Fluoropolymer microstructure and dynamics: Influence of molecular orientation induced by uniaxial drawing

POLYMER

卷:91

Article

Miranda, Daniel F.¹  Yin, Chaoqing¹  Zhang, Shihai²  Runt, James¹ 

[1] Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA

[2] PolyK Technol LLC, 2124 Old Gatesburg Rd, State Coll, PA 16803 USA

关键词: Uniaxial drawing;    Polymer crystallization;    Dielectric spectroscopy;   

DOI  :  10.1016/j.polymer.2016.03.057

来源: Elsevier

【 摘 要 】

Fluorinated semi-crystalline polymers are attractive for dielectric film applications due to their chemical inertness and high thermal stability. In the present investigation we explore the influence of orientation induced by uniaxial drawing on the crystalline microstructure and relaxation processes of poly(ethylene-tetrafluoroethylene) (ETFE), in order to ascertain how morphological control can benefit polymer dielectric design. When drawn below or near the T-g, the crystallinity of the drawn films is unchanged, and oriented amorphous structures and crystalline microfibrils form at high draw ratios. This orientation slows segmental relaxation, reflected by an increase in the dynamic T-g. When drawing above T-g, the films undergo strain-induced crystallization at high draw ratios. For these films, an increase in dynamic T-g is also observed, in addition to a second segmental relaxation process, appearing as a shoulder on the primary process. We propose that this represents a contribution from a rigid amorphous fraction, having slowed chain dynamics. (C) 2016 Elsevier Ltd. All rights reserved.

【 授权许可】

Free