanate (TDI) are useful for the preparation of various polyurethanes with specific applications as leather-like materials, adhesives, insoles etc. Blocking agents can be used for the operational simplicity and reducing the hazards of TDI. In this paper we reported the use of 3-(4-bromo-phenyl)-1H-pyrazole to block toluene diisocyanate (TDI). FTIR, NMR, thermogravimetric analysis, contact angle and differential scanning calorimetry (DSC) and were used for characterization. Effectiveness of blocking was confirmed by spectroscopic techniques. DSC thermogram shows that blocked adducts deblock at 240 °C causing the regeneration of TDI and blocking agents to react with polyols of different molecular weights forming polyurethanes. The characterization of polyurethanes has been done by Infrared spectroscopy, Nuclear magnetic resonance spectroscopy, thermogravimetric analysis, differential scanning calorimetry and contact angle study.
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