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School of Polymer Engineering, Institute of Engineering, Suranaree University of Technology, NaKhonRatchasima 30000, Thailand; e-mail address: [email protected]
Abstract This study was to investigate pressure oscillation in capillary flow of the three metallocene
catalyzed ethylene/1-octene copolymers which have homogeneous comonomer distribution and narrow molecular weight distribution due to metallocene catalyst technology. The copolymers of the same melt flow index of 1 (g/10 min) with the 1-octene content of 45, 30, and 20 wt% were used. It was found that at 160°C, the pressure oscillation was not observed for all three copolymers. The copolymers with 20 and 30 wt% showed the pressure oscillation with alternating smooth and sharkskin roughened extrudates. The width of shear rate at which the pressure oscillates of these two copolymers was independent of the comonomer content. This pressure oscillation was not observed for the copolymer with 45 wt% at any temperature studied.
ตีพิมพใน : The 29th Congress on Science and Technology of Thailand, KhonKaen, Thailand, Oct.20-22, (2003) p.210.
FLOW INSTABILITY OF HIGH DENSITY POLYETHYLENE/LOW DENSITY POLYETHYLENE BLENDS
จันทิมา ดีประเสริฐกุล* และ สมาน ใยแสง Chantima Deeprasertkul*, Saman Yaisang
School of Polymer Engineering, Institute of Engineering, Suranaree University of Technology, NaKhonRatchasima 30000, Thailand; e-mail address: [email protected]
Abstract Capillary flow instability of two HDPE/LDPE blend series using the same LDPE with MI
7.0 (g/10 min), one with HDPE of melt flow index (MI) 0.03 (g/10min) and another with HDPE with MI 18 (g/10 min) were investigated. Flow instabilities such as sharkskin-like extrudates and gross distorted extrudates were observed in HDPE of MI = 0.03 while only smooth extrudates were obtained in HDPE of MI = 18. LDPE also showed the gross distorted extrudates. It was found that processing range of HDPE and LDPE can be improved by blending with lower viscosity counterpart i.e. the sharkskin appearance in HDPE and the gross distortion in LDPE were suppressed/delayed to the higher shear rate applied.
ตีพิมพใน: The 29th Congress on Science and Technology of Thailand, KhonKaen, Thailand, Oct.20-22, (2003) p.215.
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ผลกระทบของปริมาณของแข็งในน้ํายางตอความหนดืของน้ํายางธรรมชาติเขมขน EFFECT OF TOTAL SOLIDS CONTENT ON THE VISCOSITY OF NATURAL RUBBER
1School of Polymer Engineering, Institute of Engineering, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand, 2Department of Chemistry, Faculty of Science, Khon Kaen
Abstract The present work is focused on the effect of total solids content (TSC) in natural rubber latex (NRL) on the viscosity (η). Concentrated NRL from two agricultural regions were investigated. At shear rates studied, η of both NRL samples increased with the increase of TSC. The η significantly increased when the TSC is higher than 60-62 % (by wt.). At any shear rate, NRL from Udornthani showed the higher η than NRL from Suratthani. ตีพิมพใน: The 4th National Symposium on Graduate Research, Lotus Hotel Pang Suan Laew, Chang Mai: Chiangmai University.
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การประยุกตใชสมการของ MOONEY และ KRIEGER-DOUGHERTY กับน้ํายางธรรมชาต ิAPPLICABILITY OF MOONEY AND KRIEGER-DOUGHERTY EQUATIONS TO
1School of Polymer Engineering, Institute of Engineering, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand; *e-mail address: jatuporn_sridee@ya- hoo.com 2Department
of Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand
Abstract Two mathematical equations, namely Mooney and Krieger-Dougherty, are commonly used to rheology of colloid systems with rigid or slightly deformable particles. In this study, we applied these two equations to natural rubber latex (NRL) concentrates. Under conditions studied, natural rubber particles are deformable. Based on particles size analysis, it was found that particle size distribution of NRL is polydisperse, with the particle size distribution index (Pd) ranging from 1.09-1.14. By fitting the viscosity with those equations, it was found that correlation coefficients (R2) are greater than 0.99. It means that both equations can be used in polydisperse and deformable system such as in NRL concentrates. With the higher R2 obtained, it suggests that Krieger-Dougherty equation is more suitable to NRL than Mooney. ตีพิมพใน : The 31st Congress on Science and Technology of Thailand, Nakhon Ratchasima,
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Thailand, Oct.18-20, (2005) p.228.
