In situ FTIR study on melting and crystallization of polyhydroxyalkanoates

Xu, Jun; Guo, Baohua; Yang, Rui; Wu, Qiong; Chen, Guoqiang; Zhang, Zeng-Min

doi:10.1016/s0032-3861(02)00615-8

Cited by 199 publications

(163 citation statements)

References 21 publications

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“…PHB spectrum (Figure 3a) exhibits C=O stretching at 1724 cm -1 and C-O stretching at 1283 cm -1 . These results are in good agreement with previous reports on FTIR data of PHB [47]. PANI-HCl spectrum (Figure 3b) exhibits band at 1573 cm -1 attributed to C=N stretching of the quinoid diimine unit (N=Q=N).…”

Section: Ftir Analysissupporting

confidence: 93%

Biodegradable conductive composites of poly(3-hydroxybutyrate) and polyaniline nanofibers: Preparation, characterization and radiolytic effects

Araújo¹,

Ferreira²,

Araújo³

2011

Express Polym. Lett.

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Poly(3-hydroxybutyrate) is a biodegradable polyester produced by microorganisms under nutrient limitation conditions. We obtained a biodegradable poly(3-hydroxybutyrate) composite having 8 to 55% of chemically in situ polymerized hydrochloric acid-doped polyaniline nanofibers (70-100 nm in diameter). Fourier transform infrared spectroscopy and X-rays diffractometry data did not show evidence of significant interaction between the two components of the nanocomposite, and polyaniline semiconductivity was preserved in all studied compositions. Gamma-irradiation at 25 kGy absorbed dose on the semiconductive composite presenting 28% of doped polyaniline increased its conductivity from 4.6*10-2 to 1.1 S/m, while slightly decreasing its biodegradability. PANI-HCl biodegradation is negligible when compared to PHB biodegradability in an 80 day timeframe. Thus, this unprecedented all-polymer nanocomposite presents, at the same time, semiconductivity and biodegradability and was proven to maintain these properties after gamma irradiation. This new material has many potential applications in biological science, engineering, and medicine

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Section: Ftir Analysissupporting

confidence: 93%

Biodegradable conductive composites of poly(3-hydroxybutyrate) and polyaniline nanofibers: Preparation, characterization and radiolytic effects

Araújo¹,

Ferreira²,

Araújo³

2011

Express Polym. Lett.

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“…Os espectros de PHB (Figura 1 e 2) e blenda (Figura 3) foram normalizados pela intensidade de absorbância de uma banda considerada como padrão interno em 1380 cm -1 , atribuída à deformação simétrica de grupos CH 3 [14,15,16] , e desconvoluídos pela função Lorentziana para obter melhor resolução das bandas (separação em picos) [17] .…”

Section: Resultado E Discussãounclassified

“…A Tabela 3 compara os índices carbonila de fase amorfa (1748 cm -1 ) e de fase cristalina (1719 cm -1 ) [15,16] dos filmes de PHB e da blenda de PP/PHB originais e biotratados em água do Rio Atibaia antes e após o descarte do efluente (valores extraídos das Figura 1c, d). Na Tabela 4 estão apresentados os índices de fase amorfa e cristalina do PHB, obtidos, respectivamente, dos valores de absorbância da banda em 1186 cm -1 atribuída ao estiramento simétrico de grupo C-O-C e da banda em 1230 cm -1 atribuída à conformação helicoidal de cadeia, em relação à banda de referência em 1380 cm -1 , mantida como padrão interno [14,16] .…”

Section: Resultado E Discussãounclassified

“…Na Tabela 4 estão apresentados os índices de fase amorfa e cristalina do PHB, obtidos, respectivamente, dos valores de absorbância da banda em 1186 cm -1 atribuída ao estiramento simétrico de grupo C-O-C e da banda em 1230 cm -1 atribuída à conformação helicoidal de cadeia, em relação à banda de referência em 1380 cm -1 , mantida como padrão interno [14,16] .…”

Section: Resultado E Discussãounclassified

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Biodegradação de filmes de polipropileno (PP), poli(3-hidroxibutirato) (PHB) e blenda de PP/PHB por microrganismos das águas do Rio Atibaia

