Report to T & N Materials Research Ltd.

S F Bush

Summary

A large number of 3 mm plaques have been made and tested using commercial resin formulations and a variety of potential reinforcements.

The resin formulations were modified by the addition of a diol, ethylene glycol, or triol, glycerol, and initially different catalyst concentrations were explored. These modifications were designed to alter the cure rate and flexural modulus with unpredicted effects on the strength.

The reinforcements used were available commercial types: 1.5 mm fibres sized for urethane applications; 3 and 6 mm fibres sized for olefine applications; hammer milled glass of approximmately 150 μ in equivalent diameter; wood flour of maybe 20 to 50 μ equivalent diameter.

A number of post-curing regimes have also been explored. These involve some hours of heating at 100 and 150 ^oC broadly corresponding to temperatues likely to be attained near an engine.

Flexural strengths and flexural moduli have been determined by 3 point bending of 60 x 10 x 3 mm strips. Reasonable consistency has been obtained particularly when allowance is made for the occasional cavity present on the breaking section. For this reason it is thought that the strength results are conservative, tending if anything to underestimate the potential strength.

See also the section on Polymer Morphology & Fibre Reinforcement Mechanisms.