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วัสดุพอลิเมอรจากเทคนิคพอลิเมอไรเซชันแบบแรดิคอลชนิดมีการยายอะตอม POLYMERIC MATERIALS BY ATOM TRANSFER RADICAL
Abstract Atom transfer radical polymerization (ATRP) is one of the most effective methods to
polymerize a variety of monomers in a living fashion, yielding polymers with predetermined molecular weight and narrow molecular weight distributions and with well-defined structure. Moreover, because of its radical nature, ATRP is tolerant to many functionalities in monomers leading to polymer with functionalities along the chains. Therefore, ATRP technique is recently applied to develop various polymers, which is suitable for different applications. This review article describes the fundamental of ATRP and provides examples of polymeric materials synthesized successfully by ATRP.
บทคัดยอ เทคนิคพอลิเมอไรเซชันแบบแรดิคอลชนิดมีการยายอะตอม (atom transfer radical
Abstract Addition of Dyhard® 100 and Dyhard® 100s having average size gain of less than 40 µm and 10 µm, respectively, into prepreg hardener did not have the significant influenct of the impact strength of the cured prepreg. Contradictory, the larger particle size had the pronounce effect on the elevation of the HDT. By using Dyhard® 100 and Dyhard® 100s at the weight ratio of 10% to 30%, it maximized the tensile properties of the final product. On the other hand, at % weight ratio of 30% to 10% it enhanced the toughness, by mean of flexural properties. The prepreg hardener using three main classes of amine curing agent, they had quite visibly outcome in the possessions of the composite. The HDT of cured prepreg using cycloaliphatic, IPDA and aliphatic amines, TETA, showed the maximum figure. Hardener added with aromatic amine, Ancamine® 2165, exhibited the outstanding tensile properties. It was also improved the toughness, by mean of flexural strength, of the materials. ตีพิมพใน: การประชุมงานวชิาการวิทยาศาสตรและเทคโนโลยีแหงประเทศไทย คร้ังที่ 31 หนา 229.
Abstract The Rossells fibers were prepared by boiling in a methanol/benzene mixture; boiling in the
mixed solvent and then alkalization in sodium hydroxide solution; and treating with silane coupling
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agents after boiling in the mixed solvent and then alkalization. Vinyltriethoxysilane (VS) and γ-aminopropytrimethoxysilane (APS) were used as coupling agents. The thermal properties and surface characteristics of nonpretreated, solvent-boiled, pretreated, and silane-treated fibers were investigated by thermal gravimetric analyzer (TGA) and scanning electron microscope (SEM), respectively. The fiber diameter was determined by optical microscope (OM). It was found that boiling method removed wax or other low molecular weight components from the fibers. If pretreatment was performed, boiling method followed by alkalization, hemicellulose was further removed from the fibers. The fiber diameters were decreased after boiling method and pretreatment. The thermal properties and the diameter of silane-treated fibers did not significantly change, comparing to those of the pretreated fibers. ตีพิมพใน: The 31st Congress on Science and Technology of Thailand, Nakhon Ratchsima, Thailand, 2005, p. 241.
Two pretreatment methods (boiling method and soxhlet extraction) were employed to pretreated jute fibers with methanol-benzene 1:1 solvent mixture at various times. Thermal analysis was performed by Thermal Gravimetric Analysis (TGA) and the surface analysis was done by Scanning Electron Microscope (SEM). TGA curves shows that both of the pretreatment methods effectively remove wax or other low molecular weight components of the fibers. SEM results show that the boiling method takes a shorter optimum time to clean the fiber.