Faria

Martins-Franchetti

2010

Polímeros

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Resumo: O propósito deste estudo é investigar a biodegradação de filmes de PHB, PP e blenda de PP/PHB (1:1) por microrganismos de águas de rio poluído que recebeu vários tipos de descartes, inclusive de refinaria de petróleo. Os filmes poliméricos foram obtidos por fusão do pó do material a 175 °C, prensados a 71,3 kgf.cm -2 e resfriados a 25 °C. Estes filmes foram mantidos em amostras de águas do rio poluído, coletadas antes e após o descarte do efluente da refinaria de petróleo e mantidas em estufa bacteriológica a 28 °C, durante 120 dias. As mudanças, causadas pela ação microbiana nos filmes, foram analisadas por medidas de perda de massa, infravermelho com transformada de Fourier (FTIR) e microscopia eletrônica de varredura (MEV). Os resultados provaram que a degradação do PHB ocorre tanto na sua fase amorfa como na cristalina, sendo mais significativa na água do rio que recebeu o efluente da refinaria de petróleo, contendo microrganismos reconhecidos como potencialmente capazes de degradar substâncias persistentes no meio ambiente. Palavras-chave: Biodegradação, PP, PHB, blendas, microrganismos, rio poluído. Biodegradation of Polypropylene (PP), Poly(3-hydroxybutyrate) (PHB) Films and PP/PHB Blend by Microorganisms from Atibaia RiverAbstract: The purpose of this study is to investigate the biodegradation of films made with PP, PHB and PP/PHB (1:1) blend caused by microorganisms from polluted river which received several types of waste, including an oil refinery effluent. The films were obtained by melting the powder from the material at 175 °C, pressed at 71.3 kgf.cm -2 and cooled at 25 °C. These films were kept in polluted river water samples, collected before and after the discarding of oil refinery waste, and they were kept in the bacteriological incubator at 28 °C for 120 days. The changes caused by microbial action on the films were analyzed by measurements of weight loss, Fourier transform infrared (FTIR) and scanning electronic microscopy (SEM). The results proved that PHB degradation occurs in amorphous and crystalline phases, being more significant in the river water which received refinery oil waste, containing microorganisms recognized as potentially capable to degrade recalcitrant substances in the environment. Keywords: Biodegradation, PP, PHB, blends, microorganisms, polluted river. IntroduçãoOs polímeros sintéticos tornaram-se importantes na sociedade porque podem substituir materiais como: papel, madeira, vidro e metal, solucionando grande número de problemas, quer na indústria, na agricultura, na medicina e em outras áreas. Isso se deve às características como: durabilidade, atoxicidade, baixo custo, facilidade para serem moldados, capacidade de serem reciclados e versatilidade de aplicação. O mercado de resinas plásticas tem aumentado ultimamente, significando uma expansão da indústria petroquímica, que movimenta a economia e gera empregos em diversos segmentos do setor [1,2] . Entretanto, o uso e o descarte indevidos dos materiais plásticos, aliados a sua resistência à degradação acabam g...

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“…It can be seen from Figure 2 that characteristic peaks of PHB at 3300-3700, 1700-1760, and 500-1500 cm À1 all appear in neat PHB and PHB-g-AA [32,33], but an extra peak at 1710 cm À1 assigned to ÀC=O as well as a broad OÀH stretching absorbance centered at 3265 cm À1 are observed for the modified PHB. Similar results have been reported elsewhere [34,35].…”

Section: Ftir Analysismentioning

confidence: 97%

Poly(3-hydroxybutyrate)/multi-walled carbon nanotubes nanocomposites: preparation and characterizations

Liao

2012

Designed Monomers and Polymers

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In this study, the poly(3-hydroxybutyrate)/multi-walled carbon nanotubes (PHB/MWNTs) nanocomposite was prepared by means of a melt blending method. To improve the compatibility/dispersability of MWNTs within the PHB matrix, the acrylic acid grafted poly(3-hydroxybutyrate) (PHB-g-AA) and the multihydroxyl functionalized MWNTs (MWNTs-OH) were used as alternatives. Based on the results of TEM micrographs, FTIR spectra, 13 C solid-state NMR spectra, XRD patterns, and thermal and mechanical characterizations, the PHB-g-AA/MWNTs-OH blend demonstrated dramatic enhancement in thermal and mechanical properties of PHB due to the formation of ester carbonyl groups through the reaction between carboxylic acid groups of PHB-g-AA and hydroxyl groups of MWNTs-OH. For example, with an addition of 1 wt.% MWNTs-OH, the increases in the initial decomposition temperature and the tensile strength at break were 75°C and 15.1 MPa, respectively. Finally, the optimal amount of MWNTs-OH was 1 wt.% because excess MWNTs-OH caused separation of the organic and inorganic phases and reduced their compatibility.

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In situ FTIR study on melting and crystallization of polyhydroxyalkanoates

Cited by 199 publications

References 21 publications

Biodegradable conductive composites of poly(3-hydroxybutyrate) and polyaniline nanofibers: Preparation, characterization and radiolytic effects

Biodegradable conductive composites of poly(3-hydroxybutyrate) and polyaniline nanofibers: Preparation, characterization and radiolytic effects

Biodegradação de filmes de polipropileno (PP), poli(3-hidroxibutirato) (PHB) e blenda de PP/PHB por microrganismos das águas do Rio Atibaia

Poly(3-hydroxybutyrate)/multi-walled carbon nanotubes nanocomposites: preparation and characterizations

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