Surface functionalization of polyethylene via covalent immobilization of O-stearoyl-chitosan

• Published in: Applied surface science Vol. 279; pp. 424 - 431
• Main Authors: Xin, Zhirong, Hou, Juan, Ding, Jiaotong, Yang, Zongfeng, Yan, Shunjie, Liu, Chan
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.08.2013; Elsevier
• Subjects: Anti-platelet adhesion; Chitosan; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Density; Exact sciences and technology; Grafting; Immobilization; O-stearoyl-chitosan (OSC); Photo-grafting polymerization; Physics; Plasma pre-treatment; Polyethylene (PE); Polyethylenes; Polymerization; Strength; X-ray photoelectron spectroscopy; O-stearoyl-chitosan (OSC); Photo-grafting polymerization; Plasma pre-treatment; Polyethylene (PE); Anti-platelet adhesion; Plasma assisted processing; Polymerization; Adhesion
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2013.04.131

•O-stearoyl-chitosans (OSC) with a reduced cationic strength was obtained.•The PAA-grafted PE film was prepared by photografting of acrylic acid.•The covalent immobilization of OSC onto a PE substrate was obtained.•The OSC-immobilized sample had excellent anti-adhesion of platelet. When used in blood-contacting field, the hemocompatibility of polyethylene (PE) needs further to be improved. In this article, O-stearoyl-chitosans (OSC) with different esterification degrees were successfully prepared via changing the ratios of chitosan and stearoyl chloride for decreasing the cationic and hydrogen bond strength, thus improving the solubility of chitosan. The PE film was grafted with carboxyl groups of acrylic acid (AA) (PE-g-PAA) by means of O2 plasma pre-treatment and UV-induced graft polymerization, and then PE-g-PAA was used for covalent immobilization of OSC. The above surface modification was confirmed by ATR-FTIR and XPS. Effect of the UV-irradiated graft polymerization parameters, i.e., the discharge power, the plasma pretreatment time, the UV irradiation time and the monomer concentration on the grafting density of AA was investigated. Relative to the value of about 107° for the virgin sample, the water contact angle (WCA) of the PAA-grafted film was about 50°. After the further immobilization of OSC onto the PAA-grafted film, the strength of negative charge of the PAA-grafted surface was decreased by the electropositive OSC, thus presenting a WCA value of about 62° and the excellent performance of anti-platelet adhesion with respect to the virgin and PAA-grafted samples.