Du Ngoc Uy Lan

San Jacinto College · Department of Chemistry

The use of carbamate to foam epoxy depends significantly on the precured modulus to stabilize the cellular structure. The optimum precured modulus is developed from the reaction of epoxy resin and the neat amine. The selection of the neat amine relies on its reaction temperature with epoxy, which is required to be below the decomposition temperatur...

Expanded polymeric beads offer the advantage of being able to produce parts with complex geometries through a consolidation process. However, established polymeric beads are made of thermoplastics, deform and melt beyond their temperature services. In this manuscript, a new technique is proposed to fabricate expandable epoxy beads (EEBs), then expa...

The foaming of epoxy resin is a challenge process in optimizing the flow foaming and curing to obtain a homogeneous cellular structure. This study presents a new method for preparing of epoxy foams, which is called solid-state carbamate foaming technique. The epoxy resin was formulated based on epoxy, hardener (amine or polyamide) and carbamate. Th...

Foaming an epoxy is challenging because the process involves the curing reaction of epoxy and hardener (from monomer to oligomer, to a gel and a final three-dimensional crosslinked network) and the loading of gas phase into the epoxy phase to develop the cellular structure. The latter process needs to be carried out at the optimum curing stage of e...

Process temperature greatly affects the decomposition behavior of a blowing agent, and changes the structure of the porous epoxy. This paper investigates the effect of processing temperature on the decomposition rate and volume of decomposing gases from ammonium bicarbonate as well as the properties of porous epoxy micro-bead through a single epoxy...

The use of amine-based carbamates with their dual function, acting as amine curing agents and CO2 blowing agents after their decomposition without by-products, are promising for ecofriendly epoxy foams as high-performance materials. However, controlling cell morphology requires a proper adjustment of the viscosity at the foaming step. The viscosity...

The use of amine-based carbamates with their dual function, acting as amine curing agents and CO2 blowing agents after their decomposition without by-products, are promising for ecofriendly epoxy foams as high-performance materials. However, controlling cell morphology requires a proper adjustment of the viscosity at the foaming step. The viscosity...

Foaming an epoxy is challenging because the process involves the curing reaction of epoxy and hardener (from monomer to oligomer, to a gel and a final three-dimensional crosslinked network) and the loading of gas phase into the epoxy phase to develop the cellular structure. The latter process needs to be carried out at the optimum curing stage of e...

Conductive composite requires a well dispersion of conductive filler, which is this difficult to be achieved low content of filler for high density conductive filler. This work investigates the effect of carbon black and graphite on the morphology and conductive properties of conductive epoxy micro-porous. The conductive epoxy micro-porous was prep...

This work proposes a new understanding of the side effect of mineral fillers in polymer compounding that caused different levels of thermo‐mechanical degradation (TMD) during extrusion. Three mineral fillers, silica (random shape), kaolin (platy), and wollastonite (needle‐like), were selected and compounded with the polypropylene‐ethylene copolymer...

This study is to understand the side effect of wollastonite fillers in polymer compounding that caused different levels of thermo-mechanical degradation (TMD) during extrusion. Wollastonite has a needle-like structure with different ratio of L/D; it compounded with the polypropylene-ethylene copolymer (PPcoE) using a twin-screw extruder. The effect...

The research proposed an aqueous emulsion foaming process to produce a viscoelastic epoxy foam having a density of 0.33–0.36 g/cm³ from the polyamide–epoxy adduct, which uses a reverse ratio of epoxy and polyamide hardener. The process is simple, economical and uses no surfactant, thanks to the emulsifying ability of polyamide hardener. Firstly, th...

The present study focuses on the processing and properties of epoxy foams by the use of CO2 blocked hardener N-aminoethylpiperazine (B-AEP) and different resins. Although some studies described the foaming with carbamates, little attention has been given to the interaction of resin properties (such as viscosity) on the foaming performance. Therefor...

This study focused on the effect of PTFE powder on the bio- POPU foam properties. It was found that bio-foam composite produced using closed mould method obtained the desired density and porosity properties. The SEM morphology showed that bio-foam has homogenous cell structure with regular shape cells’ interconnection. Apparently, bio-composite foa...

Currently, conductive porous is used in composite to reduce the conductive filler loading and improve the conductive property. In this study, conductive epoxy porous (CEP) had been fabricated by single emulsion technique from the mixture of epoxy, polyamide hardener, carbon black filler and sodium bicarbonate. Epoxy mixture was dropped into a heate...

