Structure-property-glass transition relationships in non-isocyanate polyurethanes investigated by dynamic nanoindentation

Newly developed green-chemistry approaches towards the synthesis of non-isocyanate polyurethane (NIPU) systems represent a promising alternative to polyurethanes (PU) eliminating the need for harmful ingredients. A series of NIPU systems were studied using different nanoindentation techniques in ord...

Full description

Saved in:
Bibliographic Details
Published in:Materials research express 2016-07, Vol.3 (7), p.75019
Main Authors: Weyand, Stephan, Blattmann, Hannes, Schimpf, Vitalij, Mülhaupt, Rolf, Schwaiger, Ruth
Format: Article
Language:English
Subjects:
bio-based
dynamic nanoindentation
NIPU
non-isocyanate polyurethane
stiffening
structure-property relationship
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Newly developed green-chemistry approaches towards the synthesis of non-isocyanate polyurethane (NIPU) systems represent a promising alternative to polyurethanes (PU) eliminating the need for harmful ingredients. A series of NIPU systems were studied using different nanoindentation techniques in order to understand the influence of molecular parameters on the mechanical behavior. Nanoindentation revealed a unique characteristic feature of those materials, i.e. stiffening with increasing deformation. It is argued that the origin of this observed stiffening is a consequence of the thermodynamic state of the polymer network, the molecular characteristics of the chemical building blocks and resulting anisotropic elastic response of the network structure. Flat-punch nanoindentation was applied in order to characterize the constitutive viscoelastic nature of the materials. The complex modulus shows distinct changes as a function of the NIPU network topology illustrating the influence of the chemical building blocks. The reproducibility of the data indicates that the materials are homogeneous over the volumes sampled by nanoindentation. Our study demonstrates that nanoindentation is very well-suited to investigate the molecular characteristics of NIPU materials that cannot be quantified in conventional experiments. Moreover, the technique provides insight into the functional significance of complex molecular architectures thereby supporting the development of NIPU materials with tailored properties.
ISSN:2053-1591
2053-1591
DOI:10.1088/2053-1591/3/7/075019