2021-09-25
Hydrocarbon resins, which are defined as low molecular weight, amorphous, and thermoplastic polymers, are widely used as tackifiers for various types of adhesives, as processing aids in rubber compounds, and as modifiers for paint and ink products, and for use in plastics polymers such as isotactic polypropylene. Recently, the quantities of the hydrocarbon resin׳ raw materials which are the side products from naphtha cracking process have decreased because of light-feed cracking such as gas cracking, so new raw materials for hydrocarbon resin production are essential. To be satisfied with the previously mentioned factors, the substitution of hydrocarbon resin raw materials with renewable resources is a worthy consideration. Moreover, new hydrocarbon resin having high adhesion performance, low specific gravity, and good compatibility with various polymers has been requested in various adhesives.
To meet those requests, in this study, propylene instead of side product from naphtha cracking as main raw material of hydrocarbon resin were partially used. The propylene serves as a new, sustainable raw material and was successfully grafted onto dicyclopentadiene. The reaction of the propylene with dicyclopentadiene was confirmed because, according to NMR and FT-IR analyses, a pendant methyl-propylene group exists in the structure of the propylene-grafted, hydrogenated dicyclopentadiene hydrocarbon resin. To establish an optimal production condition regarding the propylene-grafted, hydrogenated dicyclopentadiene hydrocarbon resin, numerous experiments were conducted according to the mole ratio of the raw materials and the polymerization temperature. The propylene-grafted, hydrogenated dicyclopentadiene hydrocarbon resin that was manufactured according to optimal conditions results in a lower specific gravity and a high molecular weight, whereby the advantages of the adhesion properties of an SIS-based pressure-sensitive-adhesive are exploited. When the propylene-grafted, hydrogenated dicyclopentadiene hydrocarbon resin was formulated with the SIS-based pressure-sensitive-adhesive, both the heat stability and the shear-adhesion strength are sound.
