1,720,975 research outputs found
Thermo-mechanical and Morphological Characterization of Plasticized Poly[(R)-3-hydroxybutyric acid]
No full textThermal Behavior of Composites Based on Poly(vinyl alcohol) and Sugar Cane Bagasse
No full textPoly(vinyl alcohol) (PVA) and sugar cane bagasse (SCB) mixtures have been formulated as aimed at the production of hydro-mulching composites and melt processed biobased composite items. Glycerol and urea have been proposed as suitable plasticizers and eventually, in the case of urea, for the realization also of slow release fertilizing hydro-mulching. The investigation of thermal stability of raw components and relevant mixture is an important parameter to be assessed in view of processing and ultimate applications. PVA/SCB composites appeared suitable for melt processing up to 200 °C. The urea containing PVA/SCB composites while resulted particularly suited for hydro-mulching applications did not appear processable from the melt, due to urea thermal instability
Thermal Characterization of Three Component Blends for Hot-Melt Adhesives
No full textraditional solvent-based adhesives used in the foot-wear industry have been demonstrated as harmful to the workers' health and environment. Solvent-free three-component adhesives (hot-melt adhesives or HMAs) for various applications including the leather and footwear industry are becoming more and more attractive. Thus, the formulation of a three-component HMA was realized in this study. Thermogravimetry, differential scanning calorimetry, and the apparent strength of the adhesive bond were used to investigate the relationship between their properties and the polymer/wax/resin compositions. The thermal stability of HMA formulations was determined and compared with thermal traces based on an additive weight computation of the single components' thermal profiles. All HMA formulations showed a direct relationship between the glass-transition temperature and the apparent adhesive shear strength at the leather-rubber interface
Environmentally Degradable Plastics: Thermal Behavior of Polymer Blends Based on Waste Gelatin
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Factorial Design in Optimization of PHAs Processing
No full textPoly(hydroxyalkanoate)s (PHA)s, as all melt-processed polymers, may undergo thermal degradation at temperatures close to the melting point. The primary purpose of the present study is to screen out process variables on the basis of a factorial design for two variables at two levels. The investigated parameters for PHA polymer samples processed in a torque rheometer were structure of PHA, processing temperature, and rotor speed. For polymers processed by compression molding, only the first two variables were considered and purification. The main effects and possible interactions were verified by the changes of molecular weight and thermal properties, as detected by DSC and TGA. It was observed that molecular weight decreased up to about 50 % while the thermal properties did not appreciably change
Hybrid Hydrogels Based on Poly(vinylalcohol)-Chitosan Blends and Relevant CNT Composites
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