Du Ngoc Uy Lan, Dr.
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/34233
2024-03-28T09:28:09ZPreparation of poly(methyl methacrylate) and polystyrene composite-filled porous epoxy microparticles via in-situ suspension polymerization
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/35031
Preparation of poly(methyl methacrylate) and polystyrene composite-filled porous epoxy microparticles via in-situ suspension polymerization
Du Ngoc Uy Lan, DuNgoc, Dr.; Azhar, Abu Bakar, Dr.; Shingo, Hadano; Baharin, Azahari, Dr.; Yoshiki, Chujo, Prof.; Zulkifli, Ariffin, Prof. Dr.
Both poly(methyl methacrylate) (PMMA) and polystyrene (PS) were synthesized through suspension polymerization, and porous epoxy microparticles (PEMP) were incorporated in-situ during polymerization. It was discovered that the hollow structure available in the PEMP was able to successfully establish an interlocking mechanism with the PMMA and PS matrices, as revealed by SEM micrographs. Due to the epoxy structures, the PEMP could trigger MMA polymerization of two species of PMMA (different in molecular weight), which resided in two different locations, i.e., the outer and inner portions of the PEMP. In contrast, only one species of PS was obtained after polymerization. The glass transition temperature (Tg) for PMMA and PS decreased to approximately 14 and 8 °C, respectively. The thermal stabilities of the resultant composite beads were improved by approximately 56 °C for PMMA-PEMP and by 30 °C for PS-PEMP. It was hypothesized that the unique microstructure of the newly discovered and novel particles was responsible for enhancing the thermal properties of the composites.
Link to publisher's homepage at http://www.sciencedirect.com/
2011-01-01T00:00:00ZPorous epoxy microparticles prepared by an advanced aqueous method
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/35020
Porous epoxy microparticles prepared by an advanced aqueous method
Du Ngoc Uy Lan, DuNgoc, Dr.; Chujo, Yoshiki; Zulkifli, Mohamad ariff, Assoc. Prof. Dr.; Baharin, Azahari, Dr.; Azhar, Abu Bakar, Dr.
This paper reports the synthesis of emulsions of epoxy compounds with various ratios of epoxy, polyamide and calcium carbonate by homogenization in water at room temperature. The emulsion is cured at 80 °C, and during curing the small epoxy droplets in the emulsion coalesce. The cured coalesced epoxy droplets contain holes formed due to water trapped inside them and also due to the difference in curing rates between epoxy molecules on the outside versus inside of the coalesced droplets. The porous epoxy particles are obtained when the cured coalesced epoxy droplets are treated with hydrochloric acid to remove the calcium carbonate. The size of the porous epoxy particles and the number of holes formed depends on the curing rate of the epoxy compound.
Link to publisher's homepage at http://www.sciencedirect.com/
2011-01-01T00:00:00ZProduction of novel epoxy micro-balloons
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/35014
Production of novel epoxy micro-balloons
Du Ngoc Uy Lan, DuNgoc, Dr.; Azhar, Abu Bakar, Dr.; Baharin, Azahari, Dr.; Zulkifli, Mohamad ariff, Assoc. Prof. Dr.
Epoxy micro-balloons are prepared by dropping and stirring of epoxy mixture in heated silicon oil. The mixture of epoxy, curing agent and blowing agent forms sphere particles, which are then blown via the function of blowing agent and simultaneously cured to form epoxy micro-balloons. Different ratio of epoxy and hardener will produce different types of epoxy micro-balloons. Schematic illustrations to produce the epoxy micro balloons are also proposed.
Link to publisher's homepage at http://www.sciencedirect.com/
2009-01-01T00:00:00ZProperties of recycled high density polyethylene/recycled polypropylene blends : Effect of maleic anhydride polypropylene
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/34383
Properties of recycled high density polyethylene/recycled polypropylene blends : Effect of maleic anhydride polypropylene
Maryam Atiqah, A.A.S.; Salmah Husseinsyah, Prof. Madya Ir. Dr.; Firuz, Zainuddin; Du Ngoc, Uy Lan
Polymer blending provides an efficient way to develop new materials with improved properties while preserve the primary properties of the materials at lower cost. The blends recycled high density polyethylene (rHDPE) and recycled polypropylene (rPP) with and without maleic anhydride polypropylene (MAPP) have been investigated. The effect of different blend ratios on tensile properties, morphology and melt flow index were studied. The tensile strength and modulus of elasticity of both blends increased with increased of rPP in the blend ratios but the elongation at break decreased. It was found that the tensile strength and modulus of elasticity of compatibilized rHDPE/rPP blends higher than uncompatibilized blends. The SEM micrograph of tensile fractured surface of compatibilized blends showed better interfacial adhesion and interaction between rHDPE and rPP. The melt flow index of compatibilized blends showed better flowablity than uncompatibilized blends.
Link to publisher's homepage at http://www.ttp.net/
2014-01-01T00:00:00Z