Pressure-Sensitive Adhesives from Renewable Triblock Copolymers

Abstract

ABA triblock copolymers were prepared using the renewable monomers menthide and lactide, by sequential ring-opening polymerizations. Initially, hydroxy telechelic polymenthide was synthesized by the diethylene glycol-initiated and tin(II) ethylhexanoate-catalyzed polymerization of menthide. The resulting 100 kg mol−1 polymer was used as a macroinitiator for the tin(II) ethylhexanoate-catalyzed ring-opening polymerization of d,l-lactide. Two polylactide−polymenthide−polylactide triblock copolymers were prepared with 5 and 10 kg mol−1 polylactide end blocks. Transesterification between the two blocks, and polylactide homopolymer formation were minimized, and triblock copolymers with narrow molecular weight distributions were produced. Microphase separation in these systems was corroborated by differential scanning calorimetry and small-angle X-ray scattering measurements. The triblocks were combined with up to 60 wt % of a renewable tackifier, and the resulting mixtures were evaluated using probe tack, 180° peel adhesion, and shear strength tests. Maximum values of peel adhesion (3.2 N cm−1) and tack (1.1 N) were obtained at 40 wt % of tackifier. These new materials hold promise as renewable and hydrolytically degradable pressure-sensitive adhesives.

Recent Progress in Sustainable Polymers Obtained from Cyclic Terpenes: Synthesis, Properties, and Application Potential

“…Later,anew method for preparing PLA-PM-PLA triblocks at 100 000 gmol À1 was reported by the same group. [84] In another study,H O-PM-OH was converted into bromo-terminated poly(menthide) (Br-PM-Br) by esterification with 2-bromoisobutyryl bromide,w hich was used as am acroinitiatorf or ATRP of methylene butyrolactone (MBL). Thus, four triblock copolymers of the type PMBL-PM-PMBL werep repared (Scheme 7B); [85] these are described by numberst hat refer to the molecular weights of the blocks (3-100-3, 5-100-5, 9-100-9,a nd 13-100-13).…”

Functionalization of soy fatty acid alkyl esters as bioplasticizers

“…After complete disappearance of the unsaturation proton peaks, the reaction mixture was washed several times with saturated sodium chloride solution and extracted with ethyl acetate three times, washed again with saturated sodium chloride solution, and dried over anhydrous Na 2 SO 4 . The solvent was evaporated by rotary evaporator to give N-tosylaziridine fatty acid methyl esters (8 Preparation of Unsaturated, N-tosylaziridine Fatty Acid Methyl Esters (9). To a stirred solution of soy fatty acid methyl esters (200 g, 1.05 mol) in acetonitrile (200 mL) under nitrogen atmosphere were added phenyltrimethyl ammonium tribromide (10 mol%) and anhydrous chloramine-T (120.5 g, 0.58 mol) sequentially.…”

“…The reaction mixture was washed several times with saturated sodium chloride solution and extracted with ethyl acetate (33 300 mL), finally washed again with saturated sodium chloride solution, and dried over anhydrous Na 2 SO 4 . The solvent was evaporated by rotary evaporator to give unsaturated, N-tosyl aziridine fatty acid methyl esters (9). …”

Synthesis of Terpene-Based Polymers

“…Renewable ABA triblock copolymers of (À)-menthide (B) and lactide (A) have been prepared by sequential ROPs aiming at the production of thermoplastic elastomers and pressure-sensitive adhesives [97][98][99]. Carvone is a monocyclic monoterpene vinyl ketone undergoing dimerization, but no polymerization, upon treatment with sodium amide.…”