Poly(vinyl alcohol) (PVA) composites with 10, 20, 33, and 50 wt % of coconut shell (CCS) powder were prepared by aqueous mixing. The solution was casted as films and tested for physicomechanical properties such as tensile, tear, burst strengths, density, moisture content, moisture vapor transmission rate, moisture analysis; solubility resistance in water, 5% acetic acid, 50% ethanol, sunflower oil; swelling characteristics in 50% ethanol, sunflower oil; and thermal characteristics by differential scanning calorimetry. The PVA/CCS powder composite films show enhancement in elastic modulus, degradability, solubility resistance in water, 5% acetic acid, 50% ethanol, and moisture resistance. However, the introduction of CCS powder varies the tensile strength and affects percentage of elongation, tear and burst strengths, moisture content, density, and swelling capacity.

A series of poly(methyl methacrylate) (PMMA) blends have been prepared with different compositions viz., 5, 10, 15, and 20 wt % ethylene vinyl acetate (EVA) copolymer by melt blending method in Haake Rheocord. The effect of different compositions of EVA on the physico-mechanical and thermal properties of PMMA and EVA copolymer blends have been studied. Differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) has been employed to investigate the phase behavior of PMMA/ EVA blends from the point of view of component specific interactions, molecular motions and morphology. The resulting morphologies of the various blends also studied by optical microscope. The DSC analysis indicates the phase separation between the PMMA matrix and EVA domains. The impact strength analysis revealed a substantial increase in impact strength from 19 to 32 J/m. The TGA analysis reveals the reduction in onset of thermal degradation temperature of PMMA with increase in EVA component of the blend. The optical microscope photographs have demonstrated the PMMA/EVA system had a microphase separated structure consisting of dispersed EVA domains within a continuous PMMA matrix.

Blends of poly(methyl methacrylate) (PMMA) with different composition viz., 5, 10, 15, and 20 wt % of ethylene-vinyl acetate (EVA) copolymer were prepared by extrusion in a corotating twin screw extruder. These prepared PMMA/EVA blends have been characterized for physicomechanical properties such as density, surface hardness, izod impact strength, tensile strength, tensile elongation, and tensile modulus. The chemical aging and heat aging tests were performed on the blends by exposing them to different chemical environments and to 808C for 168 h respectively. The influence of chemical aging and heat ageing on the mechanical performance of PMMA/ EVA blends has been studied. The PMMA/EVA blends were also characterized for thermal properties such as vicat softening point (VSP) and melt flow index (MFI). That means significant improvement in impact strength of PMMA was noticed after incorporation of EVA into PMMA matrix and it lies in the range 19.1-31.96 J/m.

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ABSTRACT:Blends of polyamide-6 with 5, 7.5, 10, 15, and 20 wt % of polyvinyl alcohol (PVA) were prepared by the extruding in a corotating twin-screw extruder. The extrudate strands were cut into pellets and injection-molded to make test specimens. These specimens were tested for physico-mechanical properties such as tensile strength, impact strength, density, water absorption, hardness, and thermal characteristics by differential scanning calorimetry, heat distortion temperature (HDT), vicat softening point (VSP), and melt flow index. The prepared blends show enhanced biodegradation, water absorption, and density, but it is observed that the introduction of PVA into the polyamide-6 matrix shows considerable reduction in tensile strength, impact strength, HDT, VSP, and hardness initially, but subsequent addition does not show significant reduction because of the enhanced interaction between amide groups of polyamide-6 and hydroxyl groups of PVA.