The introduction of alkyl, ester, carboxylate, amino, hydroxyl, and phosphate functional groups to the surface of polyethylene

Abstract

SYNOPSISThe surface of polyethylene was derivatized with ester, carboxylate, amino, hydroxyl, and phosphate functional groups. 01, w bifunctional alkanes, containing on one end a primary amine, were coupled to oxidized polyethylene through an amide linkage. Polyethylene was first oxidized with chromic acid, the carboxylate groups were converted to the acyl chloride with phosphorus pentachloride, and then reacted with a primary amine to give the covalently bound amide. The copposing ends of the bifunctional alkanes were the methyl, tertiary amine, ester, and hydroxyl groups. The ester was converted to the carboxylate by acid cleavage and the hydroxyl group converted to the phosphate by treatment first with phosphorus oxychloride and then aqueous base. Attenuated total reflection FTIR, XPS, and pH-dependent contact angle wetting were used to characterize the surfaces. The FTIR data were used to confirm the formation of the amide and to detect an undesired carboxylatel ammonium ion complex formed in the presence of trace amounts of water. XPS data were used to confirm expected changes in elemental composition and to provide quantitative estimates of the yields. Oxidation of the polyethylene introduced 5 X 1014 carboxylate groups/cm* in the 25 A XPS sampling depth. Of these, up to 98% could be converted to the amide. The advancing contact angle data confirmed the acid/base behavior of the functional groups.

Surface-grafting of phosphates onto a polymer for potential biomimetic functionalization of biomaterials

“…Therefore the total number of grafted hydrophilic groups on PEAA-PA (phosphate) and PEAA-PS (carboxyl and phosphate) were similar at their highest grafting percentages. In several instances [32,33], it has been shown that phosphate groups are more hydrophilic than carboxylic acid group. One or two water molecules can form hydrogen bonds with a carboxyl group [34], whereas three or more water molecules can form hydrogen bonds with a phosphate group [35].…”

Sulfonation of low-density polyethylene and its impact on polymer properties

“…This study investigates an easily accessible, cost‐effective polymeric material with improved properties, which dissipates static charge and renders the material more susceptible to common dyestuff, while retaining the essential mechanical properties of low‐density polyethylene for its intended use in technical textiles . Polyolefins films have been treated with mineral acids under different reaction conditions in order to achieve a rough film surface and to introduce polar groups . Common polyolefin are used in the packaging industry and most of the research work reported in the literature is related to only chemical surface treatment of films .…”

Effect of surface oxidation treatments on DC charge injection into polyethylene from aqueous electrolytes

“…XPS measurements, also referred to in the literature as ESCA (electron spectroscopy for chemical analysis), have been performed on polyethylene by a variety of authors [4,[5][6][7]24], employing a variety of surface treatments including exposure to corona discharge, plasma etching, and electrochemical exposure (oxidizing electrolytes). Oxidation products could be detected by two different measurement systems: presence of the O1s binding energy, or higher energy shoulder on the C1s binding energy curve, indicating a change in bonding environment for the carbon atoms [7].…”