A unified modeling approach for amorphous shape memory polymers and shape memory polymer based syntactic foam

Abstract

Shape memory polymers (SMPs) and shape memory polymer composites have drawn considerable attention in recent years for their shape memory effects. A unified modeling approach is proposed to describe thermomechanical behaviors and shape memory effects of thermally activated amorphous SMPs and SMP-based syntactic foam by using the generalized finite deformation multiple relaxation viscoelastic theory coupled with time-temperature superposition property. In this paper, the thermoviscoelastic parameters are determined from a single dynamic mechanical analysis temperature sweep at a constant frequency. The relaxation time strongly depends on the temperature and the variation follows the time-temperature superposition principle. The horizontal shift factor can be obtained by the Williams-Landel-Ferry equation at temperatures above or close to the reference temperature (T r ), and by the Arrhenius equation at temperatures below T r . As the Arruda-Boyce eight-chain model captures the hyperelastic behavior of the material up to large deformation, it is used here to describe partial material behaviors. The thermal expansion coefficient of the material is regarded as temperature dependent. Comparisons between the model results and the thermomechanical experiments presented in the literature show an acceptable agreement.

Development and Mechanical Characterization of HGMS–EHS-Reinforced Hollow Glass Bead Composites

“…HGMSs are hollow glass thin-walled beads with a diameter ranging from several micrometers to hundreds of micrometers and appear gray or white. − It has many advantages such as loose drying, good fluidity, strong mechanical properties, low density, and so forth. , The density of the HGMSs is generally in the range of 0.1–0.6 g/cm 3 , and the density of the three-phase composite buoyancy material prepared from the reinforced hollow spheres thereof is generally in the range of 0.2–0.7 g/cm 3 . − Solid foam materials can be classified into one-phase foam materials and two-phase and three-phase syntactic foam materials because of their different compositions. , The one-phase foam material mainly refers to a polymer-based foamed material such as a polystyrene foam material and a polyurethane foam material. − The polymer foamed material has a low compressive strength and is highly limited. The two-phase syntactic foam material refers to a composite of epoxy resin (EP) and hollow glass microbeads, and the added HGMSs reduce the density of the buoyant material and show good compressive strength. , The three-phase syntactic foam material is based on a two-phase syntactic foam material with some hollow materials, such as hollow glass bead-reinforced hollow spheres .…”

Analysis and modeling of modified styrene–acrylonitrile/carboxylated acrylonitrile butadiene rubber nanocomposites filled with graphene and graphene oxide: Interfacial interaction and nonlinear elastoplastic behavior

“…The response of the network A can be expressed using the eight-chain model (known as Arruda-Boyce model) [23] and based on nonlinear Langevin chain statistics and Cauchy stress on network A is represented by Equation ( 4). [24] T A ¼ μ…”

A comprehensive review on thermomechanical constitutive models for shape memory polymers

“…They assumed a polynomial function (temperature dependent) to calculate the shift factor. In order to improve the model of Arrieta et al (2014b), Gu et al (2016), by writing the storage and loss modulus in terms of temperature, optimized them according to DMTA test results at a constant frequency. This way they were able to identify viscoelastic coefficients and TTSP parameters, simultaneously.…”

“…Fang et al (2018), employing the Generalized Maxwell fractional elements, predicted the shape-retrieval behavior of an amorphous PFSA with a large glassy transition temperature range. It is noteworthy that Fang et al (2016) used the experiments by Xie (2010), Westbrook et al (2011a), Nguyen et al (2010), and Gu et al (2016), respectively, for a PFSA, acrylate-based network polymer, tBA-co-PEGDMA networks, and styrene-based thermoset resin (syntactic foam-based SMP). Then, following the phase transition approach, similar to the approach provided by Barot and Rao (2006) for semi-crystalline SMPs, Moon et al (2015) modeled a triple-SMP based on poly(ω-pentadecalactone) (PPD) and PCL in 3D large deformations.…”