INTERPHASE INTERACTIONS AND MECHANICAL PROPERTIES OF GLASS FIBER REINFORCED BLENDS OF POLYETHYLENE TEREPHTHALATE WITH THERMOPLASTIC POLYESTER ELASTOMER

The effect of adding 0.9 wt% of a diisocyanate chain extender (CE) on rheological and mechanical properties of PET/PTEP blends, reinforced with a 30 wt% short glass fiber (GF) is studied. TPEE concentration in the blends was varied from 7 wt% to 50 wt%, which affected changes in their phase structure. Composites were obtained through reactive extrusion using a twin screw mixing reactor with unidirectional screw rotation. Interfacial adhesion in the “polyester binder – GF surface” system was estimated using micromechanical tensile tests of mixed polyester matrices and glass fiber reinforced composites that are based on them, as well as using the relaxation spectrometry data. It was determined that CE has a strong effect on the mechanical properties of composites with a different phase structure, increasing their mechanical tensile and bending capabilities up to 1.5 times, and increasing Charpy impact strength of materials up to 1.6 times. The reasons for these effects are an increase in the average length of GF in composites containing CE, as well as intensified interaction between interfacial adhesive polyester binder and GF surface.

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