RESEARCH AND DEVELOPMENT OF HIGH TEMPERATURE STRUCTURAL ADHESIVES
Abstract
Constructive pyrolysis of laminates at 1800 F in an Ar atmosphere results in a major improvement in oxidation resistance when exposed to circulating air at either 650 or 900 F. A silicone laminate, after this treatment, lost only 1.5% of its remaining resin content after 33 hr at 900 F. Despite the high pyrolysis temperature, the laminates retained a large amount of their organic resin. The low resistivity after pyrolysis, ranged from 4 to 70 ohm-cm. The phenolic-181 E glass laminate had a room temperature flexural strength of just under 10,000 psi and a modulus of 5.4 million psi. Mechanism studies on the sulfide curing compounds indicate that the type of epoxy polymerization is dependent upon the S compound. Arsenic trisulfide appears to undergo a sulfur-oxirane oxygen exchange, as does thiourea and dithiocarbamate salts. Synthetic efforts have resulted in a polymer containing a -Si-O-Cochain by reaction of cobalt acetate with dialkoxysilane. Metal salts of 2- mercaptobenzothiazole were prepared and used to cure epoxy novolaks for mechanism studies and adhesive preparations.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1961
- Accession Number
- AD0259068
Entities
People
- Harold H. Levine