ตีพิมพใน: The 30st Congress on Science and Technology of Thailand, Nakhon Ratchsima, Thailand, 2004, p.175. 161
Abstract The shear-induced crystallization of injection molded vetiver grass-polypropylene
composites was investigated. A distinct skin layer due to the shear-induced crystallization of the samples was observed. The effect of processing conditions on the normalized thickness of skin layer was studied. It was found that the normalized thickness of skin layer decreased with an increase in injection speed and mold temperature. However, the screw speed and holding pressure slightly affected the normalized thickness of skin layer. Compared to polypropylene, vetiver grass-polypropylene composites showed lower normalized thickness of skin layer. ตีพิมพใน: The 31st Congress on Science and Technology of Thailand, Nakhon Ratchasima, Thailand, 2005, p. 221. 162
EFFECT OF MOLECULAR WEIGHT AND COMONOMER CONTENT ON CAPILLARY FLOW INSTABILITIES OF METALLOCENE ETHYLENE/1-OCTENE COPOLYMERS
Chantima Deeprasertkul and Montaree Jakkujan
School of Polymer Engineering, Institute of Engineering, Suranaree University of Technology, NaKhonRatchasima 30000, Thailand; e-mail address: [email protected]
Abstract
Metallocene-catalyzed ethylene/1-octene copolymers were studied using controlled-speed capillary rheometer in order to identify the onset of flow instabilities. Molecular weight and % comonomer content were varied. Two series of the copolymers were used: (1) copolymers having the same comonomer content with different melt flow indices and (2) copolymers having the same melt flow index with different comonomer contents. It was found that the onset rate of sharkskin and the onset rate of gross distortion increase with increasing of the melt flow index. Severity of sharkskin increases with the melt flow index and the shear rate applied. Both onset rates of sharkskin and gross distortion were found to decrease and level off with increasing of the 1-octene comonomer content. ตีพิมพใน: The 8th Pacific Polymer Conference, Bangkok, Thailand, Nov. 25-27, (2003) p.133.
SHORT ROSSELLS FIBER/POLYPROPYLENE COMPOSITES: EFFECT OF COMPATIBILIZER ON MECHANICAL AND RHEOLOGICAL PROPERTIES, AND
HEAT DISTORTION TEMPERATURE
Kasama Jarukumjorn*, Wimonlak Sutapun, Yupaporn Ruksakulpiwat, Jongrak Kluengsamrong School of Polymer Engineering, Institute of Engineering, Suranaree University of Technology,
Abstract The effect of maleic anhydride grafted polypropylene (PP-g-MA) as a compatibilizer on the mechanical and rheological properties, and heat distortion temperature (HDT) of short rossells/PP composites was evaluated. The composites were prepared in an internal mixer. The rossells fiber loading was 20 wt% and the compatibilizer contents were 1-10 phr. Tensile strength and unnotched impact strength of the composites increased with increasing the compatibilizer content. The compatibilizer improved the compatibility between the fiber and polymeric matrix. ตีพิมพใน: บทคัดยอการประชุมวิชาการวิทยาศาสตรและเทคโนโลยีแหงประเทศไทย คร้ังที่ 31 หนา 227. 164
EFFECT OF COMPATIBILIZER ON MECHANICAL, MORPHOLOGICAL, AND RHEOLOGICAL PROPERTIES OF RECYCLED HIGH DENSITY POLYETHYLENE
(HDPE)/POLYETHYLENE TEREPHTHALATE (PET) BLENDS
Kasama Jarukumjorn*, Sukunya Chareunkvun, Wecharit Sucharit, and Saman Yaisang School of Polymer Engineering, Institute of Engineering, Suranaree University of Technology,
Abstract Effect of maleic anhydride grafted polyethylene (PE-g-MA) as a compatibilizer on the mechanical, morphological, and rheological properties of recycled HDPE/PET blends was investigated. The blends were prepared in a twin screw extruder. Tensile and impact properties improved with addition of the compatibilizer. The compatibilized blends had the smaller size of dispersed phase compared to uncompatibilized blends. The influence of compatibilizer content to compatibilize the blends was also studied. ตีพิมพใน: บทคัดยอการประชุมวิชาการวิทยาศาสตรและเทคโนโลยีแหงประเทศไทย คร้ังที่ 31 หนา 220.
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DEVELOPMENT OF FIRE RESISTANT WOOD-SUBSTITUTED COMPOSITES FROM POLYBENZOXAZINE ALLOY
Natcha Kampangsaeree1, Nitinat Suppakarn2, and Sarawut Rimdusit1*
1 Polymer Engineering Laboratory and Center of Excellence on Particle Technology & Material Processing, Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn
University,Bangkok 10330, Thailand 2 School of Polymer Engineering, Institute of Engineering, Suranaree University of Technology,
Abstract Enhanced fire resistant wood-substituted composites from polymer alloys between benzoxazine/phenolic novolac resins and hevea brasiliensis woodflour filler are developed. The objectives of this work are to investigate the effects of polymer alloy composition on the wood composite’s flammability and thermal properties. The experimental results reveal that the value of a limiting oxygen index is raised from 25.2 in polybenzoxazine wood (at 50wt% woodflour filler) to about 27 in the benzoxazine/phenolic novolac polymer alloy mass ratio of 70/30 (BP73), up to 28.1 in the polymer alloy mass ratio of 30/70 (BP37) comparing at the same woodflour content of 50wt%. The rate of burning is 17.7 mm/min for the same polybenzoxazine wood while that of polymer alloy mass ratio of 70/30 (BP73) and beyond that using equal woodflour content of 50wt% exhibited the self-extinguishable nature. Finally, the limiting oxygen index is found to decrease while the rate of burning is increased with increasing wood content. ตีพิมพใน: The 3rd Thailand Material Science and Technology Conference, Bangkok, Thailand, 2004, p.161.
