Sustainable high molecular weight copolymers using the Vandenberg catalyst

This technology creates high molecular weight copolymers from lactones and epoxides using the Vandenberg catalyst. The process produces versatile, biodegradable materials with unique thermal properties and potential applications in environmental and biomedical fields.

Background

Copolymerization of lactones and epoxides is a crucial area of research in polymer chemistry due to its potential to create materials with tailored properties for applications such as biocompatible scaffolds and environmentally friendly plastics. But the copolymerization of structurally distinct monomers such as lactones and epoxides presents significant challenges, due to their differing reactivity and polymerization mechanisms.

Traditional copolymerization techniques that are limited to structurally homologous monomers (pure (meth)acrylate or epoxide) can be polymerized more predictably. However, the disparity in ring strain between epoxides and lactones, along with their differing affinities for propagation centers, complicates the synthesis of high molecular weight copolymers with desired properties. Previous attempts at copolymerizing these monomers have often resulted in block or multiblock architectures rather than true statistical copolymers. Also, achieving the simultaneous copolymerization of monomers with such distinct characteristics needs a catalyst that can facilitate both homopolymerization and copolymerization in a controlled manner.

Existing methods have problems like incomplete monomer conversion, broad molecular weight distributions, and difficulty in determining accurate reactivity ratios, particularly for systems involving reversible polymerization equilibria. These challenges highlight the need for innovative approaches to enable the direct statistical copolymerization of lactones and epoxides, thereby expanding the scope and versatility of copolymerization techniques in creating multifunctional polymeric materials.

Technology description

This technology details the synthesis and characterization of high molecular weight copolymers composed of lactones and epoxides using the Vandenberg catalyst. The copolymers are formed from monomer pairs including DL-lactide, ε-caprolactone, and various epoxides (e.g., epichlorohydrin, butylene oxide, propylene oxide, and ethylene oxide). The process involves mixing the monomers and initiating polymerization with the Vandenberg catalyst.

The resulting copolymers exhibit high molecular weights and display distinct signals in their spectra. Reactivity ratios were determined, indicating a gradient copolymer structure. Thermal properties of the copolymers differ from their respective homopolymers, and the copolymers demonstrate expected hydrolytic degradability under neutral and basic conditions.

This technology is differentiated by its ability to copolymerize structurally distinct monomers—lactones and epoxides—into high molecular weight statistical copolymers, which is not commonly achievable with traditional copolymerization methods. The use of the Vandenberg catalyst, originally developed for epoxide polymerization, allows for the creation of copolymers with unique thermal and mechanical properties. The distinct ester-ether dyad signals in its spectra confirm the successful incorporation of both monomer types into the polymer backbone. Additionally, the hydrolytic degradability of the copolymers makes them suitable for environmental and biomedical applications, providing a versatile platform for designing functional polymeric materials from readily available and structurally diverse precursors.