Effect of Recycling on the Rheological, Mechanical and Optical Properties of Polycarbonate
The research was aimed at analyzing the polycarbonate scrap arising during production and its possible secondary utilization. The analysis of morphological, rheological and thermal data revealed significant differences between the original pellets and the reground material obtained from injection molded parts. Test specimens were injection molded from various mixtures of the virgin and the reground material, and their mechanical and physical properties were analyzed. Based on the results the reground material may be used in less than 20% proportion, as the mechanical properties of the products do not deviate significantly from those of the products made from virgin polycarbonate.
Plastics' key role in energy-efficient building
Plastics-based solutions are widespread in the building industry, as the benefits they brought are multiple: insulation, protection from wind and weather, easy refurbishment, attractive new design or efficient energy management. Plastic pipes for heating and water have proved to be superior to conventional piping systems (more flexible, rust-free, anti-scale deposits, etc.) for a long time. Window frame profiles made of polyvinyl chloride (PVC), one of the most widely used plastic in building industry, provide better thermal insulation, making them suitable for use in passive houses as the energy consumption is reduced dramatically. Other polymer systems may also improve energy management for facades, walls and roofs. Composites or sandwich elements made of expanded polystyrene (EPS) filled with graphite particles or polyurethane (PU) rigid foams are used on walls or on roofs, as well as below the ceiling to provide climatic regulation. The surface of front doors, window frames and facades can be coated with UV-resistant acrylonitrile styrene acrylate (ASA) films so as to guarantee long-term protection against weathering. Roof glazing with thermal protection made of polymethyl methacrylate (PMMA) or polycarbonate (PC) multi-wall sheets enables interior spaces to stay pleasantly cool without having to dispense with daylight, and reduces the cost for heating and cooling. Moreover, as the solar heating market is steadily growing, the very promising field of large area, light-weight organic photovoltaic panels has emerged for plastics. Polyvinyl fluoride (PVF) films have been used successfully for the backsheet of photovoltaic modules thanks to their weather and UV-resistance, and high barrier properties against moisture. Light-resistant thermoplastic polyurethanes (TPU) are expected to permit to switch from batch-manufacturing to continuous production, lowering expenses accordingly. Furthermore, new efficient manufacturing methods for large-surface modules on flexible low-cost substrates are under development. Finally, intensive research efforts are currently going on into semiconducting organic materials with high thermal and photochemical resistance, which are intended to replace today's silicon, whereby they absorb sunlight and convert it into electric power. At last, organic Phase Change Materials (PCM) such as HDPE or paraffin compounds provide a new horizon for passive thermal energy storage in bioclimatic architecture, and will contribute to make buildings even more energy-efficient in the future.
Deformation of PC/ABS alloys at elevated temperatures and high strain rates
Abstract The objective of this paper is to experimentally study the deformation behavior of the alloys of polycarbonate (PC) and acrylonitrile–butadiene–styrene (ABS) at elevated temperatures and high strain rates. Four kinds of PC/ABS alloys with the ratio of PC to ABS being 80:20, 60:40, 50:50 and 40:60 and three different strain rates 8.0 × 102 s−1, 2.7 × 103 s−1 and 1.0 × 104 s−1 are considered. The Split Hopkinson Pressure Bar (SHPB) experiments are carried out at 293 K and 343 K, respectively. The curves of engineering stress and engineering strain and true stress and true strain are obtained for the PC/ABS alloys at different temperatures and different strain rates, respectively. The effects of temperature, strain rate and the fraction of ABS on the deformation behavior of PC/ABS alloys are discussed in details, and then a temperature and strain rate-dependent phenomenological constitutive model for PC/ABS alloys is developed.