Structure and Properties of a Metallocene Polypropylene Resin with Low Melting Temperature for Melt Spinning Fiber Application

Abstract

An isotactic polypropylene (iPP-1) resin with low melting temperature (Tm) is synthesized by a metallocene catalyst and investigated for melt-spun fiber applications. The structure, thermal and mechanical properties, and feasibility of producing fibers of a commercial metallocene iPP (iPP-2) and a conventional Ziegler–Natta iPP (iPP-3) are carefully examined for comparison. Tm of iPP-1 is about 10 °C lower than the other two samples, which is well addressed both in the resin and the fiber products. Besides, the newly developed iPP-1 possesses higher isotacticity and crystallinity than the commercial ones, which assures the mechanical properties of the fiber products. Thanks to the addition of calcium stearate, its crystal grain size is smaller than those of the two other commercial iPPs. iPP-1 shows a similar rheological behavior as the commercial ones and good spinnability within a wide range of take-up speeds (1200–2750 m/min). The tensile property of fibers from iPP-1 is better than commercial ones, which can fulfill the application requirement. The formation of the mesomorphic phase in iPP-1 during melt spinning is confirmed by the orientation and crystallization investigation with wide angle X-ray diffraction (WAXD), which is responsible for its excellent processing capability and the mechanical properties of the resultant fibers. The work may provide not only a promising candidate for the high-performance PP fiber but also a deep understanding of the formation mechanism of the mesomorphic phase during fiber spinning.

İzo- ve Sindiyotaktik Polipropilenlerin Reolojik Davranışının Karşılaştırılması

“…Further, sPP is a semicrystalline material and exhibits a low degree of crystallinity compared to iPP. Because isotacticity degree is deliberated as the basic parameter that has an impact on the crystallinity of polymers (Amer et al, 2015;Xu et al, 2019). In other words, with some exclusions, higher crystallinity accompanied by higher density and stiffness (Amer et al, 2015).…”

Single-Sided Jacquard Knit Fabric Development and Seamless Ski Underwear Zoning Design based on Body Mapping Sportswear

“…Among them, the main material of yarn used in group T 1 fabric is polyester and that used in group T 2 is DRYARN, of which DRYARN is the ultra-fine polypropylene fibre developed by Italian manufacturer Aquafil using metallocene polypropylene. Due to the use of Avant M catalyst [18], its relative molecular weight distribution is narrow so that it has excellent air permeability, radiation resistance, and insulation performance. Therefore, the a-f fabrics of group T 2 have better air permeability and moisture permeability, which can better help human body to absorb moisture and sweat and enhance human comfort.…”