Hydrolytic stability and protective properties of polyurethane oligomers based on polyester/ether/polyols

Pavlova, M.; Draganova, M.; Novakov, P.

doi:10.1016/0032-3861(85)90023-0

Cited by 5 publications

(3 citation statements)

References 3 publications

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“…The ether and ester bonds have lower hydrolytic stability than the urethane bond [1]. Pavlova et al determined the hydrolytic stability of polyurethanes based on polyester and polyether polyols and concluded that the hydrolytic stability of polyether polyols was higher in alkaline (20% NaOH) and aqueous media while polyester polyols were more stable in acidic medium (20% HNO 3 ) [2]. The hydrolysis of urethane bonds requires extreme conditions, such as temperatures over 100 o C or highly alkaline or acidic conditions.…”

Section: Fig 1: General Urethane Condensation Reactionmentioning

confidence: 99%

Removal of toluene diamine and its derivatives from polyurethane foam using immobilized Trametes versicolor

2019

Adv. Environ. Biol

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Background: In addition to uses in home furnishings and the construction sector, polyurethane foam (PUF) is also prevalent in medical products such as scaffolds and implants. However, these applications raise concerns for human health as the use of this material can result in exposure to the carcinogenic substance 2,4-toluenediamine (2,4-TDA). The objective of this study was to identify easily extracted PUF-residuals and to study the removal of them in a biodegradation experiment including immobilized Trametes versicolor. Ultra-high-performance liquid chromatography-quadrupole/time of flight mass spectrometry (UHPLC-Q-TOF MS) was used in MS and MS/MS-mode to confirm the identities of PUF-related compounds and follow their concentration changes. Results: Except for 2,4-TDA and 2,6-TDA which were confirmed by standards, previously not reported substances were tentatively identified, among them TDA-dimers. These dimers include homodimers, heterodimers containing 2,4-TDA and 2,6-TDA and compounds that are hydroxylated. The experiments that were performed in an acidic fungal culture revealed a not previously described removal of these compounds below the approximate nM detection limit. The mechanisms behind their removal may include biosorption to fungal mycelia, bioaccumulation, use of them as nutrients or extracellular catabolism. Conclusion: The results of this study not only highlight the ease by which harmful compounds were extracted from the investigated PUF-quality which is used in non-medical applications, but also the possibility to use fungal-based methods to eliminate them. This could be facilitated by an initial extraction of PUF (excluding fungi) followed by a removal of the substances with PUF-immobilized Trametes versicolor. The findings in this study may be of interest to further investigate PUF-residuals in products aimed for medical applications.Citation: Åke Stenholm et al., 2019. Removal of toluene diamine and its derivatives from polyurethane foam using immobilized Trametes versicolor. Advances in Environmental Biology 13(2): 17-29.

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Section: Fig 1: General Urethane Condensation Reactionmentioning

confidence: 99%

Removal of toluene diamine and its derivatives from polyurethane foam using immobilized Trametes versicolor

2019

Adv. Environ. Biol

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“…A síntese de polímeros dispersos em água constitui um verdadeiro avanço tecnológico, principalmente na área de materiais para revestimento, onde tradicionalmente são empregadas soluções em solventes orgânicos [3][4][5][6][7][8][9][10][11][12][13][14][15][16] . Neste último caso, após a aplicação da solução ocorre a evaporação do solvente orgânico para o meio ambiente, o que é, atualmente, proibido na Europa, por exemplo.…”

Section: Introductionunclassified

“…Os problemas do meio ambiente têm estado presentes em praticamente todas as reuniões de Chefes de Estado, seja em relação à redução na emissão de compostos orgânicos voláteis (VOC's), no controle da degradação de reservas ambientais, ou no desenvolvimento auto-sustentável (DS) [1,2] . Dessa forma, a produção de sistemas químicos menos agressivos tem sido o foco de muitos trabalhos de pesquisa [3][4][5][6][7][8][9][10][11][12][13][14] .A síntese de polímeros dispersos em água constitui um verdadeiro avanço tecnológico, principalmente na área de materiais para revestimento, onde tradicionalmente são empregadas soluções em solventes orgânicos [3][4][5][6][7][8][9][10][11][12][13][14][15][16] . Neste último caso, após a aplicação da solução ocorre a evaporação do solvente orgânico para o meio ambiente, o que é, atualmente, proibido na Europa, por exemplo.…”

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Dispersões aquosas poliuretânicas à base de polibutadieno hidroxilado: influência das variáveis reacionais

