Pressure-sensitive adhesives based on soybean fatty acids

Abstract

A new class of renewable pressure-sensitive adhesive (PSA) designed and developed from soybean oil was reported in this study. Soybean oil was epoxidized and hydrolysed selectively on the ester groups to afford a mixture of epoxidized fatty acids (EFAs) which were characterized by FTIR and 1 H NMR spectroscopy. The EFA mixture without further purification was then polymerized directly in the presence and absence of a small amount of dicarboxylic acid compounds to afford hydroxyl-functionalized polymers. The peel strength, loop tack, shear strength and viscoelastic properties of the resulting (co)polymers revealed that the (co)polymers were suitable for PSA applications. The new PSAs could be fully bio-based and potentially biodegradable, and their preparation and application did not require the use of an organic solvent or a toxic chemical, thus being environmentally friendly.

Development and Characterization of Pressure-Sensitive Adhesives from Dimer Acid and Epoxides

“…The 90°peel, shear, and loop tack tests of the PSA samples were performed in accordance with the conditions and methods described in our previous studies (14,15).…”

“…After one or four weeks, the sample tapes were taken out of the incubator and conditioned at 23 ± 1°C and 40 ± 5 % RH for 16 h. PSA specimens were then prepared from the aged sample tapes and measured for their peel strength and loop tack in accordance with the methods described previously (14,15).…”

“…A mixture of DA and each of the epoxides was polymerized and completely cured under the conditions described in Table 1. AMC-2 has been demonstrated to be an efficient catalyst for accelerating the reaction between a -COOH and an epoxy group in studies by our research group (14,15) and others (4), and was used as the catalyst for the polymerization of the DA-epoxide mixtures in this study.…”

“…PSAs can also be developed from the polymerization of an AB-monomer, epoxidized oleic acid (12,13). It has been demonstrated that a mixture of epoxidized fatty acids (EFAs) can be efficiently produced from the selective hydrolysis of epoxidized soybean oils (14). Polymerizations of the EFA mixture in the presence or absence of a small amount of dicarboxylic acids readily afforded PSAs with superior properties (14).…”

“…It has been demonstrated that a mixture of epoxidized fatty acids (EFAs) can be efficiently produced from the selective hydrolysis of epoxidized soybean oils (14). Polymerizations of the EFA mixture in the presence or absence of a small amount of dicarboxylic acids readily afforded PSAs with superior properties (14). Reactions of dicarboxylic acids with epoxidized soybean oils were also found to generate superior PSAs (15).…”