Compatibility, Processability and Cure Behavior of Benzil end Capped Acetylene Terminated Quinoxaline Oligomer with Acetylene Terminated Phenoxy Diluent
Abstract
Benzil end-capped acetylene terminated phenyl quinoxaline (BATQ-H) oligomer undergoes thermally initiated polymerization through its reactive acetylene groups. The cured resin is high temperature resistant and has a Tg of 330 deg C. However, it is difficult to process due to its lack of necessary flow and has an insufficient 'reaction window' for cure. To improve the processability, 10 and 20 weight percent of low molecular weight acetylene terminated phenoxy (ATP) is added to the BATQ-H and the blends were obtained by freeze-drying. The 80 BATQ-H/20 ATP and 90 BATQ-H/10 ATP (ATP containing both the monomer and the oligomer) exhibit Tgs of 74 deg C and 111 deg C, respectively. Cure-phase diagram of the BATQ-H/ATP blends show availability of sufficient time for processing before vitrification occurs, thus providing an expanded reaction window. Complex viscosities of BATQ-H and BATQ-H/ATP blends were determined isothermally on the Rheometrics instruments using parallel plates mode. The starting viscosity of BATQ-H is 10000 - 100,000 poise at 190 deg C when measured at a frequency of 10 radians/sec and rise sharply at this temperature. Whereas the viscosities of 80/ 20 and 90/10 blends start at 100 poise and rise at a much slower rate, providing additional time before the oligomers become unprocessable due to high viscosities. The dynamic shear moduli of 80 BATQ-H/20 ATP and 90 BATQ-H/10 ATP cured blends were determined by Torsion Impregnated Cloth Analysis (TICA) specimens. The data suggest 275 deg C as the upper limit for end-use temperature.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1981
- Accession Number
- ADA112702
Entities
People
- Ivan J. Goldfarb
- Steven S. Sikka
Organizations
- Wright Laboratory