Crosslinking Overview

Low surface energy plastics such as polyethylene (PE, HDPE, UHMWPE) and polypropylene (PP) are incredibly useful materials for applications that require molded dimensions, lightweight strength, durability, insulation or environmental resistance. Despite these material advantages, the resistance of low-surface energy plastics to adhesive forces has presented long-standing bonding challenging for designers and manufacturers.
Taking inspiration from the field of chemical biology, where diazirine chemistry has been employed for decades in small-molecule bonding applications, XlynX researchers were able to successfully overcome this challenge by applying a diazirine-based solution to a materials science context. Diazirines are three-member rings with one carbon and two double-bonded nitrogen atoms. On exposure to moderate heat, UV light or near UV-light (depending on application and XlynX compound), diazirines rapidly break down, expelling a molecule of nitrogen gas to form a highly reactive carbene which is capable of C-H, O-H, or N-H insertion bonds with nearly any nearby polymer substrate.
polymer drawing
polyethylene insertion
In doing so, polymer chains become joined in bonds known as crosslinking. The result of crosslinking the surface of a low surface energy polymer is an invisible layer of molecular bonds that improve the rigidity and mechanical properties of the polymer while also making it reactive to other adhesives, dyes and coatings. Because this new class of covalent molecular adhesive works through C-H insertion and not through surface-energy effects, the identity of the plastic substrates makes little difference. Strong adhesion can be obtained with various non-polar surface (like HDPE, UHMWPE, or polypropylene) as well as polar surfaces (like PMMA or polycarbonate). Bonding of dissimilar substrate surfaces (like HDPE-polypropylene junctions) can also be achieved.
The scientific, adhesive and material improvements at the core of XlynX’s products have been proven and peer-reviewed at the highest levels, and the results are easy to obtain through simple topical application and curing.

Make it stronger, with XlynX Materials.