Interfacial reaction of a maleic anhydride grafted polyolefin with ethylene vinyl alcohol copolymer at the buried solid/solid interface

Abstract

In this research, sum frequency generation (SFG) vibrational spectroscopy, a surface and interface specific technique, was used to study chemical interactions occurring at the buried interface between two polymers in situ. More specifically, the chemical reaction at the buried poly (ethylene vinyl alcohol) (EVOH)/maleic anhydride (MAH) grafted polyethylene (MAHgEO) interface was monitored at the molecular level using SFG. This system was compared to a control EVOH/polyethylene (EO) (without MAH) system where no chemical reaction was observed at the interface. Results from the hydroxyl and carbonyl stretching regions contain contributions from the reaction products of EVOH with MAHgEO. SFG results suggest a chemical reaction occurs which increases interlayer adhesion, consistent with adhesion measurements. This work demonstrates that chemical reactions at buried interfaces between two polymers can be probed in situ nondestructively by SFG, and such interfacial reactions are important for the development of designed polymer/polymer interfaces with improved functionality and properties.