TY - JOUR
T1 - Cooperative principle in multiple glass transitions and strain relaxations of thermochemically responsive shape memory polymer
AU - Wang, Xiaodong
AU - Lu, Haibao
AU - Wu, Nan
AU - Hui, David
AU - Chen, Mingji
AU - Fu, Yong Qing (Richard)
PY - 2019/8/1
Y1 - 2019/8/1
N2 - Cooperative principle in shape memory polymers (SMPs) result in their effective communication with the external thermochemical stimuli and then the SMPs act cooperatively to generate stimulus-responsive shape memory effect (SME). Their SME can be triggered by chemical stimuli and the corresponding thermochemically responsive behaviors are often explained by the reversible rearrangement of macromolecule segments due to changes of their configurational entropy. In this paper, we propose a new cooperative model to describe the multiple glass transitions and strain relaxations of an SMP in response to the water by means of selective and chemical plasticization effect on the partial segments in a macromolecule. Based on this model, the plasticization effect on the glass transition temperature, relaxation time and recovery strain of the SMP have been systematically investigated. Finally, the constitutive model for thermochemically responsive SMPs with two viscoelastic transitions and multiple SMEs was established to describe their overall mechanical responses, and a good agreement between the numerical and experimental results has been achieved.
AB - Cooperative principle in shape memory polymers (SMPs) result in their effective communication with the external thermochemical stimuli and then the SMPs act cooperatively to generate stimulus-responsive shape memory effect (SME). Their SME can be triggered by chemical stimuli and the corresponding thermochemically responsive behaviors are often explained by the reversible rearrangement of macromolecule segments due to changes of their configurational entropy. In this paper, we propose a new cooperative model to describe the multiple glass transitions and strain relaxations of an SMP in response to the water by means of selective and chemical plasticization effect on the partial segments in a macromolecule. Based on this model, the plasticization effect on the glass transition temperature, relaxation time and recovery strain of the SMP have been systematically investigated. Finally, the constitutive model for thermochemically responsive SMPs with two viscoelastic transitions and multiple SMEs was established to describe their overall mechanical responses, and a good agreement between the numerical and experimental results has been achieved.
KW - shape memory polymer
KW - viscoelastic transition
KW - relaxation
KW - cooperative
UR - http://www.scopus.com/inward/record.url?scp=85070810920&partnerID=8YFLogxK
U2 - 10.1088/1361-665X/ab28cc
DO - 10.1088/1361-665X/ab28cc
M3 - Article
SN - 0964-1726
VL - 28
JO - Smart Materials and Structures
JF - Smart Materials and Structures
IS - 8
M1 - 085011
ER -