<scp>UV</scp> ‐curable pressure‐sensitive adhesives derived from functionalized soybean oils and rosin ester

Abstract

Abstract Functionalized plant oils such as epoxidized soybean oil ( ESO ) are widely used in plastic industries as additives and are available for more value‐added applications. Pressure‐sensitive adhesive ( PSA ) derived from petroleum feedstocks has a huge market ranging from tapes to packaging. Here we show a sustainable PSA derived from ESO /dihydroxyl soybean oil ( DSO )/rosin ester (Sylvalite) via UV ‐initiated copolymerization. The ether crosslinks derived from cationic polymerization of ESO and copolymerization between ESO and DSO (or rosin ester) were demonstrated using 1 H NMR , 2D 1 H– 1 H COSY NMR , electrospray ionization mass spectrometry and thermal analyses (differential scanning calorimetry and thermogravimetric analysis). The PSA was formulated by modulating the ratio of ESO / DSO /rosin ester to achieve high performance. At a UV dose of 5.1–5.4 J cm −2 and 0.3–3% (w/w) of a photoinitiator, i.e. [4‐(2‐hydroxy‐1‐tetradecyloxy)‐phenyl]phenyliodonium hexafluoroantimonate, the PSA at a ratio (by weight) of 1:1:0.7 ( ESO / DSO /rosin ester) recorded the highest peel and loop tack strength, which was comparable to a commercial PSA , Scotch Magic Tape, and showed much stronger shear strength (&gt;30 000 min) than the commercial tape (10 000 min). The high‐shear rheological behavior and excellent thermal stability of the PSA were also demonstrated. © 2012 Society of Chemical Industry