Structure–Property Correlation Study of Novel Poly(urethane–ester–siloxane) Networks

Abstract

Novel poly(urethane–ester–siloxane) networks, based on hydroxypropyl terminated poly(dimethylsiloxane) (PDMS), 4,4′-methylenediphenyl diisocyanate, and hyperbranched polyesters (HBPs) of the second and third pseudogenerations, were synthesized by two-step polymerization. The effects of the PDMS content and pseudogeneration number of HBPs on the structural, thermomechanical, thermal, and surface properties of polyurethanes were investigated. Thermomechanical and thermal properties of polyurethanes and FTIR, SAXS, and SEM results indicated good microphase separated structure. SAXS data suggested that the difference in the HBP pseudogeneration number affects only the global properties of the structure and is much less pronounced than the dependence on the PDMS content, while local properties depend only on the PDMS content. Surface characterization of samples indicated the slightly amphiphilic nature of polyurethanes. The results revealed that the synthesized polyurethanes have good thermal, thermomechanical, and surface properties, which can be tuned and adjusted for coating application by changing the PDMS content or type of the HBP.

Structure, Thermal, and Morphological Properties of Novel Macroporous Amino-Functionalized Glycidyl Methacrylate Based Copolymers

“…This can be attributed to the increase in cross-linking density that restricts the molecular motion of the polymer chains and leads to the increase in T g . 30 The glass transition temperatures of the initial copolymers are very similar to the glass transition temperatures of functionalized copolymers (Table 2). Furthermore, T g values do not seem to depend on the type of amines attached to the poly(GMA-co-EGDMA).…”

Synthesis and characterization of a novel polyurethane curing agent modified by a diazafluorene derivative

“…In contrast, there were no fine ripples in the brittle fracture of the sample cured in N75. Therefore, the PU cured in the novel CA exhibited a higher impact strength in comparison to that cured in N75 because of the special structure of the diazafluorene derivative, which enhanced the friction steric hindrance within the molecular chains available for improving the mechanical properties …”

Synthesis and structure-property relationships of biodegradable polyurethanes

“…The synthesis of PU copolymers using siloxane-containing prepolymers with PCL and ethylene oxide terminal units has been described [90][91][92][93][94][95][96][97][98]; these terminal units of siloxane-containing prepolymers were used in order to increase the miscibility of polar and non-polar reactants. Thermoplastic PU elastomers based on PDMS were synthesized by a two-step polyaddition procedure in solution, from MDI, 1,4-BD and α,ω-dihydroxy-PCL-b-PDMS-b-PCL [94].…”