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#2009 The Society of Polymer Science, Japan
High Performance Polyamide 6 Fibers Using Polycarbonate Based Thermoplastic Polyurethane Thin FilmCoatings- a Novel Method
By Baiju JOHN,1 Ken KOJIO,2 and Mutsuhisa FURUKAWA1;
Polycarbonate based thermoplastic polyurethanes (CPU2) were prepared and coated onto polyamide 6 (PA 6) bers. The CPU2 thin lm coatings were prepared by dipping the PA 6 bers into a viscous CPU2 adduct and cured at 100 C for 12 h.
Both the tensile strength and the elongation at break of the CPU2 thin lm coated PA 6 bers (CPU2-PA6) increased although both the magnitudes of CPU2 are much lower than for the original PA 6 bers. FE-SEM observation revealed that there existed an interface interaction region of 10 mm at the interface of PA 6 ber and the CPU2 thin lm coating. Generally speaking, it is considered that the break of PA 6 bers is due to the formation of the micro-cracks on the ber surface when it is under a tensile load. The coating of CPU2 onto the PA 6 bers reduced the formation of micro-cracks during the elongation process, resulted in the improvement of the mechanical properties. Also, the CPU2-PA6 bers when exposed to weathering tests to check the weathering resistance, showed an increase in the tensile strength for 050 h of exposure. This was due to the UV light induced crystalline transformation, i.e., from the crystalline phase to the crystalline phase. The CPU2-PA6 bers almost retained the strength even after 200 h of exposure in a weatherometer. The crystalline transformations due to the UV irradiations have not been reported yet. Also, the CPU2 showed good adhesion property with the PA 6 lms. The blending with various polymers or composites is generally employed for the performance enhancement of PA 6 bers. On the contrary, the method employed in this study improved the performance of PA 6 bers without changing its inherent morphological properties.
KEY WORDS: Polyamide 6 Fiber / Polyurethane Thin Film / Coating / Micro-cracks / Interface Interaction / Plastic-type Break /Metallic-type Break / Weathering Tests /
Polyamide bers (PAs) are used for a wide variety of applications. They include the textile industry, engineering applications, biomedical and marine applications. The properties of PAs are the high melting point, good mechanical strength,...