Grafting of shape memory polyurethane with poly(ethyleneimine) and the effect on electrolytic attraction in aqueous solution and shape recovery properties

Abstract

Shape memory polyurethane (SMPU) grafted using polyethyleneimine (PEI) was tested for its electrolytic attraction in aqueous solution and shape memory effect. The PEI was connected through a second 4,4'-diphenylmethane diisocyanate anchored to the carbamate moiety of SMPU. Two series of SMPU that differed in soft segment polytetramethylene glycol and PEI content were prepared to compare their tensile and shape memory properties. Shape recovery was high as 99% and reduced only to 97% after four test cycles. The PEI group attached to the SMPU chain, if converted to the imminium salt form, was designed to work as an electrolyte during water electrolysis and was to be attracted toward the cathode to show SMPU movement in aqueous solution. The electrolytic attraction of SMPU in aqueous solution was demonstrated in an experiment in which a specimen moved to the cathode only when voltage above a minimum was applied. The mechanism and application of this finding are discussed.

Graft Polymerization of Polyacrylonitrile or Poly(methyl methacrylate) onto Polyurethane for the Improvement of Mechanical Properties and Water Vapor Permeability

“…The CO stretch peaks at approximately 1700 and 1730 cm −1 were used to analyze the intermolecular interactions, such as hydrogen bonding and dipole–dipole interactions, between the hard segments of PU. The bonded carbonyl stretch (1700 cm −1 ) appeared at a lower wavenumber than did the free carbonyl stretch (1730 cm −1 ) . The relative intensities of the bonded and free carbonyl stretch vibrations were used to compare the degree of phase separation (DPS) between UA and UM series, which indicated the change in the molecular interactions between carbonyl groups.…”

“…PAN or PMMA chains were grown from the active sites on PU (graft‐from approach), and the number of PAN or PMMA chains was varied. This PU surface grafting method has been reported in the literature and was previously demonstrated in developing functionalized PUs; e.g ., PUs that exhibited flexibility at low temperatures, electric attraction in aqueous solutions, pH sensitivity, and low temperature flexibility were successfully developed. Specifically, 2‐hydroxyethyl methacrylate (HEMA), a vinyl group with a hydroxyl end, was attached to the PU side using 4,4′‐methylenebis(phenyl isocyanate) (MDI) as a grafting agent.…”

Modification of polyurethane by graft polymerization of poly(acrylic acid) for the control of molecular interaction and water compatibility

“…This PU surface grafting method has been reported in the literature [18][19][20][21][22] and was previously demonstrated by our group in developing functionalized PUs; for example, PUs that exhibited flexibility at low temperatures [23], electric attraction in aqueous solutions [24], pH sensitivity [25], and photoluminescence [26] were successfully developed. Specifically, 2-hydroxyethyl methacrylate (HEMA), a vinyl group with a hydroxyl end, was attached to the PU side using MDI as a grafting agent.…”

Preparation of water‐compatible antifungal polyurethane with grafted benzimidazole as the antifungal agent

“…We demonstrated that the grafting of functional groups onto PU produces functionalized PUs from unfunctionalized PUs. For example, PUs that exhibited flexibility at low temperatures, electric attraction in aqueous solutions, magnetism, pH‐indicating abilitiy, and photoluminescence have been developed. However, the development of antifungal PUs with antifungal agents has not been reported so far, although some antimicrobial polymers containing quaternary ammonium groups have been researched .…”