Locke, John

Enhancement in Tensile Mechanical and Shape Recovery Properties of Polyurethane by Incorporating Graft‐polymerized Poly(tert‐Butyl Acrylate) into Polyurethane

“…The surface modification of PU with MDI has already been reported in to improve its biocompatibility and hydrophilicity. 5,6,8,9,11 The TBA content increased with the sample number as shown in Table 1. However, the control CTBA series did not have the graftpolymerized poly(TBA) chains because the grafting agent (MDI-3) and HEMA were missing.…”

“…Grafting functional groups 1 or graft polymerizing functional monomers 2,3 onto a polymer surface has been used to modify polymer surfaces to obtain target properties such as hydrophilicity, 4-6 biocompatibility, [7][8][9] or antimicrobial activity 10,11 without significantly changing the original properties of the polymer. Polymer surfaces are usually treated with plasma discharge, 12,13 UV irradiation, 14 or ozone oxidation 15 to initiate the grafting step.…”

“…[18][19][20] Graft functionalization of the PU surface without using a high-energy treatment has been reported to improve its biocompatibility. 8 The mild grafting method was used to develop various functional PUs such as pHsensitive PU, 21 electrically conductive PU, 22 flexible PU under freezing conditions, 23 and cross-linked PU by a solgel method. 24 Additionally, the graft polymerization of polystyrene onto PU-induced low-temperature flexibility using the reduced hard segment interaction between PUs due to the grafted polystyrene.…”

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

“…The carbamate bonding in PU was the site for the graft polymerization of acryl monomers, following the functionalization method of PU in the literature. [20][21][22][23][24] The grafted PAN chains contained a series of nitrile groups in the UA series and the grafted PMMA chains contained a series of methylester groups in the UM series. The nitrile groups of UA series and the methylester groups of UM series were expected to improve the water compatibility of PU surface and water permeability of PU layer.…”

“…18,19 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 [20][21][22][23][24] and was previously demonstrated in developing functionalized PUs; e.g., PUs that exhibited flexibility at low temperatures, 25 electric attraction in aqueous solutions, 26 pH sensitivity, 27 and low temperature flexibility 28 were successfully developed. Specifically, 2-hydroxyethyl methacrylate (HEMA), a vinyl group with a hydroxyl end, was attached to the PU side using 4,4 0 -methylenebis(phenyl isocyanate) (MDI) as a grafting agent.…”