Crosslinking Overview

Low surface energy plastics such as polyethylene (PE, HDPE, UHMWPE) and polypropylene (PP) are remarkable materials for applications that require molded dimensions, lightweight strength, durability, or resistant properties. Despite these advantages, low-surface energy plastics present challenges to designers and manufacturers because of their resistance to bonding with other materials, coatings or dyes.

Drawing on inspiration from the field of chemical biology, XLYNX researchers overcame this  bonding challenge by successfully applying a diazirine crosslinking solution to a materials science context. Diazirines are three-member rings with one carbon and two double-bonded nitrogen atoms. When to moderate heat, UV light or near UV-light, diazirines rapidly break down, expelling a molecule of nitrogen gas to form a highly reactive carbene which is capable of forming C-H, O-H, or N-H insertion bonds with nearly any nearby polymer substrate.

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 science at the core of XLYNX’s products have been proven and peer-reviewed at the highest levels, and the adhesive and material improvements require only topical application and curing to achieve. Discover how crosslinking technology can resolve your design and manufacturing challenges.

Diazirine crosslinkers form bonds across polymer chains
Diazirine crosslinkers form bonds across polymer chains, adding strength, stability, and adhesion.

Make it stronger, with XLYNX Materials