Coating of polymethylmethacrylate with transparent SiO2thin films by a sol-gel method

✍ Scribed by R. Mizutani; Y. Oono; J. Matsuoka; H. Nasu; K. Kamiya

• Publisher: Springer
• Year: 1994
• Tongue: English
• Weight: 858 KB
• Volume: 29
• Category: Article
• ISSN: 0022-2461
• DOI: 10.1007/bf00349978

✦ Synopsis

In order to improve the surface characteristics of polymethylmethacrylate (PMMA), oxide thinfilm coatings were applied using the sol-gel dip-coating technique. The Si(OC2Hs) 4 (TEOS), CH3Si(OC2Hs) 3 (MTES) or Ti(O-i-C3H7) 4 (TIP) was used as a starting material for SiO2 or TiO2 coating. The hardness of the alkoxy-derived oxide-coated PMMA was increased from 200 MPa for non-coated PMMA with increasing film thickness. By optimizing the heating conditions and the hydrolysis conditions, and by repeating the dip-coating/heating processes, a hardness as high as 325 MPa was achieved in the PMMA triply coated with the TEOSderived SiO= film using the withdrawal velocity of 0.30 mms-1 and heat treatment at 80~ The increase in hardness with the thickness of coating film was saturated before reaching that of bulk silica-dried gel (ca. 500 MPa), which may be due to the increased porous nature of the thick films.