In‐Situ Fiberized Poly(ethylene terephthalate) as a Reinforcement to Poly(propylene) Matrix

Abstract

The reinforced poly(propylene) (PP)/poly(ethylene terephthalate) (PET) in‐situ fiberized composites were prepared by extrusion‐drawing‐injection molding. The influences of PET weight fraction (fw) on the PET fiberization, phase morphology, and mechanical properties of the composites, together with their functional mechanisms were studied by contrast to the normal‐blended materials without drawing. The results show that as the fw rises from 0 to 20%, the number of PET fibers increases, whereas their diameter and dispersity decrease till fw = 15% and then increase, and the number of remained PET particles tends to rise. These changes of PET fiberization and phase morphology with fw were attributed to the consequence of the combined actions of breakup, coalescence, and deformation of the PET dispersed phase in the PP matrix during the extrusion drawing. Correspondingly, the tensile strength (σt) and Young's modulus (E) of the in‐situ composites increase till fw = 15% and then decrease, with maximum gains of σt and E of about 20 and 70% relative to the neat PP, respectively. This σt/fw relation was ascribed to the counterbalanced result between the reinforcing effect of the dispersed phase on matrix and the interfacial flaw effect of two immiscible phases, while the E/fw relation was considered as a representation of the rigidizing effect of the fibers on the matrix being controlled by both their number and diameter.In‐situ PET fibres (PET/PP = 85/15) in an as‐drawn filament.magnified imageIn‐situ PET fibres (PET/PP = 85/15) in an as‐drawn filament.

Study of PET/PP/TiO2 microfibrillar‐structured composites, Part 2: Morphology and mechanical properties

“…Microfibrillar composites (MFC) that are reinforced by in situ formed polymer fibrils exhibit improved mechanical properties compared with the matrix polymer,21–24 as the polymer fibrils act as reinforcement for the polymer matrix. The incorporation of inorganic filler into microfibrillar‐structured composites may further influence the mechanical properties of the composites.…”

Recyclability of In Situ Microfibrillar Poly(ethylene terephthalate)/High‐Density Polyethylene Blends

“…offers an opportunity to obtain new polymeric materials with tailored properties. [2][3][4] However, most polymer blends are thermodynamically immiscible and also technologically incompatible, and form multi-phase systems during processing. This causes poor dispersion of the components and low interfacial adhesion which negatively affect the mechanical properties of the materials.…”

Essential Work of Fracture Parameters of in‐situ Microfibrillar Poly(ethylene terephthalate)/Polyethylene Blend: Influences of Blend Composition

“…[8,9] The engineering plastics for the microfibrillar blends consist of poly(ethylene terephthalate) (PET), polycarbonate (PC), and polyamide (PA) due to their good mechanical properties, high dimensional stability and moderate price. [7,10] The specific process of microfibrillar blends can be generally described in the following three Summary: An in-situ microfibrillar blend based on poly-(ethylene terephthalate) (PET) and polyethylene (PE) was fabricated through slit die extrusion, hot-stretching and quenching. The morphology of the PET in-situ microfibers, which were observed after the matrix was etched away, appears to be dependent on the blend composition at a fixed hot stretch ratio.…”

“…The in‐situ microfibers have significant reinforcement to the obtained blend whose morphology is similar with the so‐called in‐situ composite based on a thermoplastic and a thermotropic liquid crystalline polymer 8,9. The engineering plastics for the microfibrillar blends consist of poly(ethylene terephthalate) (PET), polycarbonate (PC), and polyamide (PA) due to their good mechanical properties, high dimensional stability and moderate price 7,10. The specific process of microfibrillar blends can be generally described in the following three steps:11–13 (1) melt blending of the starting neat polymers and extrusion, (2) cold drawing of the blend, and (3) subsequent annealing of the drawn blend at constant strain and at T 1 < T < T 2 , where T 1 is the melting temperature of the lower melting component and T 2 is that of the higher melting one.…”