XLYNX, a Canada-based specialist in polymer adhesion, has developed a fluorine-free primer for polypropylene (PP) and polyethylene (PE) that works with 15 leading adhesives, including epoxy, polyurethanes, and cyanoacrylate-types.
“Our original goal with redesigning PlastiLynx PXN was to eliminate fluorine, but the performance of this new primer has been a pleasant surprise,” a XLYNX spokesperson told Sustainable Plastics. “We ran head-to-head comparisons of the new PlastiLynx PXN crosslinker against the leading polyolefin primers on the market and were amazed by the difference. Not only did it perform better in apples-to-apples tests using the same adhesive (cyanoacrylate, an adhesive that most conventional primers must be used exclusively with), but PXN also works with any type of adhesive (like epoxies and polyurethanes). This means a much broader range of applications and dissimilar material bonding options are made available for manufacturers, including coatings and dyes,” the spokesperson explained.
XLYNK used its chemical crosslinking technology to develop PlastiLynx PXN, a polymeric diazirine primer which is free of per- and polyfluoroalkyl substances (PFAS), according to the company. The race to replace PFAS is driven by increasingly stringent regulations and standards regarding these ‘forever chemicals’, some of which have been shown to have harmful impacts on human health and the environment.
The Canadian materials company tested the performance of its new primer against two established brand name polyolefin primers. Results show that PlastiLynx PXN provided between 150% to 350% stronger adhesion to PP/PE substrate test (see graph below).
“These latest results really highlight how PlastiLynx PXN is in a class of its own compared to conventional polyolefin primers,” remarked Dr. Stefania Musolino, who led the XLYNX R&D team responsible for the new crosslinker. “Not only did we observe enhanced adhesion across the board, but we also saw strong compatibility with every type of bulk adhesive we tested.”
Commercial polyolefin primers are usually designed to work primary with cyanoacrylate-type adhesives, also known as ‘instant adhesives’ or ‘superglue’. PlastiLynx PXN, on the other hand, shows compatibility across 15 different leading adhesives, showing the best results with epoxy, polyurethanes, and cyanoacrylate-type adhesives.
“By being able to select the right adhesive for the job, manufacturers can choose from a variety of cost-effective adhesives that work with a much broader range of substrates and applications than ever before,” XLYNK said in a statement.
The product’s versatility is a result of the permanent covalent bonds it forms with the substrate surface, leaving a reactive amine layer that is receptive to adhesives, dyes, and coatings. Compared to traditional surface modification techniques for polyolefins like plasma and corona, PlastiLynx PXN was designed as a long-lasting treatment that remains active for months and does not damage the substrate surface. It is topically applied and cured rapidly with UV light or moderate heat.