Plasma Enhanced-Chemical Vapor Deposition of 2-Isopropenyl-2-Oxazoline to Promote the Adhesion between a Polyethylene Terephthalate Monofilament and the Rubber in a Tire

Carlo Maria Gaifami,Claudia Riccardi,Luca Zoia,Stefano Zanini

doi:10.3390/coatings11060708

Carlo Maria Gaifami, Claudia Riccardi + Show 2 more

Open Access

https://doi.org/10.3390/coatings11060708

Copy DOI

Journal: Coatings	Publication Date: Jun 12, 2021
Citations: 2	License type: CC BY 4.0

Affiliation: University of Milano-Bicocca

Abstract

A Plasma-Enhanced Chemical Vapor Deposition was chosen in order to deposit an organic thin film on polyethylene terephthalate monofilament to increase its adhesion with the rubber compound in a tire. The aim of the work is to find an alternative “green” method to the classical chemical dipping with Resorcinol Formaldehyde Latex: plasma treatments are environmentally friendly and easy to use. 2-isoprepenyl-2-oxazoline (2-iox) was employed as precursor and the treatments were performed in a vacuum system, both in a continuous regime and a pulsed regime. Initially, the coatings were deposited on polyethylene terephthalate sheets to study the wettability (by the measurement of contact angle) and the thickness (by profilometer) of the plasma polymer. The chemical characterization was investigated by Infrared and X-ray Photoelectron spectroscopies. Finally, the adhesion of the polyethylene terephthalate sheets was measured by Peel Test, using the coating as adhesive and as a pre-dip. The measurement of the peel force made it possible to optimize the plasma parameters that were applied on the monofilament. The adhesion was estimated by the measure of the extraction force and the evaluation of the coverage compared with those of the classical chemical treatment Resorcinol Formaldehyde Latex.

Highlights

Tire is a composite material, where man-made organic fibers are employed to reinforce the rubber compound; in the tire industry, the most used organic fibers are Rayon, Polyamide 6/6.6, Polyethylene terephthalate (PET) and Aramid
The adhesion between the organic textile reinforcing materials and the rubber is a crucial aspect to guarantee the tire integrity and durability: from the 1940s to the present, the adhesion was made possible by the Resorcinol Formaldehyde Latex (RFL)
Different approaches from different authors were recently explored: one strategy was the preparation of formaldehyde-free adhesive using acrylic resin, another strategy was chemical etching with bromine or the insertion of blocked isocyanate in the compound to promote adhesion [7,8,9]

Summary

Introduction

Tire is a composite material, where man-made organic fibers are employed to reinforce the rubber compound; in the tire industry, the most used organic fibers are Rayon (regenerated cellulose), Polyamide 6/6.6, Polyethylene terephthalate (PET) and Aramid (aromatic polyamide). Different approaches from different authors were recently explored: one strategy was the preparation of formaldehyde-free adhesive using acrylic resin, another strategy was chemical etching with bromine or the insertion of blocked isocyanate in the compound to promote adhesion [7,8,9]. In this view, plasma technology is an increasingly promising technique. “The General Tire & Rubber Company” patented a plasma activation followed by a grafting with vinyl pyridine before dipping in the RFL, to improve the adhesion of Aramid cord [11]. Another plasma approach was explored by Mzabi et al and based on PE-CVD

Objectives

Methods

Results

Conclusion