Digital Light Processing (DLP) 3D Printing of Caprolactone Copolymers with Tailored Properties through Crystallinity

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomaterials Engineering

Background:

• Digital Light Processing (DLP) 3D printing offers high resolution but requires photocurable materials with tunable properties.
• Existing photocurable materials often need post-functionalization, limiting fabrication efficiency.

Purpose of the Study:

• To synthesize and characterize novel poly(caprolactone) copolymers for DLP 3D printing with built-in thiol-ene functionality.
• To investigate the photocuring behavior, thermal properties, mechanical properties, and shape memory effects of these copolymers.

Main Methods:

• Synthesis of crystalline block and amorphous statistical copolymers of caprolactone and allyl caprolactone.
• Thiol-ene photocuring with a tetrafunctional thiol cross-linker at varying ratios.
• Characterization of thermal properties (DSC), mechanical properties (modulus), and shape memory behavior.
• Fabrication of 3D scaffolds using DLP printing.

Main Results:

• Copolymers exhibited rapid photocuring within seconds.
• Block copolymer networks showed significantly higher modulus (31x) compared to statistical copolymers due to crystallinity.
• Thermal properties and mechanical strength were tunable by adjusting block copolymer content and blending.
• DLP-printed scaffolds demonstrated shape memory properties, a first for PCL copolymers in DLP.

Conclusions:

• Novel PCL copolymers with built-in thiol-ene functionality enable efficient DLP 3D printing.
• Crystallinity is a key factor in tailoring mechanical properties of 3D printed PCL-based materials.
• These materials offer a versatile platform for creating degradable, cell-compatible biomaterials with tunable properties and shape memory capabilities.