Shape Memory of Hydrogen-Bonded Polymer Network/Poly(ethylene glycol) Complexes

Abstract

Because of a large difference in storage modulus below and above the glass transition temperature, poly(acrylic acid-co-methyl methacrylate)/poly(ethylene glycol) (P(AA-co-MMA)/PEG) complexes show shape memory properties with a recovery ratio of nearly reach 99%. Before the shape memory testing, it was necessary to determine the conformational changes of the P(AA-co-MMA) gel induced by complexation with linear PEG. It was found that both the concentration and molecular weight of PEG have a strong effect on the complexation with P(AA-co-MMA) gel. In such a system the minimum molecular weight of PEG required for the complex formation lowers to 1000.

Phase behavior predictions for polymer blends containing reversibly associating endgroups

“…The ability to reversibly transform a noncovalent polymer, gel, or crosslinked elastomer into a low-molecular weight liquid offers an approach to reducing the energy costs associated with polymers and materials processing and could foster technologies including thermoplastic elastomers 24,25 and shape memory polymers. 26,27 An improved understanding of phase behavior of blends containing associating terminal groups will aid in developing such applications. Associating endgroups may also enable new polymer blends containing traditionally immiscible polymers and will further development the concept of supramolecular block copolymers.…”

Review on the Functional Determinants and Durability of Shape Memory Polymers

“…In this way, the environment, which is used to evaluate SM properties, is equalized with the utilized thermo-mechanical characterization method. Applications for SMPs are diverse and involve deformations like bending, compression and drawing, accordingly there are different testing methods to quantify the SM behavior of a polymer, such as bending tests [174][175][176], fold-deploy tests [135], uniaxial experiments (unconstrained free strain recovery tests, stress recovery tests under full constraint at a fixed strain level [101,177], isothermal uniaxial compression tests [178] and other tests developed for SMP foams [179][180][181][182][183]) and isothermal free strain recovery tests in warm water baths, during which a video camera collects images at a well-defined rate, e.g., at 20 frames-per-second ( Figure 1) [184,185]. In some cases, a dynamic mechanical analyzer has been used to evaluate SM properties [88].…”

Supramolecular Network Based on the Self‐Assembly of γ‐Cyclodextrin with Poly(ethylene glycol) and its Shape Memory Effect

“…The method of evaluating the shape memory effect was according to Liu et al [13] A straight strip of the specimen was deformed to an the actual mass content of inclusion segments was calculated from 1 H NMR spectroscopy.…”