1 School of Polymer Engineering, 2 School of Ceramic Engineering, Suranaree University of Technology, Nakhonratchasima 30000, Thailand. *E-mail address: [email protected]
Abstract Cattle bone based hydroxyapatite (HA) particles of five different sizes (<45-150 mm) were prepared and used to manufacture HA-polypropylene (PP) composites containing a 40% (w/w) of HA content. It was found that HA of different particle sizes does not significantly change tensile strength, tensile modulus and flexural modulus of the HA-PP composites. However, composites of smaller HA sizes show slightly higher elongation at break. The composites in the wet state with a particle size less than 45 mm have the highest impact strength in comparison with those in dry state. ตีพิมพใน: The 31th Congress on Science and Technology of Thailand, Nakhon Ratchasima, Thailand, 2005, p.242.
Abstract Rossells-epoxy composites with various fiber contents were fabricated using nonwoven fibrous sheets of rossells fibers; untreated fibers and treated fibers (alkalined fibers). The treated fibers seem to increase the stiffness of the epoxy composites as seen from an increase of Young’s modulus with increasing treated fiber content. However, SEM micrographs from fracture surfaces of epoxy composites, from both untreated and treated fibers, suggest that no chemical bond exists at fiber-matrix interface. ตีพิมพใน: The 31 st Congress on Science and Technology of Thailand, Nakhon Ratchasima, Thailand, 2005, p.237.
Abstract Hydroxyapatite (HA)-PP composites containing various HA contents were produced using
HA powders prepared from cattle bones. An increase in HA content leads to increases in Young’s modulus, flexural modulus, and tensile strength of HA-PP composites with a simultaneous reduction in elongation at break. Increasing HA content results in decreasing impact strength of the composites of both dry and wet states. However, the composites in the wet state with a HA content beyond 40 % have higher impact strength in comparison with those in dry state with the same HA content. Published in: The 31st Congress on Science and Technology of Thailand, Nakhon Ratchasima, Thailand, 2005, p. 242.
Abstract Unsaturated polyester resin rossells fibers composites, non-woven fibrous sheet, were prepared using alkali and non-alkali treatment fibers. The amount of fibers was varied between 3 - 12 % by weight. Tensile properties of the composites were evaluated. Tensile moduli of the composites with alkali treatment fibers were higher than that of unsaturated polyester resin and were also higher than the moduli of composites with non-alkali treatment fibers. The composites, with all level of fibers, possessed lower tensile strength than unsaturated polyester resin. However, the tensile strength of the composites with alkali and non-alkali treatment did not show significant difference and it tended to increase with increasing fiber loading. ตีพิมพใน: บทคัดยอการประชุมวิชาการวิทยาศาสตรและเทคโนโลยีแหงประเทศไทย คร้ังที่ 31 หนา 234-235.
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BANANA FIBRES: EXTRACTION AND POTENTIAL USE AS REINFORCEMENT FOR POLYPROPYLENE
Pranee Chumsamrong and Jongrak Kluengsamrong
School of Polymer Engineering, Institute of Engineering, Suranaree University of Technology, Nakornratchasima 30000
Abstract The objective of this work was to investigate fibre extraction from banana pseudo-stem and the potential use of these banana fibres as reinforcement for polypropylene (PP). A combination of chemical and mechanical methods was used for extraction of banana fibres. Thermal and tensile properties of the fibres were evaluated. The average tensile modulus and tensile strength of the banana fibres were 14.32 GPa and 384 MPa respectively. The composites were prepared by combining banana fibres and PP with 1-10 % weight content of fibres. Tensile moduli of the composites tended to increase with increasing amount of fibres. The composites, with all level of fibres, possessed higher tensile strength than PP matrix. However, when percent of fibres was increased, tensile strength decreased. Impact strength of the composites decreased with increasing amount of fibres. Optical microscopy photomicrographs of the composites with high fibre weight fractions showed some voids inside. The overall results revealed that banana fibres have potential use as reinforcing material for PP.
