Cycloaliphatic Epoxide Based Sol-Gel Derived Materials
- PDF / 1,590,539 Bytes
- 7 Pages / 414.72 x 648 pts Page_size
- 65 Downloads / 183 Views
G. A. SIGEL, R.C DOMSZY, AND W. C. WELCH Innovation Center, Armstrong World Industries, P.O. Box 3511, Lancaster PA 17604 ABSTRACT
Scratch resistant transparent organically modified sol-gel materials typically utilize organics as acrylates, or pre-polymer silicon or carbon backbone material. The use of diepoxide monomers within a sol-gel matrix has yet to be described as a means of obtaining high performance coating materials. This paper describes the preparation and characterization of UV curable inorganic-organic hybrid glass materials based on the incorporation of cycloaliphatic diepoxide monomers into a sol-gel composition of TEOS and the epoxide silane coupling agent glycidoxypropyltrimethoxysilane. We report aging and humidity studies along with processing conditions that affect the silicate distribution and cationic cure of the diepoxide resin based on solution and solid state NMR experiments. Mechanical analysis of thin films prepared by varying processing conditions and length of the diepoxide backbone are also discussed.
INTRODUCTION
There has been a great deal of interest focused on the development of Organically-Modified Sol-Gel Glass materials (ORSGG) for use as protective barriers and monoliths."'3 This primarily stems from the attractive processing advantages these materials offer over that of conventional glass ceramics. The 'glass-like' properties combined with the flexibility of organic moiety allows these material to be used in a number of low temperature applications. A few commercial applications of ORSGG coatings include abrasive resistant coatings for eye glass lenses, plastic windows, and beverage bottles." Several efforts have focused on modifying the silica network by use of R substituents on silicon or
0'--loS-(C H2)3---O 00
use of organic monomers that form interpenetrating chains within the TEOS-TMOS sol-gel derived networks. True hybrid systems that link the organic interUV I Ph3S+SbF " 6 penetrating network with the inorganic Si-O-Si network have been described. Such systems include the use of acrylate monomers or silane containing 7 urethane chains. " The use of cycloaliphatic diepoxide monomers to act as chemical link from inorganic to -CH2 o 01oý organic as well as provide an organic interpenetrating network has not been briefly described. Advantages of 0 such a cationic cure system include lack of oxygen inhibition during cure and improved adhesion due to less shrinkage, e.g., 2%, versus in comparison to 10Ph3S+SbF " 6 15% or more within a pure acrylate system. In this study, we report on the incorporation of diepoxide monomer materials into a tetraethoxysilane/ 3glycidoxypropyltrimethoxysilane sol-gel system. These monoepoxide and diepoxide materials undergo cationic polymerization in the presence of triarylsulfonium salts to form an inorganic and three dimensional polyether network (eq 1 & 2).
"--CH ,-::
(1)
(2) -- I
0
135
Mat. Res. Soc. Symp. Proc. Vol. 346. 01994 Materials Research Society
We report the preparation and characterization of these novel materials by
Data Loading...
