Novel hard-block polyurethanes with high strength and transparency for biomedical applications

Area of Science:

• Polymer Science
• Materials Science
• Biomaterials Engineering

Background:

• Polyurethanes are versatile polymers with applications in various fields.
• Developing polyurethanes with enhanced properties for biomedical use remains an active research area.
• Incorporating siloxane segments can modify polyurethane characteristics.

Purpose of the Study:

• To synthesize novel hard-block-only polyurethanes using specific monomers.
• To evaluate the microstructure, mechanical properties, and oxidative biostability of these new polyurethanes.
• To explore the potential of these materials for biomedical applications.

Main Methods:

• Synthesis of a pre-polymer from 1,3-bis(4-hydroxybutyl) tetramethyl disiloxane (BHTD) and 4,4'-diphenylmethane diisocyanate (MDI).
• Preparation of (co)polymers using reaction injection moulding with varying proportions of BDO and BHTD.
• Characterization of microstructure, mechanical properties (elastic modulus, tensile strength, ductility), and in vitro oxidative biostability.

Main Results:

• The synthesized polyurethanes formed a single-phase system and exhibited optical transparency.
• Materials demonstrated high elastic modulus, tensile strength, and significant in vitro oxidative biostability.
• Ductility was tunable over orders of magnitude by adjusting the BDO/BHTD composition.

Conclusions:

• Novel hard-block-only polyurethanes with tunable mechanical properties were successfully prepared.
• These polyurethanes possess desirable characteristics for biomedical applications.
• Potential uses include electronic headers for implantable devices and orthopedic encapsulation.