Interaction-structure-property relationships in amorphous polymer blends
ABSTRACT Miscibility, structure and property relationships were studied by different techniques for various polymer pairs. Four blends
of polystyrene (PS), styrene-acrylonitrile copolymer (SAN), polycarbonate (PC) and polyphenylene oxide (PPO) [PS/PPO, PS/PC,
PS/SAN and PPO/SAN] were investigated in the entire composition range. Glass transition temperatures were measured by DSC,
mechanical properties were characterized by tensile test, methanol absorption was determined at 50 °C. The Flory-Huggins interaction
parameter (χ) was derived from Hildebrand solubility parameters, and compared to χ-related quantities calculated from the
experimental results. Good correlation was obtained between parameters derived from different methods used for the characterization
of polymer/polymer interaction.
Article: Compatibility and mechanical properties of blends of polystyrene with biodegradable polyesters[show abstract] [hide abstract]
ABSTRACT: Biodegradable polyesters allow the development of acceptable bio-composites and bio-blends from agricultural-based raw materials without impairing their biodegradability and other useful properties. The tensile properties of binary blends of polystyrene (PS) with the biodegradable polyesters polycaprolactone (PCL), d,l-polylactic acid (PLA), and Eastar Bio Ultra (EBU) were investigated. Blend composition ranging from pure PS to pure biodegradable polyester, in 25% increments, were compounded, injection molded, and used in tensile tests, from which the following tensile properties were calculated: yield stress, yield strain, and modulus. In general, the tensile properties of the PS/biodegradable polyester blends were found to be between the values of the corresponding pure components. Comparison of the yield stress and modulus of the blends with 25% PS showed these properties decreasing in the order: PLA/PS>PCL/PS>EBU/PS, which is the exact opposite of the reported trend in the interfacial tensions of these blends. This implies a correlation between tensile and interfacial properties that is consistent with expectations. However, the data also showed the yield strain and modulus of the pure biodegradable polyesters decreasing in the order: PLA>PCL>EBU, which is identical to the observation on the blends with 25% PS. Thus, the observed trend in the tensile properties could also be due to a contribution from the bulk properties of the biodegradable polyesters.Composites Part A: Applied Science and Manufacturing.
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ABSTRACT: This study deals with some results on morphology, miscibility and mechanical properties for polymethyl methacrylate/polycarbonate (PMMA/PC) polymer blends prepared by solution casting method at different concentration between 0 and 100 wt%. Dynamic storage modulus and tan δ were measured in a temperature range from 30 to 180°C using dynamical mechanical analyzer (DMA). The value of the storage modulus was found to increase with the addition of the PC in the matrix. Transition temperature of pure PMMA and pure PC is found to be 83.8 and 150°C, respectively. The result shows that the two polymers are miscible for whole concentration of PC in PMMA. The distribution of the phases in the blends was studied through scanning electron microscopy (SEM). Also the mechanical properties like elongation at break and fracture energy of the PMMA/PC blends increase with the increase in concentration of PC in PMMA.Phase Transitions 12/2009; 82(12):866-878. · 1.01 Impact Factor