Cross-Linkers for Improved High Temperature Performance of ROMP Adhesives

✍ Scribed by Christopher G. Keck; Jonathan L. Kendall; Kenneth C. Caster

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 295 KB
• Volume: 349
• Category: Article
• ISSN: 1615-4150
• DOI: 10.1002/adsc.200600455

✦ Synopsis

Abstract

Ring‐opening metathesis polymerization (ROMP) has been shown to be an effective methodology to make adhesive bonds between various substrates. Excellent adhesion has been demonstrated on a variety of substrates including post‐vulcanized elastomers, polyolefins, and metals. Strong adhesion results when one substrate surface is coated with the metathesis catalyst and the other substrate surface is coated with a ROMPable monomer. Concerns over using ROMP‐based adhesion in dynamic applications where the bond‐line could experience higher‐than‐ambient temperatures prompted this investigation. In this report, a variety of bis‐norbornadiene cross‐linkers were used to bond tire carcass, tire tread, post‐vulcanized EPDM, and grit‐blasted steel in a variety of self‐ and cross‐bonded configurations. The resulting bonded assemblies were then evaluated using a 180° peel test in a temperature range from −40 °C to 66 °C at various cross‐linker concentrations. Significant improvements in bond strength were observed at elevated temperature with little detrimental affect on low temperature strengths even at high cross‐linker concentration. Self‐bonding of polyolefins assemblies was also investigated. Addition of a peroxide radical initiator to the initial ROMP formulation and cross‐linking the bonded assembly in a post‐cure reaction was also found to lead to improved high temperature bond strength. Synthetic details for the preparation of several cross‐linkers are reported.