ตีพิมพใน: The 3rd Thailand Materials Science and Technology Conference Bangkok, p. 391 - 393.
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POLY (BUTYL ACRYLATE) GRAFTED NATURAL RUBBER LATEX: PREPARATION AND FILM FORMING PROPERTIES
School of Polymer Engineering, Suranaree University of Technology, Nakornratchasima, Thailand E-mail address: [email protected]
Abstract
Natural rubber latex grafted with poly (butyl acrylate) (PBA) was prepared by emulsion polymerization. Two types of initiator including redox system [cumene hydroperoxide (CHP)/tetraethylene pentamine(TEPA)] and thermolysis initiator (potassium persulfate) were used. At used condition, the latex was still stable. Two initiator systems gave high percentage conversion. 1H-NMR results showed that the latex prepared in this emulsion polymerization contained graft copolymer. Grafting reaction using two different initiator systems led to brittle film and the film was more brittle when redox initiator was used. Published in: The 31th Congress on science and technology Thailand, pp 233.
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CHARACTERIZATION OF CHEMICAL TREATED VETIVER GRASS
Usa Somnuk, Yupaporn Ruksakulpiwat*, Nitinat Suppakarn and Wimonlak Sutapun School of Polymer Engineering, Suranaree University of Technology,
Abstract In this study, vetiver grass was prepared as untreated and treated (solvent extraction and alkali treatment) grass. The thermal characteristics, functional groups analysis and surface morphology of untreated and treated vetiver grass was investigated using thermogravimetric analysis (TGA), diffuse reflectance infrared fourier transform (DRIFT) spectroscopy and scanning electron microscope (SEM). The results show that alkali treatment seems to be the most effective method to treat the vetiver grass.
ตีพิมพใน: The 3rd Thailand Material Science and Technology Conference, Bangkok, Thailand, 2004, p. 420.
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EFFECT OF PHOTO ACCELERATORS ON THE DEGRADATION OF POLYSTYRENE FOAM WASTE
Utai Meekum 1* and Reukrij Kenharaj2
Received: Dec 18,2003; Revised: Sept 2,2004; Accepted: Sept 3, 2004 1 School of Polymer Engineering, Institute of Engineering, Suranaree University of Technology,
Nakhon Ratchasima 3000, Thailand 2 Construction Technology Program, Faculty of Science and Technology Rajabhat University Udon
The Polystyrene (PS) foam has been widely used as food packaging and insulators. The former application has been commonly seen as take-away meal boxes. When it reaches the end-users, it would be discarded as municipal solid waste (WSWs). It would readily undergo photodegradation if it was disposed in the open-air dumping. It would take months to be degraded in the natural condition. In the present study, the degradation rate of the PS-foam in open-air dumping and in the artificial exposure, using Standard weatherometer, was investigated. Benzoyl peroxide and AIBN were used as photo accelerators. The concentration of these chemicals varied from 1 % to 3 % by weight. The decrease in the number average molecular weight of the samples, characterized by GPC technique, was monitored and used to calculate the reaction rate, By using the degradation rate mathematical modeling the order of reaction (b), rate constant ( )k ′ and the half-life ( )21/t of the photo reactions were obtained. The results showed that the b was increased with the increase of concentration of the accelerators. Likewise, the k′ decreased. However, by considering the ( )21/t it was found that the half life of photo reaction using peroxide as the accelerator slightly decreased when the concentration increased form 1 % to 3 %. Nevertheless, the value decreased significantly when the AIBN was employed. Published in: Suranaree J. Sci. Technol. 11:223-229.
