High‐tensile‐strength polyvinyl alcohol films prepared from freeze/thaw cycled gels. Issue 15 (6th March 2014)

• Record Type: Journal Article
• Authors: Fukumori, Taishi; Nakaoki, Takahiko
• Is Part Of: Journal of applied polymer science. Volume 131:Issue 15(2014:Aug. 05)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2014-03-06
• Subjects: Polymers -- Periodicals; Polymerization -- Periodicals; 668.9
• DOI: 10.1002/app.40578
• Languages: English
• ISSNs: 0021-8995

Abstract

<abstract abstract-type="main"> <title>ABSTRACT</title> <p>The mechanical properties and molecular structure of a poly(vinyl alcohol) (PVA) film, which was obtained by eliminating water from a PVA hydrogel using repeated freeze/thaw cycles, were investigated by tensile tests, thermal analysis, and X‐ray diffraction measurements. The mechanical properties of PVA with 99.9% saponification were measured as a function of the number of freeze/thaw cycles performed. The tensile strength and Young's modulus increased and the elongation at break decreased with increasing freeze/thaw cycles. The tensile strength and Young's modulus of PVA films obtained after seven freeze/thaw cycles were as high as 255 MPa and 13.5 GPa after annealing at 130°C. Thermal analysis and X‐ray diffraction measurements revealed that this is because of a high crystallinity and a large crystallite size. A good relationship between the tensile strength and the glass transition temperature was obtained, regardless of the degree of saponification and annealing conditions. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. <bold>2014</bold>, <italic>131</italic>, 40578.</p> </abstract>