Effects of Kinetic Chain Length on the Degradation of Poly(β-amino ester)-Based Networks and Use in 3D Printing by Projection Microstereolithography

Biomacromolecules. 2022 Aug 8;23(8):3272-3285. doi: 10.1021/acs.biomac.2c00362. Epub 2022 Jul 6.

Abstract

Poly(β-amino ester)-diacrylates (PBAE-dAs) are promising resins for three-dimensional (3D) printing. This study investigated the degradation of two PBAEs with different chemistries and kinetic chain lengths. PBAE-dA monomers were synthesized from benzhydrazide and poly(ethylene glycol) (A6) or butanediol (B6) diacrylate and then photopolymerized with pentaerythritol tetrakis(3-mercaptopropionate), which formed thiol-polyacrylate kinetic chains. This tetrathiol acts as a cross-linker and chain-transfer agent that controls the polyacrylate kinetic chain length. A6 networks exhibited bulk degradation, while B6 networks exhibited surface degradation, which transitioned to a combined surface and bulk degradation. Increasing the tetrathiol concentration shortened the polyacrylate kinetic chain and time-to-reverse gelation but degradation mode was unaffected. Hydrolysis occurred primarily through the β-amino ester. As network hydrophilicity increased, the slower degrading ester in the thiol-polyacrylate chains contributed to degradation. Overall, this work demonstrates control over network degradation rate, mode of degradation, and time-to-reverse gelation in PBAE networks and their application in 3D printing.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Esters*
  • Polyethylene Glycols
  • Polymers* / pharmacology
  • Printing, Three-Dimensional
  • Sulfhydryl Compounds

Substances

  • Esters
  • Polymers
  • Sulfhydryl Compounds
  • poly(beta-amino ester)
  • Polyethylene Glycols