Physio-chemical degradation of thermally aged
hypalon glove samples
Kennard V. Wilson Jr.
a,
)
, Bettina L. Smith
a
, John M. Macdonald
b
,
Jon R. Schoonover
a
, Julio M. Castro
c
, Mark E. Smith
a
,
Michael E. Cournoyer
b
, Rob Marx
a
, Warren P. Steckle Jr.
a
a
Materials Science and Technology Division, Los Alamos National Laboratory, PO Box 1663, MS E549,
Los Alamos, NM 87545, USA
b
Nuclear Materials and Technology Division, Los Alamos National Laboratory, PO Box 1663, MS E539,
Los Alamos, NM 87545, USA
c
Health, Safety, and Radiation Protection Division, Los Alamos National Laboratory, PO Box 1663,
MS E503, Los Alamos, NM 87545, USA
Received 13 October 2003; received in revised form 21 January 2004; accepted 29 January 2004
Abstract
Attenuated total reflection (ATR) infrared spectra have been analyzed using multivariate curve resolution (MCR) to capture the
chemistry of the thermal degradation in the aging of chlorosulfonated polyethylene (Hypalon
Ò
) glove samples. The analysis
demonstrates the primary degradation pathways to be oxidation (formation of ketones and carboxylic acids), dehydrochlorination
with formation of eC]Ce groups, and polymer crosslinking with changes in the CeH functional groups. From the multivariate
analysis, the dominant degradation pathway involves carbonecarbon double bond formation and oxidation to form ketones. The
tensile properties (modulus and elongation at break) demonstrate stiffening of the material with aging time. The dynamic mechanical
data show that the storage modulus and mechanical loss tangent are also strongly affected with aging due to a hardening of the
material. Taken together the mechanical and ATR data indicate that in thermal aging hypalon degrades by dehydrochlorination and
loss of eSO
2
Cl functionality with eC]Ce formation, oxidation, and crosslinking causing the material to harden and become brittle.
Published by Elsevier Ltd.
Keywords: Chlorosulfonated polyethylene; Hypalon; Thermal aging; Thermal degradation; FTIR-ATR
1. Introduction
The ability to correlate changes in mechanical
(physical) properties with degradation chemistry is
important in gauging the acceptable standards for
polymeric gloves used in a laboratory glovebox environ-
ment. Towards this aim an accelerated aging study
has been performed on chlorosulfonated polyethylene
(Hypalon
Ò
, hereafter referred to as hypalon) and
hypalon/lead oxide-Neoprene/hypalon tri-layered gloves
to assist in determining both the shelf life and use life of
these gloves in a thermal and oxidative environment
[1,2]. The thermal environment is just one of the con-
ditions (vacuum, organic solvent, acidic or basic, and
radiolytic being others) in which these gloves are utilized,
but this initial study represents an important baseline in
the Improving Glovebox Glove Project at Los Alamos
National Laboratory.
Hypalon is a chlorosulfonated polyethylene manufac-
tured by DuPont, resistant to interactions with alcohols
and strong acids and bases. This material also exhibits
excellent ultraviolet light and oxygen stability. In addi-
tion to glovebox gloves, this polymer has additional uses
such as in lining and sheath materials, coatings, and
adhesives. The layered hypalon/lead oxide-neoprene/
hypalon material exhibits the same chemical resistances
and stability, but possesses additional utility in radiolytic
environments.
)
Corresponding author. Tel.: C1-505-667-7236; fax: C1-505-667-
8109.
E-mail address: kvw@lanl.gov (K.V. Wilson Jr.).
0141-3910/$ - see front matter Published by Elsevier Ltd.
doi:10.1016/j.polymdegradstab.2004.01.002
Polymer Degradation and Stability 84 (2004) 439e449
www.elsevier.com/locate/polydegstab