Expandable Epoxy Application.
Abstract
Epoxy resins are widely used throughout the industry as the matrix in structural composites. Epoxides undergo the least amount of shrinkage during cure of the available composite matrices. However, this shrinkage does affect a reduction in the performance of the composite. This reduction in performance can be the result of poor adhesion between the matrix and the reinforcing fibers or the formation of stress concentrations in the matrix due to the presence of microcracks, both of which leads to the failure of the composite. Cyclic monomers which undergo expansion during a cationic ring opening polymerization have the potential of reducing or eliminating the shrinkage that occurs in epoxy resins. The expansion of the monomers during the polymerization process is due to the transformation of covalent bonds in the monomer ring to Van der Waals type interactions with the formation of the polymer. This expansion can also occur if the cyclic monomers are copolymerized with an epoxy, thus reducing or eliminating the shrinkage. The cyclic monomer chosen for this program was 3,9-bis (5'-norbornene-2'yl) - 1,5,7,11-tetraoxaspiro 5,5 undecane which showed the most promise in preliminary studies. The objectives of this program are to evaluate the effects of incorporating limited percentages of the bisspiro orthocarbonate in epoxy resins; To determine the improvements in subscale composite motor cases using a bisspiro/epoxy resin, and to determine the merit of fabricating pressure bottles using a layered procedure for their construction.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 25, 1986
- Accession Number
- ADA168669
Entities
People
- G. Rogowski
- T. F. Davidson
Organizations
- ARCO