Asst.Prof.Dr. Sirilux Poompradub
ผู้ช่วยศาสตราจารย์ ดร. ศิริลักษณ์ พุ่มประดับ

 

 

 

 
 
B. Sc. (Chem.), Chulalongkorn University, Thailand
M. Sc. (Chem.), Chulalongkorn University, Thailand
D. Eng. (Poly. Chem.), Kyoto University, Japan
 
Office hour :
 

1. Reinforcement of natural rubber by nanofiller
2. In situ silica generated into natural rubber matrix by the sol-gel process
3. Strain-induced crystallization in natural and synthetic rubbers

Two phenomena, which can explain the reinforcement effect in rubber vulcanizates, are the addition of reinforcing filler and the strain-induced crystallization. Rubber composites are physical mixtures of rubber (as the matrix) and reinforcing filler (as the dispersed phase) that serves to improve some mechanical property such as modulus, tensile strength or abrasion resistance. Fillers may be organic (e.g., carbon black) or inorganic (e.g., silica or calcium carbonate) compounds.
Crystallization is of great importance with regard to the mechanical properties of elastomers since the generated crystallites are thought to provide the reinforcement in the materials. Some elastomeric networks show a large and rather abrupt increase in the modulus at high elongation. This increase is very important since it corresponds to a significant toughening of the elastomer. It had been widely attributed to either the “limited extensibility” of network chains or to strain-induced crystallization. However, many of the synthetic rubbers, particularly those formed by the random co-polymerization of two different monomer units, such as SBR and NBR, do not have a regular sequence of chain atoms and hence are incapable of forming a crystal lattice. Such rubbers, after vulcanization, generally have much lower strength than NR vulcanizates, though from the practical standpoint this difference can be largely overcome by suitable compounding techniques, e.g. by the incorporation of reinforcing filler.
Also, silica generated in situ, the new composite material, is the most interesting nanofiller to study the effect of reinforcement. It is produced in the rubbery matrix by the sol-gel reaction. A typical reaction is base-hydrolysis and condensation reactions of tetraethoxysilane (TEOS) as a precursor of silica. The mechanism of sol-gel reaction is

This reaction is concurrent and can be reversible depending on the reaction conditions such as pH, concentration, kind of catalysts, and temperature. This technique can produce the silica particles dispersed homogeneously in rubbery matrix both before and after curing.


T. Tuntulani, S. Poompradub, P. Thavornyutikarn, N. Jaiboon, V. Ruangpornvisuti, N. Chaichit, Z. Asfari and J. Vicens, “Aza crown ether calix[4]arenes containing cation and anion binding sites: effects of metal ions towards anion binding ability” Tetrahedron Lett., 42, 5541-5544 (2001).

T. Tuntulani, P. Thavornyutikarn, S. Poompradub, N. Jaiboon, V. Ruangpornvisuti, N. Chaichit, Z. Asfari and J. Vicens, “Synthesis of tripodal aza crown ether calix[4]arenes and their supramolecular chemistry with transition-, alkali metal ions and anions” Tetrahedron, 58, 10277-10285 (2002).

M. Tosaka, S. Murakami, S. Poompradub, S. Kohjiya, Y. Ikeda, S. Toki, I. Sics and B. S. Hsiao, “Orientation and crystallization of natural rubber network as revealed by WAXD using synchrotron radiation” Macromolecules, 37 (9), 3299-3309 (2004).

S. Poompradub, M. Tosaka, S. Kohjiya, Y. Ikeda, S. Toki, I. Sics and B. S. Hsiao, “Lattice deformation of strain-induced crystallites in carbon-filled natural rubber” Chem. Lett., 33 (3), 220-221 (2004).

M. Tosaka, S. Kohjiya, S. Murakami, S. Poompradub, Y. Ikeda, S. Toki, I. Sics and B. S. Hsiao, “Effect of network-chain length on strain-induced crystallization of NR and IR vulcanizates” Rubber Chem. Technol., 77 (4), 711-723 (2004).

S. Toki, I. Sics, B. S. Hsiao, S. Murakami, M. Tosaka, S. Poompradub, S. Kohjiya and Y. Ikeda, “Structural developments in synthetic rubbers during uniaxial deformation by in situ synchrotron X-ray diffraction” J. Polym. Sci.: Part B: Polym. Phys., 42, 956-964 (2004).

S. Toki, I. Sics, S. Ran, L. Liu, B. S. Hsiao, S. Murakami, M. Tosaka, S. Kohjiya, S. Poompradub, Y. Ikeda and A. H. Tsou, “Strain-induced molecular orientation and crystallization in natural and synthetic rubbers under uniaxial deformation by in-situ synchrotron X-ray study” Rubber Chem. Technol., 77 (2), 317-335 (2004).