Cardanol-furfurylamine benzoxazine (CFB) is a bio-based resin thanks to cardanol as a by-product of cashew nut shell liquid. Polybenzoxanize obtained from CFB exhibited high thermal stability, however, it requires a high thermal curing temperature. This research was aimed to reduce the curing temperature of CFB by blending it and diphenolic acid-an...

Oil palm biomass waste is the most critical issue for palm oil industry so the solution for this identified problem is essential. One of the most effective solutions is the use of oil palm biomass as fillers in polymer composites. This practice not only concerns on the cost issue but mainly also on the reinforcing effect of oil palm biomass. In fac...

The characteristics of waste oil palm empty fruit bunch fiber (OPEFB) including fiber morphology and mechanical properties were investigated for use as reinforcement in polymer composites. The mechanical properties of the OPEFB fiber were determined by the single fiber tensile test which was carried out at different span lengths (20, 40, and 60 mm)...

Oil palm biomass waste is the most critical issue for palm oil industry so the solution for this identified problem is essential. One of the most effective solutions is the use of oil palm biomass as fillers in polymer composites. This practice not only concerns the issue of cost, but also the reinforcing effect of oil palm biomass. In fact, only o...

Bio-foam was produced from palm oil-based polyol (POBP) and methylene diphenyl diisocyanate (MDI) with weight ratio of 1:1. The effect of opened mould (as free rise) and closed mould (control expansion) was investigated. Different densities of bio-polyurethane foam (0.3, 0.4 and 0.5 g.cm⁻³) were prepared using the closed mould system. The effect of...

The physical and degradation properties of polylactic (PLA)/thermoplastic starch (TPS) blends after TPS modification with citric acid (CA) were investigated. The interfacial adhesion between the PLA and TPS was expected to improve, thus enhancing the physical properties of the PLA/TPS blends. The tensile strength and Young’s modulus for PLA/TPS ble...

Liquid natural rubber (LNR) was used as the toughening agent to overcome the brittleness of epoxy thermoset matrix. The LNR were prepared by using depolymerization method. The experiment was consist of two parts of study, first, epoxy filled with carbon black to get the optimun 15 vol.% content of carbon black (CB). Second, epoxy with various amoun...

The epoxy composite hollow microspheres (ECHM) was prepared by single emulsion technique. Porofor Toluenesulfonyl hydrazide (TSH) 75 was used as blowing agent. Carbon black was used as filler for polyamide-epoxy adduct matrix, which was reverted ratio of 1:2 epoxy to polyamide. The epoxy mixture (internal phase) was dropped and stirred into a heate...

The research focused on the usage of waste oil palm biomass such as empty fruit bunch fibre (EFB), dried palm shell (DPS) and palm kernel shell (PKS) to produce palm oil-based polyurethane (POPU) composite foams, and applied them as sandwich cores. The sandwich cores were attached with jute/epoxy composite facesheets to fabricate high-strength bio-...

Carbon black-filled epoxy porous (CBEP) was fabricated by using single emulsion technique. Mixture of epoxy, polyamide hardener, sodium bicarbonate (as blowing agent) and carbon black (as conductive filler) was dropped into a heated corn oil at 160 °C (containing free of polyunsaturated fatty acids). The epoxy-oil system was stirred at 1000 rpm for...

Phase selective localization of silica in polymethyl methacrylate/ ethyl vinyl acetate (PMMA/EVA) composite controls the concentration of silica in each PMMA and EVA phases and affects the mechanical properties of the composite. In order to produce the different concentration of silica in each polymer phase, pre-dispersion of silica into single pha...

This paper presents on the structural changes associated with mechanical activation of limestone (CaCO3) and dolomite (CaMg(CO3)2) from Perlis, Malaysia via Planetary ball milling. Operational variables include 3 level of revolution speed (250, 350 and 450 rpm), grinding durations (30, 60 and 90 min) and ball to powder ratios BPR (3:1. 6:1 and 9:1)...

Empty fruit bunch fiber (EFB), an abundant biomass waste from the palm oil industry, is used to reinforce palm oil-based polyurethane foam (POPU), and the mechanical properties of the composite foams are also assessed. The fiber-foam interfacial adhesion is also investigated by SEM images and Fourier transform infrared spectrometry. The results sho...

Carbonate rocks were mechanically activated in a high energy planetary ball mill using dry grinding method. The fine grinding test works were carried out with the same ball to powder ratio (9:1) at three levels of revolution speed (250rpm, 350rpm and 450rpm) and grinding time (30min, 60min, 90min) respectively. The chemical composition and elementa...

Porous epoxy was fabricated using natural rubber latex (NRL) as the void template. In this study, two mixing sequences were selected: epoxy, hardener, and then latex (EHL) and epoxy, latex, and then hardener (ELH). The extraction process was carried out to extract the latex particles from the cured epoxy sample using toluene as extraction medium wi...

