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Rice husk ash (RHA) and silica-filled nitrile rubber (NBR) composites were prepared using a laboratory-size two-roll mill. The mechanical properties and water absorption were studied before and after being exposed to gamma irradiation from 25 to 200 kGy. The tensile strength increased with RHA up to an optimum filler loading (20 phr) and (30 phr) for a silica-filled NBR composite. The tensile strength for the irradiated composite filled with 30 phr silica increases with an increase in irradiation doses up to 100 kGy. The presence of silica filler phase that has a higher electron density than the polymer matrix will likely result in an increase in cross-linking or scissioning and better dispersion in the matrix. Water absorption studies indicate that the irradiated NBR composite filled with silica has lower water absorption rather than the composite filled with

This study focuses on the partial substitution effect of ordinary Portland cement (OPC) by different ratios of waste glass powder (5%, 10%, and 20% by weight of cement) on the performance of blended cement mortars. The hardened blended cement mortars were first cured under tap water for different time intervals 3, 7, 28, and 90 days. However, the effect of addition of 10% styrene‐acrylic ester as well as the influence of different doses of gamma rays on the physico‐chemical and mechanical properties of polymer modified blended cement mortar specimens were discussed. Compressive strength, total porosity, and water absorption percentages were measured. The experimental results showed that the physico‐chemical and mechanical properties of blended cement mortars specimens improved as the waste glass content increases up to 20%. In addition, irradiated SAE blended cement mortar composites containing 20% waste glass showed an enhancement in its properties as compared to neat cement (0%WG content) composites. The results were confirmed by X‐ray diffraction, thermogravimetric analysis, and scanning electron microscopy. POLYM. COMPOS., 39:985–996, 2018. © 2016 Society of Plastics Engineers

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This study aimed at using polyurethane foam waste in the production of lightweight white cement pastes by a partial replacement of white cement with different ratios of polyurethane foam waste (10%, 20%, 30%, and 40%) based on the weight of cement. The lightweight white cement pastes specimens in addition to conventional white cement paste were cured under tap water for 7 and 28 days. The physical, mechanical, and thermal properties were evaluated. The results showed that the specimens cured for 28 days achieved better properties as compared to the specimens cured for 7 days. Furthermore, at each curing age the specimens of lightweight white cement pastes showed relatively lower properties as compared to the conventional white cement paste and as the polyurethane waste content increased, the properties in terms of compressive strength and bulk density decreased while the total porosity percentage increased especially at higher ratios. On the other hand, the effects of styrene–butadiene rubber latex and irradiation dose on the properties of irradiated polymer impregnated lightweight white cement composites have been investigated. The results confirmed that the impregnation of the hardened lightweight white cement pastes with styrene–butadiene rubber latex and their exposure to different doses of gamma rays (50, 100, 150, and 200 kGy) showed a gradual improvement in the mechanical and physical properties up to 150 kGy and then started to decrease at 200 kGy. Characterization of some selected specimens was carried out by the studying of thermogravimetric analysis, scanning electron microscopy, and X‐ray diffraction. J. VINYL ADDIT. TECHNOL., 25:328–338, 2019. © 2019 Society of Plastics Engineers