Determination of Hexabromocyclododecane in Expanded Polystyrene and Extruded Polystyrene Foam by Gas Chromatography-Mass Spectrometry

A gas chromatography-mass spectrometry (GC/MS) method for the determination of hexabromocyclododecane (HBCD) in expanded polystyrene and extruded polystyrene foam (EPS/XPS) was developed. The EPS/XPS samples were ultrasonically extracted with acetone and the extracts were purified by filtration through a microporous membrane (0.22 μm) and solid-phase extraction. The samples were analyzed using a GC/MS using the selected ion monitoring mode. The ions 157, 319 and 401 were selected as the qualitative ions, while ion 239 was chosen as the quantitative ion. An HBCD standard working solution with a concentration range of 1.0–50.0 mg/L showed good linearity. The detection limit of HBCD was 0.5 mg/kg, meeting the LPC limit (<100 or 1000 mg/kg). Six laboratories were selected to verify the accuracy of the method, and 10 samples were tested. The interlaboratory relative standard deviation range was 3.68–9.80%. This method could play an important role in controlling HBCD contamination in EPS/XPS.

Building Systems Based on Foamed Modified Polymers

Systems of floor insulation on the ground, isolation of roads and shallow foundations suggest the use of heat-insulating products resistant to moisture, the minerals contained in it, having low heat conductivity and water absorption and relatively high strength for compressive loads.The aim of the research was to study the possibility of using mineral substances containing crystalline water as a dispersed component. Firstly, such compounds as a reinforcing component increase the strength characteristics of products. Secondly, being flame retardants, they contribute to increasing the fire safety of materials and building systems in which these materials are used. To achieve this goal, two particular tasks were set: determination of the optimal consumption of mineral modifying additives; assessment of exploitative stability of the received products. It was found that the introduction of a mineral modifying additive can significantly increase the compressive strength by 10% deformation of samples from extruded polystyrene foam. The exploitative stability of products with a mineral additive varies slightly and depends on its consumption and uniform distribution in the product matrix. The effect of additive consumption on the change in the thermal conductivity of products has not been established. A nomogram has been built which allows one to evaluate the properties of products and determine the optimal consumption of a modifying additive.Systems of using products from modified extruded polystyrene foam in monolithic foundations with insulation for buildings erected on problem soils are considered.

Research work of Prof. Tomita, including: 1. Examination of environmental vibration measurement using vibration control rubber on carpet. 2. Measures against floor impact sound by heavy-impact source using storage furniture with tatami. 3. Study on tatami mat considering safety when falling in case of falling collision and sound insulation performance. 4. Research on evaluation method and evaluation rank for vertical vibration

A tatami is a type of mat used as a floor material in many rooms in Japan. They are also used in training rooms, such as in a dojo or martial arts, and are often covered with woven straw. Tatami mats were used as flooring materials for buildings in the Kamakura period (c. 1185) and have a long history. Tatami is often used in the Japanese-style room of today's homes. Generally, tatami mats are 55 mm thick; some mats are made of mostly straw and some made of insulation board and extruded polystyrene foam. The surface of both types of mats is covered with tatami facing. More recently, tatami mats made of insulation board and extruded polystyrene foam are used in homes. Despite their presence in Japanese buildings, there are several problems associated with tatami mats and other floor materials. One of the potential problems concerns the safety of individuals who fall on the mats, while another is the sound created by impact on the mats, such as when people walk or run across them. Research is underway to find effective ways of improving the sound insulation performance of floor materials at the same time as considering the safety of the inhabitants of the buildings with the mats in them. One team, which is investigating means of improving tatami mats and the materials used to build them, is based at the College of Science and Technology in Nihon University, Japan. Led by Professor Ryuta Tomita, the team is engaged with several projects revolving around overcoming heavy-weight floor impact sound insulation performance and safety of individuals who fall on tatami mats.

Effects of surfactants on mechanical and thermal properties of soy-based polyurethane foams

Polyurethane foams are widely used for insulation applications due to their high insulation properties as compared to conventional materials such as extruded polystyrene foam and mineral wool. In this study, soy-based polyurethane foams were prepared using five different surfactants while keeping other components such as soy-based polyol, diisocyanate, catalyst, and blowing agent (water) constant. Prepared samples were tested for mechanical and thermal properties to evaluate the effect of different surfactants used in varying quantities. The morphology of the foam samples was observed using a scanning electron microscope. Seventeen fold reduction in the cell size was observed with an increase in the amount of surfactant from 0.5 to 5.0 g. Samples with higher amounts of surfactant also exhibited a higher number of closed cells. Better thermal insulation was observed for samples with 2.0 and 5.0 g of surfactant as compared to samples with 0.5 g of surfactant. A similar trend was observed in the mechanical strength, moisture absorbance, and density of the fabricated foam samples.

Measurement of the Shear Properties of Extruded Polystyrene Foam by In-Plane Shear and Asymmetric Four-Point Bending Tests

The shear modulus and shear strength of extruded polystyrene foam were obtained by the in-plane shear and asymmetric four-point bending tests. In addition, the test data were numerically analysed, and the effectiveness of these tests was examined. The numerical and experimental results suggest that the shear modulus and shear strength obtained from the in-plane shear test are significantly smaller than those obtained from the asymmetric four-point bending test because the influence of the stress concentration was less significant. Although the in-plane shear test is standardised in ASTM C273/C273M-11, it is considerable to adopt the asymmetric four-point bending test as another candidate for obtaining the shear properties of extruded polystyrene foam.