NEWS

To improve the wear resistance of biaxially oriented polypropylene membrane (BOPP membrane), a novel polypropylene surface modification coating with good transparency and wear resistance was prepared by sol-gel method, using silane coupling agent (KH550), aluminum sec butanol (ASB) and ethyl orthosilicate (TEOS) as precursors, solid acid (p-toluene sulfonic acid) as catalyst, and water in the air as the source of hydrolysis; In order to improve the binding property between the surface modification coating and biaxial oriented polypropylene film, potassium permanganate (KMnO4)/sulfuric acid (H2SO4) solution was used as oxidant and oxalic acid as cleaning agent to pretreat the surface of biaxial oriented polypropylene film; On this basis, the BOPP film pretreated by potassium permanganate and the developed surface modification coating were compounded to prepare the biaxially oriented polypropylene film with high wear resistance by dipping and pulling method.

First of all, by optimizing the preparation process, the surface modification coating with uniform particle size and average particle size of about 30 nm was prepared in situ. Infrared spectrum analysis showed that Si-O-Al covalent bond was formed in the prepared modified coating; The transmittance analysis found that the aluminum sol can effectively inhibit the whitening phenomenon caused by the massive cross-linking and agglomeration of the silica sol, which shows that the surface modification coating can make the modified film maintain the excellent optical properties of the original BOPP film.

Secondly, through the surface pretreatment of BOPP film, polar groups such as COOH and - OH were successfully introduced on the surface of BOPP film, which significantly increased the surface free energy by 28.1%, which provided a good basis for improving the interfacial bonding ability between BOPP film and the coating formed by surface modification coating.