Structural and end‐group effects on bulk and surface properties of hyperbranched poly(urea urethane)s

Abstract

The hydroxy end groups of aromatic and aliphatic hyperbranched poly‐(urea urethane)s prepared with an AA* + B*B2 one‐pot method were modified with phenylisocyanate, butylisocyanate, and stearylisocyanate. The success of the modification reaction was verified with 1H NMR and IR spectroscopy. Linear model poly‐(urea urethane)s were prepared, too, for comparison. The bulk properties of OH functionalized hyperbranched poly(urea urethane)s, compared with those of linear analogues and modified hyperbranched poly(urea urethane)s, were studied with differential scanning calorimetry, thermogravimetric analysis, and temperature‐dependent Fourier transform infrared measurements. Transparent and smooth thin films could be prepared from all polymer samples and were examined with a light microscope, a microglider, and an atomic force microscope. The properties of the polymer surface were examined by measurements of the contact angle and zeta potential. For all samples, the properties were mainly governed by the strong interactions of the urea and urethane units within the backbone, whereas the influence of the nature of the end groups and of the branched structure was reduced in comparison with other hyperbranched polymer systems. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3376–3393, 2005

Dendritic Polymers Based on Urethane Chemistry – Syntheses and Applications

“…[36,37] Structural effects and end group effects by modification of the molecular surface of these hyperbranched polyurea urethanes in bulk and in thin films have been investigated. [38] Fractionation by preparative SEC and analysis of the fractions via MALLS, MALDI-TOF-MS and NMR spectroscopy revealed a strong influence of the end groups on solubility and proved to be very compact structures in solution compared to linear polyurea urethane model systems. [39] An oligomeric A 2 þ B 3 -approach towards hyperbranched segmented poly(urethane-urea) elastomers was reported by Long, Yilgor and coworkers.…”

Synthesis and properties of LED-packaging epoxy resin toughened by a novel polysiloxane from hydrolysis and condensation

“…The chemical structures of G x D y were confirmed by FTIR, 29 Si NMR and GPC spectroscopic analyses. Figure 2 shows the FTIR spectra of G x D y .…”

“…FTIR and 29 Si NMR: The infrared spectrum (FTIR) was recorded with a WQF-410 FTIR (BRAIC, China). 29 Si NMR was performed on a 400 MHz Brüker NMR spectrometer (Brüker, Germany) with CDCl 3 as solvent. According to the different chemical shifts of the hydrolysis and condensation species of the silane components, the degree of condensation (DOC) was calculated by integration of the individual signals as follows:…”

Synthesis of Benzene Tetracarboxamide Polyamine and Its Effect on Epoxy Resin Properties

“…Flexural strength data in Figure 9 show that the addition of flexural BTCP does not result in a loss of flexural strength, as compared to that in a neat epoxy composition, unlike other toughening agents, which decrease the flexural strength [13,33]. (Figure 3b) after curing the epoxy polymer [31]. Additionally, the primary amines of BTCP react with the glycidyl ether of the epoxy resin to participate in the epoxy polymer network.…”

“…Therefore, the epoxy compositions with BTCP are predicted to compensate for the brittleness of the epoxy polymer due to the lower crosslinking density. (Figure 3b) after curing the epoxy polymer [31]. Additionally, the primary amines of BTCP react with the glycidyl ether of the epoxy resin to participate in the epoxy polymer network.…”