Sulfonation and Characterization of Tert-Butyl Styrene/Styrene/Isoprene Copolymer and Polypropylene Blends for Blood Compatibility Applications

Abstract

Hydrogenated styrenic block copolymers (HSBCs) have been used in medical tubing for many years due to their high clarity, flexibility, kink resistance, and toughness. However, when it comes to blood storage applications, HSBC compounds’ market has been limited because of their high hydrophobicity, which may trigger platelet adhesion when contacting with blood. HSBC needs to be physically or chemically modified in advance to make it blood compatible; however, HSBC has strong UV/ozone resistance, thermooxidative stability, and excellent processing capability, which increases the difficulty of the chemical modification process as unsaturated dienes has been converted to saturated stable midblocks. Moreover, medical HSBC-containing compounds primarily make up with the non-polar, hydrophobic nature and benign characteristics of other common ingredients (U.S. Pharmacopeia (USP) grades of mineral oil and polypropylene), which complicates the realization of using HSBC-containing compounds in blood-contacting applications, and this explains why few studies had disclosed chemical modification for biocompatibility improvement on HSBC-containing compounds. Sulfonation has been reported as an effective way to improve the material’s blood/platelet compatibility. In this study, hydrogenated tert-butyl styrene (tBS)-styrene-isoprene block copolymers were synthesized and its blends with polypropylene and USP grades of mineral oil were selectively sulfonated by reaction with acetyl sulfate. By controlling the ratio of the hydrogenated tBS-styrene-isoprene block copolymer in the blend, sulfonated films were optimized to demonstrate sufficient physical integrity in water as well as thermal stability, hydrophilicity, and platelet compatibility.

Strong Antimicrobial Activity of Highly Stable Nanocomposite Containing AgNPs Based on Water-Soluble Triazole-Sulfonate Copolymer

“…Along with triazole fragments, negatively charged sulfonate groups are introduced into macromolecules, which contribute to an increase in the number of coordination centers of metal nanoparticles and a significant increase in the stabilizing ability of the copolymer. At the same time, the spectrum of useful properties of the polymer matrix is expanding, since it is known that blood-compatible drug carriers, which reduce protein absorption and platelet adhesion, as well as drug delivery systems have been developed on the basis of polyvinyl sulfonic acid [34][35][36][37][38][39][40].…”

Studies of the Sulfonated Hydrogenated Styrene–Isoprene–Styrene Block Copolymer and Its Surface Properties, Cytotoxicity, and Platelet-Contacting Characteristics

“…In our previous work, we found that the sulfonation of blends of polypropylene/ tert -butyl SEPS demonstrated physical stability as well as biocompatible performance in terms of mechanical intactness, low platelet adhesion, and being free of cytotoxicity [ 20 ]. We also observed that the mechanical property of blends of sulfonated PP/ tert -butyl SEPS with different mixing ratios was brittle, and the brittleness of blends of sulfonated PP/ tert -butyl SEPS film can be reduced dramatically with the aid of mineral oil as an additional plasticizer.…”