The concept of zero-energy building is one of the promising ways to improve energy efficiency, resulting in the reduction of greenhouse gas emissions. The use of rigid polyurethane foam (RPUF) has been widely used as insulation material in building panels because of its excellent properties including light-weight, durability, and lower thermal conductivity. This study aimed to determine the effect of mixing conditions on the production of RPUF at varied mixing speeds (300, 500, 1000 rpm) corresponding to its density, mechanical, and insulation properties. It was observed that the well-defined physical structure of RPUF was obtained at the minimum mixing speed of 500 rpm. The foam density changed with the increasing mixing speed, from 39.8 kg/m3 at 500 rpm to 51.30 kg/m3 at 1000 rpm. This might be because of the possible loss of the blowing agent due to excessive mixing speed as noted by the constrained foam expansion and the shorter time for the free-rise process. The thermal insulation property of obtained RPUF was significantly lower than that of conventional building materials like concrete. This research is one of the key technologies to reduce the energy consumption for heating-cooling buildings and thus create a potential strategy for climate change mitigation.
Process parameters are crucial to produce targeted qualities in polypropylene (PP)/clay nanocomposites, due to their roles on the generation of shear and diffusion. Thus, this research aims to observe their effects on structures and properties of PP/clay nanocomposites. Samples were produced by mixing PP, PP grafting maleic anhydride (PP-g-MA), and Cloisite 20A at fixed compositions, 88/9/3 wt%, respectively, in an internal mixer with variations on temperatures (210, 220, 230 °C) and speeds (60, 80, 100 rpm). Effect of mixing parameters on nanocomposite structures and properties were investigated from XRD, SEM and flexural properties. The results showed that all samples had intercalated as well as agglomerated structures. Further analysis on XRD and SEM showed that samples produced at high conditions (230 °C or 100 rpm) had similar structures. In contrast, low setting sample (210 °C and 60 rpm), despite its similarity on dispersion level, had longer agglomerates than that of mixed at high settings. Correlated both increase of d-spacing and agglomerates length to flexural properties suggested that modulus was more influenced by dispersion level, while strength was affected by agglomerates. However, it was worth to note that improvement on d-spacing, with availability of long agglomerates might not guarantee modulus and strength improvement due to low interfacial bonding.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.