Improved adhesion in elastomeric laminates using elastomer blends

ABSTRACT Interlayer adhesion between distinct rubber compositions in elastomeric laminates has been pursued by a variety of approaches, including treating surfaces, introducing assistant chemicals, and interposing a “transition layer.” Each approach, however, may be specific to the elastomer chemistries and may not be easily transferred to other rubber composition pairs in laminates. These limitations were overcome by inserting a layer at the interface that is a blend of each of the elastomer compositions of the adjacent layers and that increases the interfacial adhesion strength of the resultant laminates. This approach was demonstrated using three elastomer systems: fluoroelastomer (FKM), acrylonitrile–butadiene rubber (NBR), and isobutylene–isoprene rubber (IIR). The adhesion in the three-layer laminate (FKM/NBR/IIR) was improved with the addition of an FKM-NBR blend layer between the FKM and NBR layers and the addition of an NBR-IIR blend layer between the NBR and IIR layers. The five-layer laminate (FKM/[FKM-NBR blend]/NBR/[NBR-IIR blend]/IIR) was also fabricated. Interfacial adhesion was evaluated using the T-peel test according to ASTM D1876, which showed that the blends provided improved adhesion. Scanning electron microscope images were used to study the interface region. The proposed idea offers a general approach to improve interfacial strength that is widely applicable to other multilayer elastomer laminates.