A poly(vinyl alcohol)/poly(stearyl acrylate) core‐shell fibers with robust performance realized by taking advantages of the phase change property

Abstract

A phase change fiber with long‐term stability, temperature dependent transparency and melt‐healing properties were prepared using polyvinyl alcohol (PVA) as the shell layer and polystearyl acrylate (PSA) lightly crosslinked by ethoxylated trimethylolpropane triacrylate (ETPTA) as the core layer. It was found the PVA/P(SA‐ETPTA) core‐shell fiber exhibited a melt enthalpy of 43 J/g (coagulation bath temperature −15 °C, core layer diameter 0.2 mm, spinning rate 1.0 mm/s) and an extremely high stability after 100 heating–cooling cycles. The as‐spun core‐shell fiber was fragile, but the flexibility was greatly improved after it was drawn to 800% of the original length. The PVA shell forming tunneling for the P(SA‐ETPTA) core layer, which could heal after fracture on condition of PSA melting. The melting and crystallization of PSA side chains enabled a temperature dependent light transmittance of the PVA/P(SA‐ETPTA) fibers, which was ascribed to the phase separation between PSA and PETPTA around the melting point of the PSA composition. As a whole, the core‐shell fibers showed robust performance as a phase change fiber. Further aggregate structure and orientation structure investigation on the PVA/P(SA‐ETPTA) fiber was detected by wide angle X‐ray diffraction and small angle X‐ray scattering.

Synthesis of poly(n-alkyl acrylamides) and evaluation of nanophase separation effects by temperature-dependent infrared spectroscopy

“…These special properties are also found in poly(n-alkyl methacrylate) [1] as well as poly(n-alkyl acrylamide) [2]. Homo-and copolymers that show nanophase separation effects have been investigated for many different applications, including gaspermeation membranes [6][7][8][9], Langmuir-Blodgett films [10][11][12], shape-memory polymers [13][14][15][16], and adhesive modifiers [17], and in other contexts in which their phasechange behavior is useful [18][19][20].…”