Cost-effective synthesis of environmentally benign materials on the basis of poly-3-hydroxybutyrate

Häberlein, H.; Seliger, H.; Kohler, Robert Ε.; Sulzberger, P.

doi:10.1590/s0104-14282005000200011

Cited by 8 publications

(5 citation statements)

References 13 publications

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“…Telechelic hydroxylated scl-PHA (scl-PHA-diols) with various molecular weights were obtained by the attack of hydroxyl groups of ethylene glycol to ester groups of scl-PHA [ 95 ]. PHBHV- b -PEG [ 96 ] and P3HB-based polyurethane block copolymer (PEU) [ 97 , 98 ] were synthesized by using the coupling reaction with scl-PHA-diols as hard segments and PEG as soft segments. It has been found that the block copolymers had higher thermal stability but lower melting point and crystallinity compared with those of scl-PHA-diols.…”

Section: Modification Of Scl-phamentioning

confidence: 99%

Modification and Potential Application of Short-Chain-Length Polyhydroxyalkanoate (SCL-PHA)

et al. 2016

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Abstract:As the only kind of naturally-occurring biopolyester synthesized by various microorganisms, polyhydroxyalkanoate (PHA) shows a great market potential in packaging, fiber, biomedical, and other fields due to its biodegradablity, biocompatibility, and renewability. However, the inherent defects of scl-PHA with low 3HV or 4HB content, such as high stereoregularity, slow crystallization rate, and particularly the phenomena of formation of large-size spherulites and secondary crystallization, restrict the processing and stability of scl-PHA, as well as the application of its products. Many efforts have focused on the modification of scl-PHA to improve the mechanical properties and the applicability of obtained scl-PHA products. The modification of structure and property together with the potential applications of scl-PHA are covered in this review to give a comprehensive knowledge on the modification and processing of scl-PHA, including the effects of physical blending, chemical structure design, and processing conditions on the crystallization behaviors, thermal stability, and mechanical properties of scl-PHA.

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Section: Modification Of Scl-phamentioning

confidence: 99%

Modification and Potential Application of Short-Chain-Length Polyhydroxyalkanoate (SCL-PHA)

et al. 2016

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“…Esse é, em muitos casos, o polímero que mais se aproxima de um eco-material ideal: é obtido de fontes renováveis, é facilmente biodegradado em solos de compostagem, é biorreabsorvível e biocompatível (pode ser usado em implantes médicos ou como substrato para crescimento celular) [5,6] . Infelizmente, a exploração comercial desse polímero tem sido dificultada devido a alguns fatores, como a alta cristalinidade, dificuldades de processamento e alto custo de produção.…”

Section: Introductionunclassified

Síntese e caracterização do copolímero poli(3-hidroxibutirato-co-ε-caprolactona) a partir de poli (3-hidroxibutirato) e poli(ε-caprolactona)

et al. 2010

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Resumo: O copolímero poli(3-hidroxibutirato-co-ε-caprolactona) foi sintetizado por transesterificação, a partir dos homopolímeros PHB e PCL, usando acetilacetonato de zircônio (IV), como catalisador, nas concentrações de 20, 50 e 80% de PHB em massa. Os copolímeros foram caracterizados por GPC, métodos espectroscópicos (RMN-1 H, RMN-13 C e IV-FT) e métodos térmicos (TG e DSC). A rota de síntese utilizada mostrou-se eficaz na síntese dos copolímeros P(HB-co-CL), os quais mostraram diminuição das cadeias poliméricas, apresentando Mw inferior a 24.000 Daltons. Todos os copolímeros obtidos são termicamente mais estáveis que o PHB e com menor cristalinidade que os homopolímeros de partida. Esses materiais são bons candidatos para utilização como biomateriais em matrizes para liberação controlada de fármacos ou mesmo como compatibilizante em blendas PHB/PCL. Palavras-chave: Biopolímeros, PHB, PCL, copolímero P(HB-co-CL).Synthesis and Characterization of the Copolymer Poly(3-Poly(3-Hydroxybutyrate)-co-ε-Caprolactone) from Poly(3-Hydroxybutyrate) and Poly(ε-Caprolactone) Abstract: In the present work, the copolymer poly(3-hydroxybutyrate-co-ε-caprolactone), P(HB-co-CL), was prepared by transesterification reaction from PHB and PCL. Zirconium (IV) acetylacetonate was used as catalyst and the copolymers were obtained in a wide range of compositions of PHB/PCL (20/80, 50/50, 80/20). These copolymers were characterized by GPC, FT-IR, 1 H-NMR, 13 C-NMR, TG, and DSC. The copolymers had weight average molecular weight less than 24.000 Daltons. All the systems were thermally more stable than PHB, showing lower crystallinity than the homopolymers. These materials are good candidates to be used as biomaterials, in drug release matrices, or even as PHB/PCL blends compatibilizers. Keywords: Biopolymers, PHB, PCL, P(HB-co-CL) copolymer. IntroduçãoDentre os vários materiais biodegradáveis, podemos citar a família dos poli(hidroxialcanoatos), PHAs, poliésteres provenientes de fontes renováveis, produzidos por uma ampla variedade de microrganismos como forma de reserva intracelular de carbono e energia [1] . Dentro da família dos PHAs destaca-se o poli(3-hidroxibutirato), PHB, que apresenta propriedades similares às do polipropileno [2] , sendo, porém, mais duro e quebradiço [3] . Tem crescido significativamente o interesse no estudo do PHB pelo seu variado potencial de aplicação, como em membranas [4] e na preparação de copolímeros, usando o hidroxivalerato, ou de compósitos com hidroxiapatita como forma de torná-lo menos quebradiço, no sentido de aumentar sua empregabilidade.O PHB é um poliéster termoplástico de origem microbiana sintetizado por diversas bactérias (por exemplo, Alcaligenes eutrophus e Rhodospirillum rubrum) que ocorrem naturalmente no solo. Esse é, em muitos casos, o polímero que mais se aproxima de um eco-material ideal: é obtido de fontes renováveis, é facilmente biodegradado em solos de compostagem, é biorreabsorvível e biocompatível (pode ser usado em implantes médicos ou como substrato para crescimento celular) ...

