Abstract
Polyamides were synthesized at β60Β°, β40Β°, β20Β°, and 0Β°C from sebacyl bisketene and 1,6βhexamethylenediamine in either acetone or methylene chloride. At the lower reaction temperatures oligomers predominated in solution but at 0Β°C the product was crosslinked. The polyamides were subjected to mβcresol extraction at elevated temperatures for up to 14 days. The mβcresol soluble and insoluble fractions were characterized by weight, infrared spectroscopy, dilute solution viscosity, and gel permeation chromatography. Infrared analysis of the soluble and insoluble portions showed the degree of branching of the polyamide, identified the branching point at the secondary amide proton position, and gave an indication of the degree of branching required before insoluble products resulted. Dilute solution viscosity and gel permeation chromatography were used to demonstrate the existence of low molecular weight (M~w~) oligomer species in the soluble portion. Differential scanning calorimetry experiments revealed that polyamides synthesized below their glass transition temperature would not crystallize which resulted in abnormal thermal characteristics. Annealing at elevated temperatures allowed crystallization to occur and the expected thermal character to develop.