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STUDY OF THE MOLECULAR STRAIN OF POLYMERIZABLE CYCLIC OLIGOCARBONATES USING THE SPECTROSCOPIC TECHNIQUES
Utai Meekum
School of Polymer Engineering, Institute of Engineering, Suranaree University of Technology
Received: Aug 4, 2004; Revised: May 9, 2005; Accepted: May 13, 2005
Abstract
Cyclic oligocarbonates, dimer, trimer and tetramer, were synthesized and purified into individual cyclic dimer, trimer and tetramer, respectively. The UV/Vis, IR and Raman spectroscopic techniques were used to study the molecular strain of those cyclics. The The UV/Vis data revealed that the due to the phenyl group was shifted from 250 nm for the dimer to 280 nm for the trimer and tetramer. The of the carbonyl group was also shifted from 305 to 316 nm. The extinction coefficient ratio at 254 and 280 nm, of the dimer was also differed from the others. The results indicated the molecular ring-strained of the dimer. IR and Raman spectroscopic data in the region of 3,700 – 2,400 cm
maxλ
maxλ
,/ 280254 εε
-1,2 ,200 – 1,000 cm-1 , and 1,100 – 400 cm-1 of C-H stretching, carbonate linkage and = C-H bending of the cyclic dimer that were obviously differed from the cyclic trimer and tetramer. The differences were believed to be arisen from the bond angle of the carbonate linkage and the intermolecular interaction of hydrogen on aromatic ring. The torsion angles of the aromatic ring on the isopropylidene group would be suspected as a prime contribution for the molecular strain of these cyclic species. Keywords: Cyclic oligocarbonates, spectroscopic techniques, molecular strain Published in : Suranaree J. Sci. Technol. 12(2):107-113.
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EXPERIMENTAL DESIGN FOR PREPRAG FORMULATION
Utai Meekum., W. Na-chai School of Polymer Engineering, Institute of Engineering,
Suranaree University of Technology
Abstract The preprag formulation comprised of the DGEBA epoxy based resin mixture and amines based hardener. The hardener was formulated from three components chemical group, Dicyandiamides, Urea catalysts and aliphatic and aromatic amines compound. The effect of epoxy ratio in mixture of the resin based, ratio of Dicyandiamides, B-stage hardener, amines composition and concentration of the catalyst on the tensile, flexural, impact, heat distortion temperature and B-stage cure of the preprag formulation were studied. For the given optimal formulation, the consequence of cure and post curing conditions on those properties were also reviewed. Published in : In International Conference and Exhibition W fibrous Materials –XXI Century Saint- Petersburg, Russia. May 23-28, 2005.
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POLYCARBONATE REINFORCED SHORT FIBERS COMPATIBILIZED WITH HIGHLY BRANCHED EPOXY SYSTEM
Utai Meekum, Onuma Charoensuk
School of Polymer Engineering, Suranaree University of Technology, Nakornratchasima, Thailand.
Abstract The PC reinforced with short glass(GF), Kevlar(KV) and carbon(CF) fiber at 15% by weight and compatibilized with highly branched epoxy/DDS system were prepared using the twin screw extruder. The HDT, impact, flexural and tensile properties were tested. The result revealed that PC/GF composite had superior properties than virgin PC and PC/epoxy blends. However, adding other fibers in the composites showed the inferior properties. The verdict of these results could be due to the volumetric overload of the polymer matrix. Published in: The 31th Congress on science and technology Thailand, pp 216.
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THERMAL, RHEOLOGICAL, MECHANICAL, AND MORPHOLOGICAL PROPERTIES OF VETIVER-POLYPROPYLENE COMPOSITES
Wandee Thuamthong, Yupaporn Ruksakulpiwat, Wimonlak Sutaphan, and Nitinat Suppakarn
School of Polymer Engineering, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand. [email protected]
Abstract
In this study, vetiver-polypropylene (PP) composites were studied. Vetiver grass prepared as vetiver leaves and vetiver fibers was used. The vetiver-PP composites were prepared at 5, 10, 20, and 30% of vetiver contents. The thermal properties of vetiver grass and vetiver-PP composites was studied. Vetiver fibers show higher decomposition temperature than vetiver leaves. Thermal resistance of vetiver-PP composites increases with increasing vetiver content. The viscosity of vetiver-PP composites increases with increasing vetiver content. The tensile strength, yield strength, Young’s modulus and impact strength were elucidated. The morphology of fracture surfaces obtained from scanning electron microscopy (SEM) shows poor adhesion between fibers and matrix.
ตีพิมพใน: The 8th Pacific Polymer Conference (PPC8), Bangkok, Thailand, November 21-23, 2003, p. 118.
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EFFECT OF VETIVER CONTENTS AND VETIVER LENGTHS ON MECHANICAL AND MORPHOLOGICAL PROPERTIES OF VETIVER-POLYPROPYLENE COMPOSITES
Wandee Thuamthong, Yupaporn Ruksakulpiwat*, Wimonlak Sutapun, and Nitinat Suppakarn
School of Polymer Engineering, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand.
