Methods for polymerizing films in-situ using a radiation source

A method for formation of a polyurethane-based polymer film in-situ, the method comprising steps of:

• providing a polymerizable composition in one or multiple parts, wherein the polymerizable composition is essentially non-polymerized and comprises at least an isocyanate-functional component and an isocyanate-reactive component that are mutually reactive with each other via chemically different reactive moieties to form a polyurethane-based polymeric backbone where at least 80% urethane and/or urea repeat linkages in the polyurethane-based polymeric backbone are subsequently formed after polymerization of the polymerizable composition is initiated;
• positioning the polymerizable composition into a desired film format,
• initiating polymerization of the polymerizable composition using a radiation source just before, while, or shortly after the polymerizable composition is being positioned into the desired film format to form the polyurethane-based polymer film;
• and
• essentially completing polymerization during such positioning or shortly thereafter,
• wherein the polyurethane-based polymer film is formed prior to completion of polymerization of the polymerizable composition,
• wherein the polyurethane-based polymer film is based on polymers having a polymeric backbone where at least 80% urethane and/or urea repeat linkages are formed during polymerization of the polymerizable composition to form the polyurethane-based polymer film, and
• wherein the polymer film can be physically separated from a supporting substrate on which the polymer film is formed.