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The viscoelastic properties of rubber–resin blends. I. The effect of resin structure
Author(s) -
Class J. B.,
Chu S. G.
Publication year - 1985
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1985.070300229
Subject(s) - materials science , natural rubber , polystyrene , adhesive , composite material , elastomer , viscoelasticity , styrene butadiene , cyclohexane , styrene , modulus , dynamic mechanical analysis , polymer chemistry , polymer , copolymer , chemistry , organic chemistry , layer (electronics)
Blends of elastomers with the proper concentration of appropriate low molecular weight resins exhibit performance as pressure sensitive adhesives. Viscoelastic properties, which may be related to adhesive performance, were measured on 1:l blends of rubber and resin using a mechanical spectrometer. Significant differences in viscoelastic properties were observed depending upon the resin structure. On plots of G′ and tan δ vs. temperature, the addition of a compatible resin produces a pronounced shift of the tan δ peak to a higher temperature and reduces the modulus in the rubbery plateau. An incompatible resin results in a minor shift in the tan δ peak of the elastomer along with the appearance of a second peak at higher temperature, attributed to a second phase which is predominantly resin. Also, the modulus is increased in the rubbery plateau. A polystyrene resin, M w about 900, is shown to be incompatible with natural rubber but compatible with styrene–butadiene rubber. A cycloaliphatic poly(viny1 cyclohexane) resin, M w about 650, prepared by hydrogenating the polystyrene resin, is compatible with natural rubber, but incompatible with styrene‐butadiene rubber. An alkyl‐aromatic poly( tert ‐butylstyrene) resin, M w about 850, which is intermediate in aromaticity between the aromatic polystyrene resin and the cycloaliphatic poly(viny1 cyclohexane) resin, is compatible with both natural rubber and styrene‐butadiene rubber. Therefore, the structure of the resin is very important in adjusting the viscoelastic properties of a rubber–resin blend to achieve pressure sensitive adhesive performance.