The effects of physical ageing on the crazing of polyphenylquinoxaline(PPQ E) films were studied. The DSC endothermic peak at the glass transition region of the samples was interpreted in terms of the cohesional entanglement theory. The free volume cavity size and free volume intensity of the samples were characterized by positron annihilation life spectroscopy. The difference in free volume cavity size and free volume intensity between two samples reflect the strength and density of cohensional entanglement point. The critical strain for craze initiation and craze stability depended on physical ageing of the samples. The relationships between physical ageing and crazing were interpreted initially.
The waterborne particles of bisphenol A epoxy resin were prepared by the phaseinversion technique, and the effects of the concentration of the synthetic polymeric emulslfleron the particles size and structure were discussed. At lower concentration of the emulsifier,the bigger molecular sieves alike particles were obtained, on the contrary, the smallerparticles with some aggregation were prepared at higher concentration of the emulslfler. Theformation mechanism of different particle sizes and structure at different concentrations of theemulsifier was proposed. presides, the probable model of the aggregation was also brieflypresented.