Polylactic acid (PLA) is most known as a biodegradable plastic, often faces such a problem mainly related to flexibility. In order to improve the brittleness of PLA and to produce biodegradable plastic with good combination of cost and performance, we have focussed here on adding thermoplastic starch (TPS) within the PLA matrix. To improve the inte...

Carbonate rocks were mechanically activated in a high energy planetary ball mill using dry grinding method. The fine grinding test works were carried out with the same ball to powder ratio (9:1) at three levels of revolution speed (250 rpm, 350 rpm and 450 rpm) and grinding time (30 min, 60 min, 90 min) respectively. The chemical composition and el...

Carbonate rocks were mechanically activated in a high energy planetary ball mill using dry grinding method. The fine grinding test works were carried out with the same ball to powder ratio (9:1) at three levels of revolution speed (250 rpm, 350 rpm and 450 rpm) and grinding time (30 min, 60 min, 90 min) respectively. The chemical composition and el...

Polymer blending is an efficient way for tailoring products with required set of properties and is often more cost effective when recycling. In this study, the effect of different blend ratios on tensile properties, morphology and crystallinity of recycled poly(propylene) (rPP) and recycled high density polyethylene (rHDPE) were studied. Polyethyle...

Epoxy shape memory foam (ESM) was produced by an advanced aqueous method. Mixture of epoxy, sodium bicarbonate, hardener and ammonium chloride was premixed and emulsified in distilled water by using high speed stirring (at 1200 rpm). The content of sodium bicarbonate used was 5, 10, 15 and 20 phr. Besides that, ammonium chloride was used (based on...

Low density polyethylene (LDPE) and natural rubber (NR) filled silica composites were prepared by using internal mixer (Brabender) at 150oC and 50 rpm for 10 minutes. Silica was incorporated into polymer matrix by three mixing routes by using Brabender. In mixing I, filler was added into LDPE/NR blend. In mixing II, filler was added prior to LDPE,...

Single emulsion system was applied to prepare epoxy droplets in heated corn oil, which composes of epoxy, polyamide, blowing agent and conductive filler. The use of reversed ratio of epoxy and polyamide as called polyamide-epoxy adduct induces a low crosslink density of the cured matrix, so that it was able to be cured and blown simultaneously unde...

Epoxy micro-porous (EMP) was produced from epoxy, polyamide and calcium carbonate by emulsion polymerization. The emulsifying process of epoxy mixture and water was carried out using homogenizer. The effect of emulsifying speed toward the emulsion stability and structural formation of EMP was investigated through its morphology and compression prop...

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 differe...

Kaolin’s effect on rheological behaviour of polypropylene-kaolin composites was investigated. The research found that not only the kaolin content influence the rheological behaviour but also the compounding using internal mixer and twin screw extruder. In details, viscosity and shear stress increased with addition of kaolin content. These character...

A natural fiber sandwich was constructed from palm shells/polyurethane core and jute woven/vinyl ester facesheets by the in-situ sandwich process (core and panel prepared simultaneously). The polyurethane sandwich core was reinforced by hybrid shell systems of dried palm shell (DPS) and palm kernel shell (PKS) (50P-50D, 25P-75D), and single shell s...

The effect of blends ratio of Recycled Polypropylene (rPP) and Recycled High Density Polyethylene (rHDPE) on tensile properties of rPP/rHDPE geo-composites were studied. The increasing of rHDPE ratios has decreased the tensile strength and elongation at break of rPP/rHDPE geo-composites, but the modulus of elasticity increased. The effects of rPP r...

Porous epoxy was fabricated by using natural rubber latex particles as the void template which were extracted after by different types of extraction mediums such of distilled water and toluene under ultrasonic. As expected, the increase in latex content from 0.5, 1.0, 1.5 to 2.0 phr in porous epoxy produced the higher porosities as well as lower di...

To investigate the interlocking capability of porous epoxy microparticles (PEM) with elastomers, composites of PEM and ENR/NR were prepared on a two-roll mill. A proprietary method was used to produce the PEM, which have multiple microholes in their surfaces. By establishing an interlocking mechanism with the elastomer, the PEM have potential for u...

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 mat...

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 trappe...

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 typ...

Interlocking of polystyrene (PS) and porous hollow epoxy (PHE) was prepared by melt blend using Haake internal mixer. This novel porous hollow epoxy (PHE) was produced by water-based method and having multiple micro holes on the surface which has promising potential to be used as advanced reinforcing fillers through interlocking mechanism. The adva...