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Bakirova, I. N.; Shagidullin, R. R.; Avvakumova, L. V.; Demchenko, I. G.; Zenitova, L. A.

doi:10.1023/a:1025625406676

Cited by 4 publications

(4 citation statements)

References 3 publications

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“…Generally, polyol and isocyanate can form three types of bonds by the reaction, namely normal urethane bonds, biuret linkages, and allophanate linkages . Among these three bonds, biuret and allophanate linkages are thermally less stable because their complete thermal degradation can be reached at 170–180 °C . Since, below 200 °C, no weight loss was observed for the present synthesized PU, it can be concluded that there is no significant number of biuret and allophanate linkages in the present PU.…”

Section: Resultsmentioning

confidence: 68%

“…51 Among these three bonds, biuret and allophanate linkages are thermally less stable because their complete thermal degradation can be reached at 170-180 8C. 47,52,53 Since, below 200 8C, no weight loss was observed for the present synthesized PU, it can be concluded that there is no significant number of biuret and allophanate linkages in the present PU. Hence, the present PU exhibited more thermal resistance than others reported in the literature.…”

Section: Thermal Propertiesmentioning

confidence: 75%

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Semi‐IPN of biopolyurethane, benzyl starch, and cellulose nanofibers: Structure, thermal and mechanical properties

Haque

Oksman

2016

J of Applied Polymer Sci

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The aim of this study was to develop bionanocomposites of biopolyurethane (PU), benzyl starch (BS), and cellulose nanofibers (CNF) with semi-interpenetrating polymer network (S-IPN) structure of improved properties. Morphology, thermal and mechanical properties of S-IPN blends and nanocomposites were studied and compared with the neat polymers. Microscopy study showed that PU and BS were partially miscible as well as CNF were dispersed in both PU and BS phases in the nanocomposites. Dynamic mechanic thermal analysis demonstrated that BS decreased the tan d peak of the PU while CNF increased it . The positive shifting of tan d peak in the S-IPN nanocomposite also indicated the presence of CNF in the PU phase. It was also noticed that S-IPN nanocomposite displayed two tan d peaks at higher temperature, indicating molecular interaction among BS, PU, and CNF. Furthermore, the S-IPN nanocomposites displayed significantly higher E-modulus and tensile strength compared with the neat PU. V C 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43726.

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Section: Resultsmentioning

confidence: 68%

Section: Thermal Propertiesmentioning

confidence: 75%

Semi‐IPN of biopolyurethane, benzyl starch, and cellulose nanofibers: Structure, thermal and mechanical properties

Haque

Oksman

2016

J of Applied Polymer Sci

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“…In all the cases, the absence of the peak in the range of 2000 to 2300 cm -1 indicates that all the isocyanate groups had reacted. In addition, the combination of urethane carbonyl (NH-CO-O) and esteric carbonyl (CO-O) vibrations at 1735 cm -1 [16] and the stretching vibrations of the C-O-C band at 1176 cm -1 were observed. This was the strong evidence for the formation of urethane linkage.…”

Section: Fourier Transform Infrared Spectroscopy Analysismentioning

confidence: 99%

Synthesis and Characterization of Polyols from Refined Cooking Oil for Polyurethane Foam Formation

et al. 2012

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In this study, synthesized polyols from refined cooking oil, one of the ingredients in producing polyurethane (PU) foam, were investigated. The effects of reaction time, pH and type of solvents used on the properties of the polyols were characterized by using gas chromatography mass spectrometry (GC-MS), Fourier transform infrared (FTIR) spectroscopy and gel permeation chromatography (GPC). Further studies were carried out by using the synthesized polyols in combination with other chemicals for PU foam formation. The characterizations of the PU foams were performed through chemical, morphological and thermal analyses. The results showed that the polyols were synthesized successfully from refined cooking oil by using epoxidation and the hydroxylation process. 50% of the unsaturated fatty acids in the refined cooking oil were converted to saturated fatty acids and hydroxyl compounds as the reaction time increased up to five hours. However, the chemical contents in the polyols did not show significant changes as the pH value increased from pH3 to pH7. Using different types of solvent in the process showed that the hydroxyl content of the polyols ranged between 57 to 69 mg KOH/ g, with MtruēW in the range of 15325 to 19320 g mol-1. The results also revealed that not all the synthesized polyols were suitable for PU foam formation. It is recommended in this study that the minimum hydroxyl content and molecular weight of the synthesized polyol required for PU foam formation is 69 mg KOH/ g and 19320 g mol-1 respectively. The properties of PU foam are highly dependent on the polyol and the water (blowing agent) content.

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“…Entre os grupos presentes na estrutura do PU, os alofanatos e os biuretos, os quais são formados entre as ligações uretano e uréia com grupos isocianatos presentes na estrutura do PU, são menos estáveis e, geralmente, decompõem primeiro e a degradação térmica desses grupos pode ocorrer entre 170 e 180 °C [28,41,42]. As ligações uretano e uréia podem sofrer degradação térmica por volta de 270 °C, seguidas pelos grupos isocianurato s [41].…”

Section: Análise Termogravimétricaunclassified

Reciclagem química de espumas de poliuretano

Ribeiro¹,

Paoli²

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Fevereiro de 2010ii v "O mundo é como um espelho que devolve a cada pessoa o reflexo de seus próprios pensamentos. A maneira como você encara a vida é que faz toda diferença." Luiz Fernando Veríssimo vii Dedico este trabalho aos meus pais, que me ensinaram a lutar pelos ideais com sabedoria, perseverança, honestidade e dignidade.Ao Aloizio Junior, pelo amor, dedicação e paciência nestes anos ao meu lado.A toda família, pelo apoio, pela motivação e pela compreensão. ix AGRADECIMENTOSAos meus pais Alexandre e Rosa, pelo carinho e pelos exemplos deixados.À minha família, cada um que, à sua maneira esteve ao meu lado, e me deu bastante apoio

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Untitled

Cited by 4 publications

References 3 publications

Semi‐IPN of biopolyurethane, benzyl starch, and cellulose nanofibers: Structure, thermal and mechanical properties

Semi‐IPN of biopolyurethane, benzyl starch, and cellulose nanofibers: Structure, thermal and mechanical properties

Synthesis and Characterization of Polyols from Refined Cooking Oil for Polyurethane Foam Formation

Reciclagem química de espumas de poliuretano

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