Thermal oxidation of the methylene diphenylene unit in MDI-TPU

Servay, T. K.; Voelkel, R.; Schmiedberger, H.; Lehmann, S.

doi:10.1016/s0032-3861(99)00743-0

Cited by 41 publications

(35 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar results were also found in previous reports. 41 However, the beginning of the degradation temperature for this step in the current study was much different, and the temperatures of PU0, PU4, PU8, and PU12 were 437, 449, 458, and 460 C, respectively, with the PU12 temperature much higher by about 23 C compared with that of PU0. These values suggested that the PU films with more POSS are more stable.…”

Section: Thermodynamicscontrasting

confidence: 52%

Novel phenyl‐POSS/polyurethane aqueous dispersions and their hybrid coatings

Zhang

et al. 2013

J of Applied Polymer Sci

View full text Add to dashboard Cite

A facile and rapid preparation of 3-(2-aminoethylamino)propylheptaphenylPOSS (AA-POSS), a special phenyl-POSS that contains two functional amino groups (Scheme 1), is demonstrated by the corner-capping method. Then AA-POSS forms a series of novel phenyl-POSS=PU aqueous dispersions. The structure of AA-POSS has been confirmed by Si NMR, and ESI-MS. The POSS=PU hybrid films are studied by Fourier transform infrared spectrometer (FT-IR), gel permeation chromatography (GPC), scanning electron microscope (SEM), X-ray diffraction (XRD) spectra, differential scanning calorimetry (DSC) analysis, and thermal gravimetric analyzer (TGA). FT-IR and GPC are conducted to validate the chemical structure of the hybrid PU. The properties of hybrid films display significant changes with notable increases in T g , thermal properties, tensile strength, as well as surface hydrophobicity. These changes are attributed to the incorporation of novel POSS into PU. Moreover, these significant material property enhancements are achieved at low levels of POSS incorporation (only 4%).

show abstract

Section: Thermodynamicscontrasting

confidence: 52%

Novel phenyl‐POSS/polyurethane aqueous dispersions and their hybrid coatings

Zhang

et al. 2013

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…Finally, several researchers explored some principal degradation mechanism for the studied polyurethanes [17,18,[26][27][28][29][30].The three main pathways for the initial degradation stage have been described and widely-accepted [6]. Apart from this, Montaudo et al [17] claimed that the breakage and crosslinkage of regenerated polymer chains leaded to the formation of abundant volatile products and a complex macromolecule char.…”

Section: Introductionmentioning

confidence: 99%

Thermal degradation study of pure rigid polyurethane in oxidative and non-oxidative atmospheres

Jiang

Sun

et al. 2016

Journal of Analytical and Applied Pyrolysis

View full text Add to dashboard Cite

“…In literature, the presence of the new signals at 1175 cm −1 was often attributed to the formation of crosslinks between the polyol segments during in vivo and in vitro oxidation [22,49]. Nevertheless, other literature studies suggest that it may also involve the polyurethane segments and, in particular, the reactivity of groups closed to the aromatic structures[50–52]. The results obtained in this work confirm the involvement of both segments in the oxidative degradation mechanism.…”

Section: Resultsmentioning

confidence: 99%

In-vivo degradation of poly(carbonate-urethane) based spine implants

Cipriani

Bracco

Kurtz

et al. 2013

Polymer Degradation and Stability

View full text Add to dashboard Cite

Fourteen explanted Dynesys® spinal devices were analyzed for biostability and compared with a reference, never implanted, control. Both poly(carbonate-urethane) (PCU) spacers and polyethylene-terephthalate (PET) cords were analyzed. The effect of implantation was evaluated through the observation of physical alterations of the device surfaces, evaluation of the chemical degradation and fluids absorption on the devices and examination of the morphological and mechanical features. PCU spacers exhibited a variety of surface damage mechanisms, the most significant being abrasion and localized, microscopic surface cracks. Evidence of oxidation and chain scission were detected on PCU spacers ATR–FTIR. ATR–FTIR, DSC and hardness measurements also showed a slight heterogeneity in the composition of PCU. The extraction carried out on the PCU spacers revealed the presence of extractable polycarbonate segments. One spacer and all PET cords visually exhibited the presence of adherent biological material (proteins), confirmed by the ATR–FTIR results. GC/MS analyses of the extracts from PET cords revealed the presence of biological fluids residues, mainly cholesterol derivatives and fatty acids, probably trapped into the fiber network. No further chemical alterations were observed on the PET cords. Although the observed physical and chemical damage can be considered superficial, greater attention must be paid to the chemical degradation mechanisms of PCU and to the effect of byproducts on the body.

show abstract

Thermal oxidation of the methylene diphenylene unit in MDI-TPU

Cited by 41 publications

References 14 publications

Novel phenyl‐POSS/polyurethane aqueous dispersions and their hybrid coatings

Novel phenyl‐POSS/polyurethane aqueous dispersions and their hybrid coatings

Thermal degradation study of pure rigid polyurethane in oxidative and non-oxidative atmospheres

In-vivo degradation of poly(carbonate-urethane) based spine implants

Contact Info

Product

Resources

About