Hydroxyl-containing thiol-alkene ethers and process of making and using same

Description (excerpt)

CROSS-REFERENCE TO RELATED APPLICATION The present application claims priority to U.S. Provisional Application Ser. No. 63/639,964 filed Apr. 29, 2024, the contents of which is hereby incorporated by reference in their entry. RIGHTS OF THE GOVERNMENT The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty. FIELD OF THE INVENTION The present invention relates to hydroxyl-containing thiol-alkene ethers and process of making and using same. BACKGROUND OF THE INVENTION Monomers are used to produce homopolymers and copolymers. Unfortunately, many current monomers are difficult to process as they are not as miscible as desired or they are solids. As a result, a new monomer that minimizes the drawbacks of current monomers was desired. Applicants recognized that in order to produce a stable monomer that had the desired characteristics, the monomer needed to be stabilized. Applicants recognized that the source of the stability problem was the excess reactivity of thiols with alkenes. Applicants solved this problem by adding a material that impeded the formation of thiol radicals. Applicants' monomers can be converted within seconds to polymeric materials by the addition of a radical initiator, heating and/or exposure to UV light. Polymers that are made from Applicants' monomers may be used to produce elastomers, adhesives and as resins for processes such as casting and 3D printing that are used to make articles. For example, 3-dimensional (3D) printing makes three-dimensional objects by building up material, based upon design data provided from a computer aided design (CAD) system. One technique is to deposit a crosslinkable material in a predetermined pattern, according to design data provided from a CAD system, with the build-up of multiple layers forming the object. The crosslinkable materials can be either in the form of filaments, powdered resins or liquid resins. When liquid resins are used as a raw material, the additive manufacturing processes that are used include direct ink writing and vat photopolymerization (VP)—examples of VP include but are not limited to techniques such as stereolithography (SLA), digital light processing (DLP), masked stereolithogrpahy (MSLA), and liquid crystal display (LCD) 3D printing. Unlike other resin materials, Applicants' resin monomer has a low viscosity. As a result, a diluent is not when required when Applicants' resin is used as resin for casting and 3D printing. Thus, articles that are made from Applicants' resins do not undergo dimensional and/or structural changes that occur when diluents are removed during final processing. Furthermore, most thiol containing resin materials have a negative reactivity and an objectionable odor. The higher molecular weight of Applicants' resin material minimizes both of such drawbacks. SUMMARY OF THE INVENTION The present invention relates to hydroxyl-containing thiol-alkene ethers and process of making and using same. Such monomers minimize the drawbacks of current monomers as they are highly miscible, stable and yet can be converted within seconds to polymeric materials by the addition of a radical initiator, heating and/or exposure to UV light. Polymers that are made from the disclosed monomers may be used to produce elastomers, adhesives and as resins for processes such as casting and 3D printing that are used to make articles. Furthermore, such monomers do not exhibit the objectionable odor that is normally associated with thiol containing resin materials and such monomers have a low viscosity so a diluent is not when required when a resin containing the disclosed monomers is used as resin for casting and 3D printing. As a result, articles that are made from such resins do not undergo dimensional and/or structural changes that occur when diluents are removed during final processing. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the summary given above, and the detailed description given below, serve to explain the invention. FIG. 1 is a process diagram depicting a process for producing a resin that can be cured into an article. It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic princip