Properties of shape memory polyurethane used as a low-temperature thermoplastic biomedical orthotic material: Influence of hard segment content

Qinghao Meng, Jinlian Hu, Yong Zhu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

24 Citations (Scopus)


A series of PCL-based shape memory polyurethanes was synthesized via bulk pre-polymerization. Their thermal, mechanical properties, shape memory properties, softening and hardening processes were investigated by the experimental approach and made comparison with a commercially available orthotic material. The cytotoxicity of the low-temperature thermoplastic polyurethane was tested. The results suggest that the soft segment phase of the shape memory polyurethanes has a melting transition at about 36-46°C, which makes them possible low-temperature thermoplastic materials. The hard segment phase has a two-fold effect on the shape memory polyurethane as a low-temperature thermoplastic orthotic material: increasing tensile mechanical strength at room temperature, which enables it to be used in circumstances where high tensile strength is required; and reducing low-temperature malleability and fixity ratio, which make it difficult to fabricate orthortic devices. To obtain a shape memory polyurethane with excellent low-temperature thermoplastic properties for orthopaedical surgical use, the hard segment content should not be above 22 wt%. At last, a prototype wrist orthosis was easily fabricated at 60°C with hand using a shape memory polyurethane with 16 wt% hard segment content. Cytotoxicity tests indicate that the wrist orthotic material is not cytotoxic.
Original languageEnglish
Pages (from-to)1437-1454
Number of pages18
JournalJournal of Biomaterials Science, Polymer Edition
Issue number11
Publication statusPublished - 1 Nov 2008


  • Low-themperature thermoplastic
  • Orthotic material
  • Shape memory polyurethane

ASJC Scopus subject areas

  • Biophysics
  • Bioengineering
  • Biomaterials
  • Biomedical Engineering

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