Benzoxazine + BMI?

Resin supplier Huntsman Advanced Materials (Basel, Switzerland and The Woodlands, Texas) sees benzoxazine resins as traditional chemistry boundary breakers that open whole new resin-system possibilities. For example, a recent patent application describes novel benzoxazine/thiol compositions that are useful in coatings, sealants, adhesives and many other applications.

“Traditionally, this cannot be achieved with epoxy,” explains Huntsman scientist technologist Dong Wang. “This shows how benzoxazine’s chemistry is overcoming obstacles in polymer formulation and processing.”

Recently, in fact, there has been a flurry of research activity on blends of bismaleimide (BMI) and benzoxazine, including a 2013 Chinese patent application specifically for composites applications that claims the blend exhibits improved thermal stability and toughness vs. benzoxazine alone, yet it maintains the inherent machinability of the latter.

“The ability to achieve truly unique resin properties is practically limitless,” claims Wang, “because not only can benzoxazine react with so many polymers but there is such a wide variety of amine and phenol monomers which can also be combined and tailored to affect the final system performance.” Researchers in India, for example, report modifying benzoxazine’s T_g by 149°C/88°F simply by playing with the monomer feed ratio.

Huntsman predicts that such custom tailoring of resins will be the norm in structural composites within 15 to 20 years.