Open AccessThe effect of residual acetate groups on the structure and properties of vinyl alcohol–ethylene copolymers
Author(s) -
Cerrada M. L.,
Benavente R.,
Pérez E.,
Pereña J. M.
Publication year - 2000
Publication title -
journal of polymer science part b: polymer physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.65
H-Index - 145
eISSN - 1099-0488
pISSN - 0887-6266
DOI - 10.1002/(sici)1099-0488(20000215)38:4<573::aid-polb9>3.0.co;2-1
Subject(s) - vinyl acetate , copolymer , vinyl alcohol , differential scanning calorimetry , ethylene vinyl acetate , polymer chemistry , materials science , dynamic mechanical analysis , crystallization , ethylene , chemical engineering , chemistry , composite material , organic chemistry , polymer , thermodynamics , catalysis , physics , engineering
Vinyl alcohol–ethylene (VAE) copolymers, commercially manufactured by hydrolysis of the corresponding vinyl acetate–ethylene copolymers, can contain small amounts of unhydrolyzed vinyl acetate. This article shows the influence of these residual groups on the structure of the resulting copolymers, studied by nuclear magnetic resonance and wide‐angle X‐ray scattering. Thermal and mechanical properties of these materials were investigated by differential scanning calorimetry, thermogravimetry, drawing behavior, birefringence measurements, and dynamic mechanical analysis. The structure of the copolymers is considerably affected by the volume of the residual acetate groups, bigger than that of the hydroxyl ones, which hinders the crystallization process. In relation to the thermal and mechanical properties, the temperature and enthalpy of melting as well as the Young's modulus and yield stress, decrease as vinyl acetate molar fraction increases. Moreover, the α and β relaxations are shifted to lower temperatures as residual content in the copolymer is raised. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 573–583, 2000