Mechanical properties of extruded glass fiber reinforced thermoplastic polyolefin composites

Abstract

Engineered structural materials are required to feature a combination of deformability (ductility) and strength to be considered damage‐tolerant for safety‐critical applications. These two mechanical properties, however, tend to be mutually exclusive, encouraging optimization of the trade‐off between strength and toughness. In this report, an elastomer and a glass fiber were incorporated into a blend of two grades of polypropylene (PP) to improve matrix toughness through both intrinsic and extrinsic toughening mechanisms. This study investigates the impact resistance (at 23°C and −30°C), and strength, stiffness, deformability, and processability of extruded compatibilized glass fiber reinforced thermoplastic polyolefin (TPO) composites at 23°C. For the hybrid composites contribution of different toughening mechanisms in attainment of the final impact strength is governed by the testing temperature and processing (extruder screw) speed. The intrinsic toughening mechanism induced by the presence of the ethylene α‐olefin copolymer is suppressed by the introduction of glass fiber at 23°C, irrespective of screw speed and screw configuration design. The heat distortion temperature (HDT), flexural modulus, and tensile strength exhibit a marked improvement by glass fiber inclusion at 23°C. By evaluating the performance of the composites at −30°C, it was observed that the impact energy of the elastomer modified hybrid composites may be enhanced in the same manner as the glass fibers toughen the brittle unmodified PP matrix. It was noted that contrary to the tensile properties at break, the yield behavior of the composites containing fibers, severely shortened, is independent of the presence of the fibers at 23°C.

Mechanical and viscoelastic properties of polyethylene‐based microfibrillated composites from 100% recycled resources

“…Therefore, the generated fibrillar structure of rPET and rPA shows a noticeable reinforcing effect in the rPE material. These results are comparable with the enhancements that short glass fibers or talc particles could induce in the conventional composites 37–40 . The impact strength of rPE was suppressed in the presence of fibrillated rPET and rPA structure which is expected in thermoplastic based composites 37–40 .…”

“…These results are comparable with the enhancements that short glass fibers or talc particles could induce in the conventional composites. [37][38][39][40] The impact strength of rPE was suppressed in the presence of fibrillated rPET and rPA structure which is expected in thermoplastic based composites. [37][38][39][40] Of note, the reduction of impact strength is less severe in the MFCs reinforced with rPET fibrils than those containing rPA fibrils.…”

“…[37][38][39][40] The impact strength of rPE was suppressed in the presence of fibrillated rPET and rPA structure which is expected in thermoplastic based composites. [37][38][39][40] Of note, the reduction of impact strength is less severe in the MFCs reinforced with rPET fibrils than those containing rPA fibrils. The finer fibrils of rPET could have compensated the decrease of the impact strength to some extent compared to rPA fibrils.…”

Extrinsic toughening of recycled carbon fibers in polypropylene composites in the absence of plasticity penalty

“…Nevertheless, to gain popularity in mass-produced passenger vehicles, the major drawbacks of carbon fibers, which are their high cost and energy intensity of their production, must be resolved. [4][5][6][7][8][9][10][11] Recycling carbon fibers from out-of-date prepregs, endof-life components, manufacturing cutoffs, and other CFRP wastes increases the popularity of carbon fibers and brings added value to their wastes. While the manufacturing cost of virgin carbon fibers currently lies between 15 and 30 USD lb -1 , reclaimed carbon fibers from wastes cost up to 70% less to produce.…”

Mechanical properties and foaming behavior of polypropylene/elastomer/recycled carbon fiber composites

“…Toughening by means of an elastomer and fiber bridging are examples of this mechanism in polymer compounds and composites. [ 1–4 ]…”