Effects of Loading Rate on the Relaxation and Recovery Ability of an Epoxy-Based Shape Memory Polymer

McClung, Amber J. W.; Tandon, G. P.; Baur, Jeffery W.

doi:10.3390/fluids2020013

Cited by 7 publications

(1 citation statement)

References 35 publications

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“…Numerical analyses have shown that fibre elasticity is a key factor for the shape fixity of the composite, while the shape recovery also depends on the strain concentration near the fibre ends [3]. For the matrix, many polymers exhibit good SM behaviour but thermosetting resins generally show higher SM properties than thermoplastic, and epoxies are particularly suitable for this task [4,5]. SM epoxies also have better mechanical and thermal properties.…”

Section: Introductionmentioning

confidence: 99%

Shape memory polymer composite unit with embedded heater

Quadrini

Iorio

Bellisario

et al. 2021

Smart Mater. Struct.

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A shape memory polymer composite (SMPC) unit has been manufactured with embedded heater. The structure of the SMPC unit has been designed to allow reaching high recovery loads with a reduced size of the functional device. The unit is a composite sandwich with four carbon fibre reinforced (CFR) plies, two SMP foam cores, and one SMP interlayer. In the mid-plane of the sandwich the heater is integrated, being immersed in the SMP interlayer. The adopted manufacturing procedure was able to provide the necessary consolidation in one step moulding thanks to the use, during lamination, of pre-formed SMP cores, and uncured SMP powder for the interlayer. The SMP cores were manufactured by solid state foaming of the same SM epoxy powder. SMPC laminates, without the embedded heater, were also manufactured for testing as well as traditional four-ply CFR laminates. Several tests were carried out for temperature calibration and for investigating SM properties of the SMPC laminates and unit. Dynamic mechanical analyses, hot bending tests, and microscopic observations were performed on CFR and SMPC laminates. It was found that the SMP layers reduce the glass transition temperature of the laminates as well as the transition onset temperature and, above all, the extension of the transition range thus providing the trigger effect to the SMPC transition. Double-cycle SM tests were carried on the SMPC unit at different temperatures from 160 °C to 190 °C. The unit (20 × 45 mm2) was able to exert recovery loads over 7.4 N almost independently from the temperature and without any evidence of failure after several repeated tests. High values were measured also for the shape fixity and shape recovery which were, on average, higher than 96% and 95%, respectively.

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Section: Introductionmentioning

confidence: 99%