Abstract In this study, the effect of vetiver lengths and vetiver contents on mechanical and morphological properties of vetiver grass-polypropylene (PP) composites were investigated. Vetiver grass (Vetiveria Zizanioides) with various lengths were prepared as sodium hydroxide (NaOH) treated vetiver leaves. The vetiver grass-PP composites were prepared by mixing PP and NaOH treated vetiver leaves at various ratios. The effects of vetiver contents and vetiver lengths on tensile strength, Young’s modulus, % elongation at break, and impact strength were studied. The tensile strength, % elongation at break, and impact strength of vetiver-PP composites decrease with increasing vetiver content while the Young’s modulus of the composites increases with increasing vetiver contents. The tensile strength increases with increasing vetiver length from 0.11 mm to 1.60 mm and then it remains unchanged. Vetiver length shows no effect on Young’s modulus. The impact strength and % elongation at break of vetiver-PP composites decreases with increasing vetiver lengths. The morphology of vetiver-PP composites were obtained from scanning electronmicroscopy (SEM). Published in : The 3nd Thailand Science and Technology Conference, Bangkok, Thailand, October 19-21, 2004, pp. 167.
Abstract Injection molding was used to prepare rossells-polypropylene (PP) composites. The effect of processing parameters on mechanical properties of injection molded specimens was studied. This included melting temperature, injection speed, screw speed, holding pressure and mold temperature. It was found that melt temperature and mold temperature affected the mechanical properties of the composites while the injection speed, the holding pressure and the screw speed showed no significant effect on the mechanical properties. ตีพิมพใน: การประชุมวิชาการวิทยาศาสตรและเทคโนโลยีแหงประเทศไทย คร้ังที่ 31 หนา 227.
Abstract From our previous study, it was found that vetiver grass fiber can be used as a reinforcing filler in polypropylene (PP) composites. Vetiver grass-PP composites exhibit higher tensile strength but lower impact strength than PP. This research has a purpose to improve the impact strength of vetiver grass-PP composite by using natural rubber as an impact modifier. The effect of natural rubber contents in the composites on mechanical properties was studied. Moreover, the effect of silane coupling agent on the mechanical properties of the composites was elucidated. It was shown that an increase in natural rubber contents led to an increase in the impact strength and % elongation and a decrease in tensile strength. Silane coupling agent was shown to improve the mechanical property of natural rubber-vetiver grass-PP composite
THE STUDY OF USING VETIVER GRASS AS A FILLER IN POLYPROPYLENE COMPOSITES
Y. Ruksakulpiwat, N. Suppakarn, W. Sutapun and W. Thomthong School of Polymer Engineering, Suranaree University of Technology,
111 University Avenue, Nakhon Ratchasima 30000, THAILAND
Abstract The vetiver-polypropylene (PP) composites were prepared at various ratios of vetiver contents. Vetiver grass was prepared as vetiver leaves and vetiver fiber. The effect of vetiver contents on thermal, rheologica, mechanical and morphological properties of the composites were studied. Vetiver grass was treated by chemical treatments and the effect of chemical treatments on the these properties was elucidated. Published in : ANTEC 2004/4641-1645, May 16-22 , 2004. 182
Abstract Polypropylene (PP) composites from various types of Thai natural fibers were prepared by injection molding. Natural fibers used in this study are rossells, sisal and vetiver grass. The effect of fiber contents on mechanical property of the composites was studied. Comparison of rheological and mechanical properties of the composites from various types of natural fibers was elucidated. When compared to PP, PP composites from rossells, sisal and vetiver grass exhibited higher tensile strength, yield stress and Young’s modulus but lower impact strength. Moreover, polypropylene composite from vetiver grass exhibits highest viscosity and tensile strength while polypropylene composite from rossells exhibits highest Young’s modulus and impact strength.
Abstract Thermoplastic elastomers (TPEs) preparing by dynamic vulcanization of natural rubber and
isotactic polypropylenes (i-PP) blends at various compositions were used in this study. Rheological properties and thermal properties of these TPEs were determined. Injection molded TPEs were prepared at various injection conditions including three injection speeds and three melt temperatures. The effects of melt temperature and injection speed on morphology and mechanical property of injection molded TPE were studied.
ตีพิมพใน: The 8th Pacific Polymer Conference (PPC8), Bangkok, Thailand, November 21-24,