Shape Memory Polymer Foam with Programmable Apertures

Abstract

In this work, a novel type of polyester urethane urea (PEUU) foam is introduced. The foam was produced by reactive foaming using a mixture of poly(1,10–decamethylene adipate) diol and poly(1,4–butylene adipate) diol, 4,4′-diphenylmethane diisocyanate, 1,4–butanediol, diethanolamine and water as blowing agent. As determined by differential scanning calorimetry, the melting of the ester-based phases occurred at temperatures in between 25 °C and 61 °C, while the crystallization transition spread from 48 °C to 20 °C. The mechanical properties of the foam were simulated with the hyperplastic models Neo-Hookean and Ogden, whereby the latter showed a better agreement with the experimental data as evidenced by a Pearson correlation coefficient R² above 0.99. Once thermomechanically treated, the foam exhibited a maximum actuation of 13.7% in heating-cooling cycles under a constant external load. In turn, thermal cycling under load-free conditions resulted in an actuation of more than 10%. Good thermal insulation properties were demonstrated by thermal conductivities of 0.039 W·(m·K)−1 in the pristine state and 0.052 W·(m·K)−1 in a state after compression by 50%, respectively. Finally, three demonstrators were developed, which closed an aperture or opened it again simply by changing the temperature. The self-sufficient material behavior is particularly promising in the construction industry, where programmable air slots offer the prospect of a dynamic insulation system for an adaptive building envelope.

Actuating Shape Memory Polymer for Thermoresponsive Soft Robotic Gripper and Programmable Materials

“…Poly(1,10-decylene adipate) diol (PDA) is a promising building block both in the chemistry of polyester urethanes and polyester urethane ureas [25]. It was synthesized in the present work in a polycondensation reaction from 1,10-decanediol and adipic acid (Figure 1).…”

“…As known from semicrystalline polyester urethane (PEU), actuation can also be very pronounced and complies with the same physical principles [24]. The fact that polymers react to temperature changes in their surroundings makes them interesting candidates for applications in which complex switching and control electronics are to be avoided [25]. For example, in the field of soft robotics, a specific subfield of robotics that deals with the construction of robots from highly compliant materials [26][27][28], first steps were taken to demonstrate the attractiveness of SMPs [29][30][31][32].…”

Recent advances on π-conjugated polymers as active elements in high performance organic field-effect transistors

“…electrochromic devices [6][7][8], memory [9,10], organic solar cells (OSC) [11][12][13][14][15] and organic light-emitting diodes (OLED) [16,17]. With the joint efforts from molecular design, processing technology and device construction, superior electronic properties have been achieved.…”

Nonlinear Finite Element Modelling of Thermo-Visco-Plastic Styrene and Polyurethane Shape Memory Polymer Foams

“…Some of these models are impressively effective in predicting nonlinear, timeand temperature-dependent responses of various polymers. Recently, Walter et al [34] presented a simple model according to the neo-Hookean model in commercial finite element (FE) software package for shape memory polyester urethane urea (PEUU) foam. Among the weak points of these models are their need for developing additional user-defined codes in the commercial software packages, a large number of experimental parameters required for the proper prediction of the material behavior, as well as being computationally costly.…”