Chemical Modification of a Poly(ethylene terephthalate) Surface by the Selective Alkylation of Acid Salts

Abstract

Chemical modification of the hydrophilic surface of poly(ethylene terephthalate) (PET) was examined by the selective alkylation of the acid salt on the surface using acyl bromides as an electrophile with catalytic potassium fluoride. The hydrophobicity of the PET surface increased as the alkylation reaction of the hydrolyzed surface proceeded. The chemical incorporation of the alkylation reagents was confirmed by the presence of fluorine peaks in X‐ray photoelectron spectroscopy (XPS) from the fluorinated reagents. Exponential increases were observed in the emission and excitation intensities of fluorescence spectra during the reaction of the surface with a fluorescent reagent. This indicated that the esterification of carboxylic acids on the surface proceeded without deterioration of the reaction even at the later stages. The relation between changes in contact angles and the fluorescence spectra revealed that the hydrophobicity of a surface was quickly restored at the beginning of a reaction. magnified image

Highly efficient interpenetrating polymerization of styrene and 4-vinylpyridine with poly(ethylene terephthalate) using benzoyl peroxide

“…). After KOH hydrolysis, the contact angle of PET surface decreases from 85° to 75°, consistent with previous literature . Then the KOH‐treated PET samples were immobilized with styrene using the following conditions: a monomer‐to‐initiator molar ratio of 466, temperature of 100 °C and reaction time of 2 h. After polymerization with styrene, the immobilization percentage is 58%, close to the 56% when using non‐KOH‐treated PET.…”

“…The effect of the hydrophilicity of PET surface was studied. Using a standard procedure, the PET samples were treated with potassium hydroxide (KOH) solution (1 mol L −1 ) at 85 °C for 90 min in order to partially hydrolyse the ester groups in the PET chains into hydroxyl and carboxyl groups (Fig. ).…”

“…In order to increase the hydrophilicity of the PET surface, cleaned PET samples were heated in 1 mol L −1 potassium hydroxide solution at 80 °C for 90 min. Then the PET samples were ultrasonicated in deionized water three times (10 min each) and rinsed with acetone.…”

Postpolymerization modification of polynorbornene side chains via tetramethyl guanidine promoted esterification

“…Acids are barely used for functionalization of activated bromides since the nucleophilicity of carboxylates is relatively weak. For example, nucleophilic substitutions between activated bromides and acids in the presence of potassium fluoride are reported, but high temperature and prolonged reaction time are basically required. Indeed, the esterification efficiency is far from satisfactory if common bases are selected as catalysts .…”

Tailoring Thermoplastic In-Plane Nanopore Size by Thermal Fusion Bonding for the Analysis of Single Molecules

“…The transport properties of biomolecules through nanopores depend on interactions of analytes with the nanopore’s surface. , Several reports have discussed the functionalization of pore surfaces to facilitate transport or other properties. For example, Martin et al reported a method to alter the surface properties of track-etched nanopores in polycarbonate with gold by electroless deposition followed by chemisorption of thiols. , For polyimide (PI) and polyethylene terephthalate (PET), the surface carboxyl groups created during track etching were chemically functionalized with an alkyl bromide and KF catalyst, − methylation, or amidation. , Previously, our group reported surface modification of PMMA nanochannels to generate both negatively charged and positively charged surfaces . A negatively charged surface was generated via O 2 plasma treatment, which forms carboxyl groups on the thermoplastic surface.…”