J. Kubo et al., INHIBITION OF DEGRADATION IN STYRENE-BASED THERMOPLASTIC ELASTOMERS BY HYDROGEN-DONATING HYDROCARBONS, Polymer degradation and stability, 45(1), 1994, pp. 27-37
The effects of hydrogen-donating hydrocarbon additives derived from pe
troleum (HHAPs) on styrene-based thermoplastic elastomers, styrenebuta
diene-styrene (SBS) and styrene-isoprene-styrene (SIS), during mixing
at 180 degrees C in air were investigated and the following results we
re obtained: (1) Changes in torque, temperature, gel fraction, mechani
cal properties and molecular weight distribution were investigated for
SBS (crosslinking is the main cause of degradation), and mechanical p
roperties and molecular weight distribution were studied for SIS (scis
sions are the main cause of degradation). (2) The obvious effects agai
nst these types of degradation can be attributed to the high radical s
cavenging abilities of the additives. Thus, the inhibiting effects cor
respond precisely to the reaction rates with DPPH (2,2-diphenyl-1-picr
ylhydrazyl). HHAPs are new conceptual inhibitors because of their pure
hydrocarbon constituents without functional groups containing heteroa
toms, and they are interesting enough to be investigated further.