B. Dao et al., THE UTILITY OF 2-NAPHTHOL DERIVATIVES AS DIELS-ALDER BASED CO-REACTANTS FOR BISMALEIMIDES, High performance polymers, 9(4), 1997, pp. 413-427
A number of 2-naphthols were found to undergo a Diels-Alder addition r
eaction with maleimides. This reaction can be used to bring about the
cure of bismaleimides. The simplest co-reactant prepared in this work
was 7-allyloxy-2-naphthol and satisfactory cures were obtained with ap
propriate bismaleimides. However, the laminate coupons made using this
system had lower thermal stability than those of a comparable system
using the commercial co-reactant Matrimid 5292B. The performance of th
is new chemistry was further tested by incorporating the naphthol/male
imide Diels-Alder addition structure into two other co-reactants. The
most successful of these compounds (the diallyl ether of the adduct ma
de from Diels-Alder addition of 2,7-dihydroxynaphthalene and 4-hydroxy
phenylmaleimide) produced cured neat resin samples having T(g)s 30 deg
rees C higher than those of a comparable system cured with the standar
d bismaleimide co-reactant (Matrimid B) and had slightly higher tensil
e strength and modulus than this system. The fact that these laminate
coupons had better thermal performance than the system using commercia
l co-reactant showed that the presence of the Diels-Alder adduct struc
ture in the resin backbone was not detrimental to the normal performan
ce of ene cured bismaleimides. On the other hand the same structure in
corporated into phenylethynyl end-capped resins was found to compromis
e its thermal stability.