S. Poompradub, M. Tosaka, S. Kohjiya, Y. Ikeda, S. Toki, I. Sics and B. S. Hsiao, “Mechanism of strain-induced crystallization in filled and unfilled natural rubber vulcanizates” J. Appl. Phys. 97, 103529/1-103529/9 (2005).

S. Poompradub, S. Kohjiya and Y. Ikeda, “Natural rubber/in situ silica nano-composite of a high silica content” Chem. Lett. 34, 672-673 (2005).

S. Toki, I. Sics, B. S. Hsio, M. Tosaka, S. Poompradub, Y. Ikeda and S. Kohjiya, “Probing the nature of strain-induced crystallization of polyisoprene rubber by combined thermomechanical and in situ X-ray diffraction techniques” Macromolecules, 38 (16), 7064-7073 (2005).

S. Poompradub, M. Tosaka, S. Kohjiya, Y. Ikeda, S. Toki, I. Sics and B. S. Hsiao, ″Effect of nanofillers on strain-induced crystallization and mechanical properties of natural rubber″ 51th Rheology of Elastomer conference, Nara, Japan, September 17-19, 2003 (Poster section).

S. Poompradub, S. Kohjiya, M. Tosaka, Y. Ikeda, S. Toki, I. Sics and B. S. Hsiao, ″Effect of fillers on strain-induced crystallization of natural rubber″, 52th Polymer conference, Yamaguchi, Japan, September 24-26, 2003 (Poster section).

S. Poompradub, M. Tosaka, S. Kohjiya, Y. Ikeda, S. Toki, I. Sics and B. S. Hsiao, ″Effect of nanofillers on strain-induced crystallization and mechanical properties of natural rubber″ 8th Pacific Polymer Conference (PPC8), November 24-27, 2003, Queen Sirikit National Convention Center, Bangkok, Thailand (Oral presentation).

S. Poompradub, M. Tosaka, S. Kohjiya, Y. Ikeda, S. Toki, I. Sics and B. S. Hsiao, ″Effect of nanofillers on strain-induced crystallization and mechanical properties of natural rubber″ 16th Elastomer Symposium, Tokyo, Japan, December 4-5, 2003 (Oral presentation).

S. Poompradub, M. Tosaka, S. Kohjiya, Y. Ikeda, S. Toki, I. Sics and B. S. Hsiao, ″Smart in situ nanocomposite: Strain-induced crystallization in carbon black filled natural rubber″ 40th IUPAC International Symposium on Macromolecules, Macro 2004, World Polymer Congress, July 4-9, 2004, Paris, France (Oral presentation).

S. Poompradub, M. Tosaka, S. Kohjiya, Y. Ikeda, S. Toki, I. Sics and B. S. Hsiao, ″Strain-induced crystallization in filled natural rubber vulcanizates″ 17th Elastomer Symposium, Kobe, Japan, December 2-3, 2004 (Oral presentation).

S. Poompradub, M. Tosaka, S. Kohjiya, Y. Ikeda, S. Toki, I. Sics and B. S. Hsiao, "Effect of carbon black loading on natural rubber: Strain induced crystallization and reinforcement″ The 3rd KIPS-NIST Joint Symposium on Polymer Science, May 19-20, 2005, Katsura Hall, B-Cluster, Graduate School of Engineering, Kyoto University, Kyoto, Japan (Poster presentation).

 

 

Faculty member

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Head of Department
Full-time Faculties

Prof.Dr.
Pattarapan Prasassarakich

Assoc.Prof.Dr.
Lursuang Mekasut
Assoc.Prof.Dr.
Pornpote Piumsomboon
Assoc.Prof.Dr.
Somkiat Ngamprasertsith
Assoc.Prof.Dr.
Khantong Soontarapa

Assoc.Prof.Dr.
Kejvalee Pruksathorn

Assoc.Prof.Dr.
Mali Hunsom
Assoc.Prof.Dr.
Nattaya Pongstabodee
Asst.Prof.Dr.
Suchaya Nitivattananon
Asst.Prof.Dr.
Prapan Kuchonthara
Asst.Prof.Dr.
Prasert Reub-roycharoen
Asst.Prof.Dr.
Chawalit Ngamcharussrivichai
Asst.Prof.Dr.
Napida Hinchiranan
Asst.Prof.Dr.
Sirilux Pompradub
Dr.
Nisit Tantavichet
Dr.
Kunakorn Poochinda

Dr.
Benjapon Chalermsinsuwan
Nathapol Pintuyothin
Emeritus Professors
Prof.Dr.
Somsak Damronglerd
Assoc.Prof.
Kunchana Bunyakiat
Asst.Prof.
Samran Tungtong
Dr.
Pienpak Tasakorn