Type of Document Dissertation Author Lee, Yong-Joon URN etd-06062008-162715 Title Structure-property behavior of novel high performance thermoplastic and thermoset structural adhesives and composite matrix resins Degree PhD Department Materials Engineering Science Advisory Committee
Advisor Name Title No Advisors Found Keywords
- molecular weight control
- flame resistance
Date of Defense 1995-01-15 Availability restricted Abstract
Soluble, thermally stable phosphorus containing polyimides have been synthesized to controlled molecular weights and well-defined phthalimide endgroups via solution imidization. They were characterized by intrinsic viscosity, DSC, TGA, and thermomechanical measurements. Molecular weight control was successful and these polyimides were thermally stable via dynamic TGA up to 500°C. Flame resistance was suggested by the 10-20 % of char yield observed in air at 750°C. Good tensile modulus (500-550 ksi) via stress-strain measurements and excellent adhesion to Ti-6AI-4V substrates through single lap shear tests was demonstrated.
Investigations of the effects of molecular weight and end group on thermal and mechanical properties of reactive amine terminated and non-reactive phthalic anhydride terminated PMDA-mBAPPO polyimides were pursued. Polyimides with non-reactive end groups do not crosslink and, hence, were essential for controlled processability. Rheological behavior was investigated with a parallel plate type viscometer and the results confirmed the thermoplastic nature of these systems.
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