Synthesis of urea-containing ABA triblock copolymers: Influence of pendant hydrogen bonding on morphology and thermomechanical properties

Mingtao Chen, David L. Inglefield, Keren Zhang, Amanda G. Hudson, Samantha J. Talley, Robert B. Moore, Timothy Edward Long

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Reversible addition-fragmentation chain transfer (RAFT) polymerization produced novel ABA triblock copolymers with associative urea sites within pendant groups in the external hard blocks. The ABA triblock copolymers served as models to study the influence of pendant hydrogen bonding on polymer physical properties and morphology. The triblock copolymers consisted of a soft central block of poly(di(ethylene glycol) methyl ether methacrylate) (polyDEGMEMA, 58 kg/mol) and hard copolymer external blocks of poly(2-(3-hexylureido)ethyl methacrylate-co-2-(3-phenylureido)ethyl methacrylate) (polyUrMA, 18-116 kg/mol). Copolymerization of 2-(3-hexylureido)ethyl methacrylate (HUrMA) and 2-(3-phenylureido)ethyl methacrylate (PhUrMA) imparted tunable hard block Tg's from 69 to 134 °C. Tunable hard block Tg's afforded versatile thermomechanical properties for diverse applications. Dynamic mechanical analysis (DMA) of the triblock copolymers exhibited high modulus plateau regions (∼100 MPa) over a wide temperature range (−10 to 90 °C), which was indicative of microphase separation. Atomic force microscopy (AFM) confirmed surface microphase separation with various morphologies. Variable temperature FTIR (VT-FTIR) revealed the presence of both monodentate and bidentate hydrogen bonding, and pendant hydrogen bonding remained as an ordered structure to higher than expected temperatures. This study presents a fundamental understanding of the influence of hydrogen bonding on polymer physical properties and reveals the response of pendant urea hydrogen bonding as a function of temperature as compared to main chain polyureas.

Original languageEnglish
Pages (from-to)1844-1852
Number of pages9
JournalJournal of Polymer Science, Part A: Polymer Chemistry
Volume56
Issue number16
DOIs
Publication statusPublished - 2018 Aug 15
Externally publishedYes

Keywords

  • block copolymers
  • hydrogen bonding dissociation
  • morphology
  • reversible addition-fragmentation chain transfer polymerization
  • urea

ASJC Scopus subject areas

  • Polymers and Plastics
  • Organic Chemistry
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Synthesis of urea-containing ABA triblock copolymers: Influence of pendant hydrogen bonding on morphology and thermomechanical properties'. Together they form a unique fingerprint.

  • Cite this