PPQ Adhesives for Large Area Bonding of Titanium Alloys

摘要

A Diels-Alder reaction was investigated as a means to crosslink polyphenyl-quinoxalines (PPQ) which were intended for use as adhesives in large area bonding of titanium alloys. Two promising candidate polymers were identified for process development studies. Double lap-shear specimens were press cure fabricated from the adhesives and Ti-6Al-4V adherends which demonstrated room temperature strengths of 4000 psi and elevated temperature strengths of 2800 psi and 2000 psi at 450 F and 550 F, respectively. Detailed evaluation studies were conducted which included stress durability determinations, crack extension measurements, peel strength measurements and blister detection tests which demonstrated applicability for preparing large area bonded specimens. The results of the detailed testing indicated that the crosslinked PPQ adhesive possessed toughness and that large area bonded specimens can be press cure fabricated. (Author)