Novel Insights into Pressure‐Sensitive Adhesives Based on Plant Oils

Abstract

This work investigates the synthesis of bio‐based pressure‐sensitive adhesives and their characterization in terms of mechanical properties relevant to processing and application. The synthesis of monomers based on various fatty acids derived from vegetable oils as renewable feedstock via a one‐step, a two‐step, and a three‐step route is described. The resulting monomers are polymerized via free radical polymerization resulting in high molecular weight polymers with adhesive properties. Adhesives are also obtained as aqueous dispersions by means of miniemulsion polymerization. In particular, the monomer acrylated methyl oleate (4ac) and the thereof derived polymer are intensively studied. The synthesized homopolymers show characteristic mechanical and adhesive properties similar to conventional pressure sensitive adhesives.

Photopolymerization of Functionalized Monomers Derived from Oleic Acid

“…The organic phase was neutralized with 1 M sodium hydroxide, washed with water, and dried over magnesium sulfate. Finally, the solvent was evaporated, and the residue was dried at room temperature under vacuum for 24 h. The raw hydroxy acrylated methyl oleate (1) was obtained in 86% yield [4,12].…”

“…Finally, the solvent was evaporated under vacuum, and the residue was dried under vacuum at room temperature for 24 h resulting in 80% yield of 10(9)-bromo-9(10)-[(1-oxo-2-propen-1-yl)oxy] octadecanoic acid methyl ester (3) [4][5][6]. Column chromatographic purification of the raw product of 3 using an ethyl acetate n-hexane mixture (vol:vol = 1 : 5) as eluent resulted in 52% yield of purified 3.…”

“…Although vegetable oils have been described to design alkyd resins for a long time, modern applications of these well known resources, require more research to introduce additional functional groups exhibiting a higher reactivity compared to the available double bond in the fatty acid. One example disclosed the introduction of an acrylate group into methyl oleate [3][4][5][6]. The latter was chosen as a simple model to demonstrate feasible functionalization of vegetable oils.…”

“…Both the hydroxy acrylated methyl oleate and the bromoacrylated methyl oleate bear a long aliphatic chain. They have been investigated separately as monomers in free radical polymerization [3][4][5][6].…”

“…1). Although the hydroxyacrylated methyl oleate (1) and the bromoacrylated methyl oleate (3) are known from literature [3][4][5][6]12], the hydroxymethacrylated methyl oleate (2) and the bromomethacrylated methyl oleate (4) are new compounds. In the following, their synthesis is described and the purity of (meth)acrylated methyl oleates investigated by UPLC/MS.…”