Synthesis and characterization of poly(propylene glycol) polytrioxamide and poly(urea oxamide) segmented copolymers

Abstract

This report describes the synthesis and characterization of unprecedented poly(propylene glycol) (PPG) polytrioxamide and poly(urea oxamide) (UOx) segmented copolymers containing monodisperse hard segments. Synthesis of the segmented copolymers relied on an efficient two‐step end‐capping sequence, which resulted in novel difunctional oxamic hydrazide‐terminated polyether oligomers. Polymerization with oxalyl chloride or 4,4′‐methylenebis(cyclohexyl isocyanate) provided the desired segmented copolymers displaying thermoplastic elastomeric behavior. Variable‐temperature Fourier transform infrared and 1H NMR spectroscopies confirmed the presence of hard segment structures and revealed ordered hydrogen bonding interactions with thermal dissociation profiles similar to those of polyurea and polyoxamide copolymer analogs. Dynamic mechanical analysis of PPG‐UOx exhibited a longer, rubbery plateau with increased moduli compared to PPG polyurea, and tensile analysis revealed a dramatic increase in copolymer toughness due to enhanced hydrogen bonding. A new step‐growth polymerization strategy is described that is capable of producing tunable hydrogen bonding segmented copolymer architectures. © 2013 Society of Chemical Industry

Amide-containing segmented copolymers

“…Poly(urea oxamide) copolymers also demonstrated a higher Young's moduli and stress at break, but a decrease in the strain at break resulted. [113,115] Oxamide …”

“…PTMObased poly(oxamide)s also showed a high moduli >120 MPa with stress and strain at break up to , copolymer composition and level of crystallinity greatly affected the mechanical properties [114]. DMA revealed long, temperature-insensitive, service windows up to 180 ˚C for PDMS poly(oxamide) copolymers, and the rubbery plateau length and storage moduli varied with copolymer composition(Figure 17) [111,113,114] [111]. Recent reports include the structure-property relationships of poly(oxamide) copolymers for both PTMO and PDMS based copolymers.…”

Sugar‐Derived Poly(β‐thioester)s as a Biomedical Scaffold

“…[34] The appearance of a shoulder in the CO stretch as temperature increased could also indicate that a shift from ordered to disordered hydrogen bonds also occurred. Previous work in our laboratories studying oxamide‐containing copolymer revealed a similar presence of disordered hydrogen bonds with increasing temperature . Thus, the transition observed by DSC at ≈70 °C likely corresponded to the dissociation of amide hydrogen bonding due to the incorporation of the MBAm comonomer.…”

“…Previous work in our laboratories studying oxamide-containing copoly mer revealed a similar presence of disordered hydrogen bonds with increasing temperature. [46][47][48] Thus, the transition observed by DSC at ≈70 °C likely corresponded to the dissociation of amide hydrogen bonding due to the incorporation of the MBAm comonomer. The high temperature of the transition (70 °C) indicated that the material should maintain mechanical integrity at body temperature despite being well above T g .…”

Synthesis and properties of bio‐based poly(pentamethylene oxamide)

“…In this study, the saturated water absorption of PA52 is measured to be 3.2 wt%, which is only about one third of that of PA6 (about 10 wt% ) and about one fourth of PA46 (12.4 wt% ). This low saturated water absorption should be mainly attributed to the unique adjacent double hydrogen‐bonds in POA and high crystallinity of PA52, which gives it better dimensional stability compared with PA6.…”