Application and Performance Enhancement of PET Bottles by TiO2/SiO2 Nanopowders

• Main Authors: Pei-Song Chu, 朱北松
• Other Authors: Kuen-Song Lin
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/12204909747709659004

碩士 === 元智大學 === 化學工程與材料科學學系 === 95 === Recently, nanotechnology had been applied on polyethylene terephthalate (PET) synthesis processes. The SiO2 nanoparticles have good mechanics, acid-resisting, and heat-proof properties by their network structures. TiO2 nanoparticles also have excellent chemical stability, nontoxicity, and shadowing of the ultra-violet properties. Therefore, in this research, different ratio of TiO2 and SiO2 could reduce gas permeability, pressure-proof, and ultra-violet shadowing characteristics of PET bottles. Moreover, the physcochemical, crystal microstructures, and morphological properties of PET bottle chips were also determined by FE-SEM, XRPD, TEM, UV-Vis spectra, DSC/DMA, FTIR, and ICP-MS. The XRPD patterns showed that the TiO2 ratio increased as the enhanced P-25 peaks, in contrast the SiO2 ratio increased as the reductive P-25 peaks. The diameter of TiO2/SiO2 nanoparticles without lapping measured by FE-SEM were 50 nm, on the contrary, after lapping the nanoparticles size were decreased to 20-50 nm. Meanwhile the ratios of TiO2/SiO2 (2:8 ~ 8:2) dopped into PET made the ultra-violet shadowing property of PET reach the extent of other commercial beer bottles. In addition, the ultra-violet absorption wavelength was shifted toword 440 nm when compared to other beer bottle merchandises at doped ratio 5:5 TiO2/SiO2 into PET. After doping TiO2/SiO2 into PET showed the value of Tg, Tm or Tcc and modulus properties were significantly improved. The value of Tg or Tm was raised about 3 ~ 5℃ and the one of Tcc was raised about 14 ~ 21℃ as determined by DSC and DMA techniques. Moreover, the increase of Tg, Tm or Tcc value made the heat-proof of PET bottles meet the Pasteurizer standard procedure. The FTIR spectra showed that the peak of C=O (1700-1750 cm-1), COO (1304 cm-1) and C-H (730-770 cm-1) were shifted when dopping ratio increased. The FTIR spectra indicated that the TiO2/SiO2 nanocomposites had been linked up into PET microstructures. From the ICP-MS analyses, with doping TiO2/SiO2 nanoparticles made the leaching temperture of Sb(III) ions increased from 50 to 70℃ and lower the leaching concentration of Sb(III) ions in nanaocompositive PET bottles. Without doping SiO2 into the TiO2 for PET bottles, the coordination numbers (CN) of Ti atom and crystal structure were not changed. Ti EXAFS spectra also indicated that the CN and the bond distances were 3.96 ± 0.05 and 1.96 ± 0.01 Å respectively. After doping different ratios of TiO2/SiO2 (1:9 ~ 9:1) into PET bottless, it showed that the CN and bond distances were notably changed. Moreover, it could prove the TiO2 and SiO2 nanoparticles were reacted and formed into Ti-O-Si bonding eventually. After gas permeability test, with different doping ratios of TiO2/SiO2 nanoparticles into PET bottles showed that the minimum pressure drop ratio was 0.3%. In other words, it indicated that the TiO2/SiO2 nanocomposites had been linked up into PET microstructures strongly and well sealed off oxygen gases for the PET bottles. In addition, at the same temperature of injection molding process, with doping 0.3% TiO2/SiO2 nanoparticles into PET bottles, it made the degree of pellucidity or hand handle higher than that one of 5% and can meet the commercial standards of pellucidity and hand handle.