The viscoelastic properties of rubber–resin blends. I. The effect of resin structure

Abstract

SynopsisBlends 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 6 vs. temperature, the addition of a compatible resin produces a pronounced shift of the tan 6 peak to a higher temperature and reduces the modulus in the rubbery plateau. An incompatible resin results in a minor shift in the tan 6 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,, about 900, is shown to be incompatible with natural rubber but compatible with styrene-butadiene rubber. A cycloaliphatic poly(viny1 cyclohexane) resin, M,,, about 650, prepared by hydrogenating the polystyrene resin, is compatible with natural rubber, but incompatible with styrene-butadiene rubber. An alkylaromatic poly(tert-butylstyrene) resin, Mu 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.

Dynamic Mechanical and Morphological Study on Model Pressure Sensitive Adhesive Based on Poly(styrene-b-butadiene-b-styrene)

“…6 -9 Class and Chu reported the compatibility was dependent upon the structural similarity, and the concentration and molecular weight of the tackifier. 10 Akiyama investigated the phase behavior ofpoly(styreneb-isoprene-b-styrene) (SIS) based PS As, 11 · 12 and Sung and Chin reported rheological properties of some model PSAs. 13 Most research on PSA so far has been directed at the PSA systems whose elastomer was the natural rubber or the block copolymers of polystyrene and polyisoprene.…”

A Comparison of Tackified, Miniemulsion Core−Shell Acrylic Latex Films with Corresponding Particle-Blend Films: Structure−Property Relationships

“…11,12,13,14 TRs are bulky, low-molecular-weight molecules with a glass transition above room temperature, such as n-butyl ester of abietic acid 15 or pentaerythritol rosin ester derived from abietic acid. 16 TR can be incorporated into a PSA by dissolving it in a common solvent along with the polymer.…”

Synthesis and Application of Sorbic Acid Grafted Hydrogenated Dicyclopentadiene Hydrocarbon Resin

“…The hydrocarbon resins develop the mobility of base polymer at taping process as a diluent, as well as improve the peel strength at peeling process. Many researchers [1][2][3][4][5][6][7][8][9] and we [10,11] investigated the mechanism of tackiness development by the addition of HCRs. Pressure-sensitive adhesives (PSA) are used for many different applications in the form of tapes, labels, decals, medical products, and others.…”