2007

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Resumo: Neste trabalho foram produzidas dispersões aquosas poliuretânicas com formulações variadas, em ausência de solvente orgânico. Nas sínteses, foram empregados o diisocianato de isoforona (IPDI) e como polióis, o poli(glicol propilênico) (PPG) e diferentes tipos de polibutadieno líquido hidroxilado (HTPB) comerciais. Para promover a dispersão das cadeias poliméricas em água, foi utilizado o ácido dimetilolpropiônico (DMPA), que após neutralização com trietilamina (TEA) forneceu os sítios iônicos responsáveis pela estabilidade das partículas dispersas no meio aquoso. Como extensor de cadeia foi utilizada a hidrazina (HYD). As dispersões aquosas poliuretânicas obtidas foram avaliadas quanto ao teor de sólidos totais, tamanho médio de partícula e viscosidade aparente. Não foram observadas variações significativas nesses valores, que ficaram em faixas pequenas, independentemente da formulação. Os filmes formados a partir dessas dispersões foram avaliados quanto às suas características visuais, adesão e propriedades mecânicas. Os filmes apresentaram boa aderência a superfícies de alumínio, transparência e flexibilidade e aqueles produzidos com baixos teores de DMPA e/ou baixa razão NCO/OH apresentaram melhores propriedades mecânicas. Palavras-chave: Poliuretanos, síntese, dispersões aquosas, polibutadieno líquido hidroxilado, diisocianato de isoforona. Development of Polyurethane Aqueous Dispersions Based on Hydroxy-terminated Polybutadiene: Reaction VariablesAbstract: In this work, polyurethane aqueous dispersions with different formulations were produced in the absence of organic solvents. In the synthesis, isophorone diisocyanate (IPDI), poly(propylene glycol) (PPG) and different types of hydroxy-terminated polybutadiene (HTPB) were employed. In order to make possible the dispersion of the polyurethane chains in water, dimethylolpropionic acid (DMPA), was used. Afterwards the acid groups were neutralized with triethylamine (TEA) to provide the ionic groups responsible for the particles stability in water. The solids content, viscosity and particle size of the formulations produced in this work were evaluated. These parameters were found to vary within a narrow range, regardless of the formulation. The films were transparent, flexible and showed a good adherence on aluminum surfaces. Their mechanical properties were satisfactory, particularly those obtained with higher contents of DMPA and at low values of NCO/OH ratio. Keywords: Polyurethanes, synthesis, aqueous dispersions, hydroxyl-terminated polybutadiene, isophorone diisocianate. IntroduçãoNos últimos anos, as questões ambientais têm merecido um papel de destaque na mídia nacional e internacional. Os problemas do meio ambiente têm estado presentes em praticamente todas as reuniões de Chefes de Estado, seja em relação à redução na emissão de compostos orgânicos voláteis (VOC's), no controle da degradação de reservas ambientais, ou no desenvolvimento auto-sustentável (DS) [1,2] . Dessa forma, a produção de sistemas químicos menos agressivos tem sido o foco ...

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Degradation of adhesive composites

Kovačević

Hace

Bravar

et al. 1988

Angew. Makromol. Chem.

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Die Angewandte Makromolekulare Chemie 158/159 (1988) 265-282 (2681) Faculty o f Technology, University of Zagreb, 41000 Zagreb, Yugoslavia a b b e r and Footwear Combine Bomvo, B~M V O , Yugoslavia DEGRADA!TION OF ADHESIVE CC#POSITES Vera KovaEevi6, Drago Hace, I r i n e j Mudri*, Mladen Bravar,and %el jko CeroveEki SuMMpgI Composite materials consisting of natural l e a t h e r and polyurethane elastomers, and bonded together by polyurethane adhesives, were submitted t o accelerated ageing a t various t e s t i n g conditions. The extent of the degradation of these composites was evaluated through t h e determination of mechanical strength reduction and through the i n s i g h t i n t o t h e s t r u c t u r a l and chemical transformat i o n s of t h e adhesive polymeric materials. Founded data correlations indicate t o the mechanism and t o the relevant f a c t o r s t h a t influence of ageing processes. Succesful bonding of polymeric materials relyes on complex phenomena of cohesion, autohesion and adhesion by which many types of physical and chemical bonds are expected t o be formed. Their formation, i n turn, strongly depends on the chemical nature and on the structure of both the substrate and t h e adhesive, f i r t h e r o f the Substrate surface, of the proper bonding conditions, but last

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Hydrolytic stability and protective properties of polyurethane oligomers based on polyester/ether/polyols

Cited by 5 publications

References 3 publications

Removal of toluene diamine and its derivatives from polyurethane foam using immobilized Trametes versicolor

Removal of toluene diamine and its derivatives from polyurethane foam using immobilized Trametes versicolor

Dispersões aquosas poliuretânicas à base de polibutadieno hidroxilado: influência das variáveis reacionais

Degradation of adhesive composites

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