00000ctm a22000004i 4500 UP-99796217612121153 Buklod 20230215105418.0 m |o d | ta 160622s xx d r |||| u| (iLib)UPD-00255307905 DENGII rda eng DMLUC LG 995 2015 M37 D45 De los Reyes, Florencio D. author. Development of multi-flame retarders using rice husk-derived silica, phosphorus, and nitrogen-based compounds for polystyrene by Florencio D. De los Reyes ; Magdaleno R. Vasquez, Jr., Peerasak Paoprasert, advisers. Quezon City College of Engineering, University of the Philippines Diliman 2015. 159 leaves in various pagings illustrations 28 cm text rdacontent unmediated rdamedia volume rdacarrier Thesis (M.S. Materials Science and Engineering)--University of the Philippines Diliman December 2015. Available only to those bound by confidentiality agreement. Approved written permission required. Multi-flame retardant systems for polystyrene were developed using surface-modified silica nanoparticles synthesized from locally available rice husks; and phosphorus and nitrogen-based compounds, namely 9, 10-dihydro-9-oxa-10-phosphaphenantrene-10-oxide (DOPO) and melamine, respectively. Amorphous silica nanoparticles with a surface area of 272.7 m2/g and particle sizes ranging from 3 to 25 nm were successfully synthesized from pre-treated rice husk by acid leaching and calcination reactions. The silica powder was mesoporous with a pore size of 3.8 nm. Surface modification of silica nanoparticles was performed using three different silane coupling compounds: 3-aminopropytriethoxy silane (APTES), phenyltriethoxy silane (PHTES), and n-propyltriethoxy silane (PTES), to improve the compatibility between silica and hydrophobic polymer. Functionalization efficiency of aminopropyltriethoxy silane (APTES) reached up to 24.6% with greatly reduced particle aggregations and a narrow size distribution of uniformly spherical particles. It was found that the multi-flame retarder systems applied to polystyrene at a minimum loading concentration improved the limiting oxygen index up to 42.4%, with DOPO exhibiting the best retarding property among the three additives. The silica nanoparticles and polymer composites were characterized using Fourier-transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Dynamic Light Scattering (DLS), Brunauer, Emmett and Teller (TEM), Thermogravimetric Analysis (TGA), Differential Scanning Calorimeter (DSC), Limiting Oxygen Index (LOI) and UL-94 Horizontal and Vertical Tests. Rice hulls Silica content. Fire resistant polymers. Vasquez, Magdaleno R. Jr. adviser. Paoprasert, Peerasak adviser. Thesis FI UP UPD DARCHIVES LG 995 2015 M37 D45 UPD DENG-II LG 995 2015 M37 D45 Thesis