synthesis and characterization of polysiloxane
TRANSCRIPT
SYNTHESIS AND CHARACTERIZATION OF POLYSILOXANE COMPOUND AS
PRECURSOR OF SILICON DIOXIDE
SHEHU ISAH DANLAMI
A Thesis Submitted in
Fulfillment of the Requirements for the Award of the
Degree of Master of Science
Faculty of Science, Technology and Human Development
Universiti Tun Hussein Onn Malaysia
JANUARY, 2 0 1 5
ABSTRACT
Polymethylvinylsiloxane . (PMVS) was successfully synthesized by
prehydrolysislcondensation of methylvinydichlorosilane (MVDCS) and
dimethyldichlorosilane (DMDCS) followed by catalyzed equilibrium copolymerization
with sulphuric acid (H2S04) and dibutyltin dilaurate (DBTDL). Then PMVS was photo-
chemically converted to silicon dioxide films by UVIOzone exposure at room
temperature in the presence of atmospheric oxygen. All procedures in the experiment
were performed under ambient condition. The PMVS samples were characterized by
Fourier Transform Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance (13c and
2 9 ~ i NMR), thermal properties by Differential Scanning Calorimetry (DSC) and
Thermogravimetric analysis (TGA). The results obtained from DSC were 7.5 "C and 33 o C indicating that the polymethylviny'lsiloxane samples have low glass transition
temperature (T,) while TGA result showed low thermal decomposition temperatures at
50 OC and 110 "C with low residue yields as a result of oxidation or degradation of
methyllvinyl groups. The thin film was then characterized by FESEM and XRD for its
surface morphology characteristic and by ATR-FTER spectrometry for its molecular
change investigation. It was observed that SiOz film was significantly changed at 30
minutes of UVIozone exposure while increased in the time of exposure made the film
surface smoother which enhanced its chemical properties. ATR-FTIR spectra of
wavelength around 960 cm-', 1408 cm-I and 1598 cm-' correspond to vinyl group totally
disappeared under the UVIozone exposure whereas those at around 791 -795 cm-', 1258-
1260 cm", and 2962-2963 cm-' which correspond to methyl group have not been
significantly changed. From the XRD, SiOz film was found to be amorphous in nature
while from UV-Visible, the unmodified PVMS absorbed UV radiation at 230 nm and
upon increasing the UVIozone exposure time, the peak extends to a wavelength of 300
nrn.
ABSTRAK
Polimetilvinilsiloksana (PMVS) telah berjaya disintesis melalui pra-
hidrolisis/pemeluwapan metilvinildiklorosilana (MVDCS) dan dimetildiklorosilana
(DMDCS), diikuti oleh pengkopolimeran seimbang bermangkin dengan asid sulfurik
(H2S04) dan dibutiltimahdi'laurat (DBTDL). Kemudian, PMVS ditukarkan kepada filem
silikon dioksida menenlsi kaedah pendedahan fotokimia UV/ozon pada suhu bilik
dengan kehadiran oksigen dari atmosfera. Kesemua prosedur dalam eksperimen ini
dilakultan di bawah keadaan ambien. Sampel PMVS dicirikan dengan menggunakan
spektroskopi inframerah transisi fourier (FTIR), resonan rnagnetik nuklear (NMR 13c dan 2 9 ~ i ) , sifat-sifat terma dikaji menggunakan kalorimetri pengimbas pembezaan (DSC)
dan analisis termogravimetrik (TGA). Keputusan yang diperolehi daripada DSC adalah
7.5 OC dan 33 OC masing-masing, menunjukkan bahawa sampel-sampel PMVS memiliki
suhu peralihan kaca (T,) yang rendah, manakala keputusan TGA menunjukkan suhu
penguraian haba rendah, iaitu pada 50 "C dan 110 OC, serta menghasilkan sisa yang /'
sedikit akibat daripada proses pengoksidaan atau penurunan kumpulan vinil/metil.
Kemudian, filem nipis ini dicirikan menggunakan FESEM dan XRD untuk mengkaji
morfologi permukaannya dan spektrometri ATR-FTIR untuk kajian pelrubahan pada
molekulnya. Perbezaan morfologi permukaan filem nipis ini dapat diamati dengan jelas
apabila berada di bawah pendedahan UV/ozon selama 30 minit dan perlanjutan masa
pendedahan membuatkan perrnukaan kepingan menjadi lebih licin dan meningkatkan
sifat-sifat kimia. Puncak spektra ATR-FTIR yang berada pada nombor gelombang antara
960 cm-', 1408 cm-' dan 1598 cm-' yang merujuk kepada kumpulan vinil didapati
menghilang apabila didedahkan kepada UV/ozon manakala puncak spektra pada nombor
gelombang 791-795 cm-', 1258-1260 cm-' dan 2962-2963 cm-' yang merujuk kepada
kumpulan metil pula tidak menunjukkan perubahan ketara. Keputusan XRD
menunjukkan filem Si02 bersifat amorfbs secara semulajadi, manakala melalui W-
nampak PMVS didapati tidak terurai menyerap gelombang UV pada panjang gelombang
230 nm, dan apabila masa pendedahan UV/ozon dilanjutkan, puncak berlanjut ke
panjang gelombang berkadar 300 nm.
REFERENCES
Ackemann, H., Mania, D. J., Kirkpatrick, R. L., & Coffey, M. (20 13). US. Patent No.
8,4 70,949. Washington, DC: U.S. Patent and Trademark Office.
Agirre, I., Arias, P. L., Castricum, H. L., Creatore, M., ten Elshof, J. E., Paradis, G. G. &
Vente, J. F. (2014). Hybrid organosilica membranes and processes: Status and
outlook. Separation and Pur$cation Technology, 121, pp. 2-12.
Ahmad Z. & Mark J. E. (1998). Biomimetic materials: Recent developments in organic-
inorganic hybrids. Materials Science and Engineering. C 6. pp 183-196.
Anagnostopoulos, T., Eliades, G., & Palaghias, G. (1993). Composition, reactivity and
surface interactions of three dental silane primers. Dental Materials. 9(3), pp.
Andrianov, K. A,, Haiduc, I., & Khananashvili, L. M. (1963). Inorganic cyclic silicon- /
containing compounds and their organic derivatives. Russian Chemical Reviews.
32(5), pp. 243-268.
Auner, N. & Weis, J., (2005): Organosilicon Chemistry VI-From Molecules to
Materials Eds.; Wiley-VCH: Weinheim,
Auner, N., & Weis, J., (2008). Organosilicon Chemistry 111: From Molecules to
Materials. John Wiley & Sons.
Baradie, B., Lai, P. H., & Shoichet, M. S. (2005). Synthesis and characterization of
novel polysiloxane-grafted fluoropolyrners. Canadian Journal of Chemistry.
83(6-7), pp. 553-558.
Barnes, K. A., Tascarella, D. S., Julian, D. J., & Liles, D. T. (2013). U.S. Patent No.
8,580,862. Washington, DC: U.S. Patent and Trademark Office.
Bauer, J., Hiising, N., & Kickelbick, G. (2004). Tunable block copolymers based on a
polysiloxane backbone by anionic ring-opening polymerization. Journal of
Polymer Science Part A: Polymer Chemistry. 42(16), pp. 3975-3985.