Effects of thermal degradation products from polyurethane foams based on toluene diisocyanate and diphenylmethane diisocyanate on isolated, perfused lung of guinea pig

Låstbom, Lena; Colmsjö, Anders; Karlsson, Daniel; Melin, Jens; Nordqvist, Yvonne; Skarping, Gunnar

doi:10.5271/sjweh.717

Cited by 9 publications

(10 citation statements)

References 21 publications

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“…39 -41 Similar observations have been made for polyether-urethane 42,43 ; however, the same scientist has found a contradicting evidence. 44 The monomers could have been cracked free from the polyether-urethane structure during processing, [45][46][47] since the molecular weight was changed during production of the polymer sample. Processing degradative behavior is further discussed in the next section.…”

Section: Discussionmentioning

confidence: 99%

Effect of different γ‐irradiation doses on cytotoxicity and material properties of porous polyether‐urethane polymer

et al. 2006

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Biomaterials respond to sterilization methods differently. Steam sterilization might decrease the performance of thermoplastic polyether-urethane (TPU); however, the effect of different gamma-radiation doses on this polymer is contradictory in present literature. The purpose of this study was to investigate the differences between irradiative doses in comparison with steam sterilization on a porous TPU scaffold produced by a new processing method. No significant differences in the surface chemical structure were found with attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) analysis when comparing with the sterilization methods. The molecular weight (M(w)) had a net increase from 11.5 +/- 0.039 to 13.2 +/- 0.072 kDa by gamma-sterilization from 10 to 60 kGy. The samples that were irradiated (>60 kGy) had also an increase in polydispersity index (PDI; 1.45 +/- 0.007) in comparison with the nonsterile ones (1.31 +/- 0.017), which indicate branching. Liquid chromatography/mass spectroscopy (LC/MS) analysis showed that there was a correlation between the concentration of the breakdown product, methyl dianiline, and cytotoxicity. The concentration of this compound was found to be four times higher in steam-sterilized sample (1.3 +/- 0.01 ppb) compared with that of the polymer sample gamma-sterilized at 10 kGy (0.3 +/- 0.01 ppb). The cytotoxicity of TPU was found to decrease with higher radiation doses, and was significantly higher for the steam-sterilized samples. It is recommended that TPU produced with the described foaming method should be sterilized by gamma-irradiation at 25 kGy or higher doses.

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Section: Discussionmentioning

confidence: 99%

Effect of different γ‐irradiation doses on cytotoxicity and material properties of porous polyether‐urethane polymer

et al. 2006

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“…This leads to release of MDA. Other degradation products may also be produced 28. However, this study has focused on the detection of MDA, as it might be the most toxic of the degradation products from polyether–urethane 18.…”

Section: Methodsmentioning

confidence: 99%

“…Other degradation products may also be produced. 28 However, this study has focused on the detection of MDA, as it might be the most toxic of the degradation products from polyether-urethane. 18 The release of the toxic breakdown product methylene dianiline (MDA) from the material was considered to be possible.…”

Section: Degradation Productmentioning

confidence: 99%

Biostability of polyether–urethane scaffolds: A comparison of two novel processing methods and the effect of higher gamma‐irradiation dose

et al. 2005

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This article deals with enzyme-induced biodegradation behavior of thermoplastic polyether-urethane (TPU). Porous scaffolds were processed by a new foaming method applied in hot pressing and injection molding. The scaffolds were subsequently gamma sterilized. The samples were incubated with cholesterol esterase (CE) for 28 days to simulate an enzymatic degradation order to assess polymer biostability. The main focus of degradation products was the most toxic one: methylene dianiline (MDA). LC/MS was used to separate the breakdown products and to identify possible MDA amounts. The results showed that (a) the hot-pressed sample released an MDA amount almost twice as large (0.26 ng +/- 0.008) as that of the injection-molded samples (0.15 ng +/- 0.003) after incubation with enzyme activity in the physiological range, and (b) a tenfold increase in CE activity revealed considerably higher MDA amounts (7540.0 ng +/- 0.004). This enzyme concentration is physiologically unlikely, however, but may occur for extreme high inflammation behavior. Even for extremely high levels of CE enzyme, the scaffold will not discharge MDA above toxic levels. The injection-molded samples sterilized at 25 kGy seem to represent the most promising processing method. Therefore, the new injection-molding foaming process of polyether-urethane can be considered appropriate for use as a biomaterial.

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“…Given their importance, it is no surprise that there is a considerable literature on the thermal degradation chemistry of polyurethanes [see for example [1][2][3][4][5][6][7][8][9][10][11][12][13], although studies on foam materials are more limited in number, with many studies focussing on elastomers or model compounds.…”

Section: Introductionmentioning

confidence: 99%

“…It is generally accepted that the purely thermal degradation of the urethane linkages within polyurethane (the primary degradation step) occurs between 200°C and 250°C by one or more of three mechanisms: (i) a simple depolymerisation to regenerate isocyanate and hydroxyl groups, (ii) a six-membered cyclic transition state producing amine and alkene chain ends and CO 2 , (iii) a four-membered transition state liberating CO 2 without chain scission. It has been reported by many authors that the depolymerisation reaction (i) is the predominant degradation reaction for the urethane linkage [2,3,[5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Oxidative and non-oxidative degradation of a TDI-based polyurethane foam: Volatile product and condensed phase characterisation by FTIR and solid state 13C NMR spectroscopy

Allan

Daly

Liggat

2019

Polymer Degradation and Stability

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Effects of thermal degradation products from polyurethane foams based on toluene diisocyanate and diphenylmethane diisocyanate on isolated, perfused lung of guinea pig

Cited by 9 publications

References 21 publications

Effect of different γ‐irradiation doses on cytotoxicity and material properties of porous polyether‐urethane polymer

Effect of different γ‐irradiation doses on cytotoxicity and material properties of porous polyether‐urethane polymer

Biostability of polyether–urethane scaffolds: A comparison of two novel processing methods and the effect of higher gamma‐irradiation dose

Oxidative and non-oxidative degradation of a TDI-based polyurethane foam: Volatile product and condensed phase characterisation by FTIR and solid state 13C NMR spectroscopy

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