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“…1,2 Among numerous microbial polyesters, poly(3-hydroxybutirate-co-3-hydroxyvalerate) (PHBV) has been widely investigated as a biocompatible material suitable for pharmaceutical and medical applications. The literature reports the use of PHBV in tissue engineering and as drug delivery systems.…”

Section: Introductionmentioning

confidence: 99%

Physicochemical characterization of a hydrophilic model drug-loaded PHBV microparticles obtained by the double emulsion/solvent evaporation technique

Farago¹,

Raffin²,

Pohlmann³

et al. 2008

J. Braz. Chem. Soc.

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Micropartículas de poli(3-hidroxibutirato-co-3-hidroxivalerato) (PHBV) contendo um fármaco modelo hidrofílico, o cloridrato de metformina (MH), foram obtidas pela técnica de emulsão múltipla/evaporação do solvente. Diversas formulações foram preparadas, com o objetivo de investigar a influência de cada composição sobre a eficiência de encapsulação (EE). O resultado mais elevado de EE (9,76%) foi verificado quando da simultânea alcalinização e adição de NaCl na fase aquosa externa da formulação. O estudo por MEV das micropartículas revelou morfologia esférica e superfície rugosa. As intensidades de difração cristalina para as micropartículas contendo o MH foram menores do que aquelas observadas para a mistura física. Os resultados obtidos por IVTF sugerem que nenhuma ligação química foi formada entre o polímero e o fármaco. A avaliação por análise térmica indica o surgimento de interações favoráveis entre MH e PHBV. O estudo de liberação in vitro demonstrou a influência do PHBV no perfil de dissolução do MH.Poly(3-hydroxybutirate-co-3-hydroxyvalerate) (PHBV) microparticles containing a watersoluble model drug, metformin hydrochloride (MH), were obtained by a double emulsion/solvent evaporation technique. Several formulations were prepared in order to investigate the influence of each composition on the encapsulation efficiency (EE). The highest value of EE (9.76%) was obtained using simultaneously pH alkalinization and NaCl addition in the external water phase of the formulation. SEM study revealed a spherical morphology and a rough surface. The crystalline diffraction intensities for the MH-loaded microparticles were lower than that verified for the physical mixture. FTIR results suggested that no chemical bond between the polymer and the drug was formed. Also thermal analyses indicated a favorable interaction between MH and PHBV. In vitro drug release demonstrated the influence of the PHBV on the dissolution profile of MH. Keywords: PHBV, double emulsion/solvent evaporation technique, hydrophilic model drug, microparticles IntroductionBiodegradable polymeric materials have been received increasing interest due to several ecological and recycling aspects. 1,2 Among numerous microbial polyesters, poly(3-hydroxybutirate-co-3-hydroxyvalerate) (PHBV) has been widely investigated as a biocompatible material suitable for pharmaceutical and medical applications. The literature reports the use of PHBV in tissue engineering and as drug delivery systems. [3][4][5][6][7][8][9][10][11][12] Particularly, PHBV exhibits unique and interesting physicochemical features (e.g. piezoelectricity) in addition to their mechanical properties similar to the polypropylene and other widely used polyesters [e.g. poly(DL-lactide) and poly(DL-lactide-co-glycolide)]. 13 Moreover, PHBV is a less crystalline biopolymer than poly(3-hydroxybutirate), therefore an enhanced degradation rate is observed. 14 Farago et al. 1299 Vol. 19, No. 7, 2008 Several methods have been used to prepare microparticles, for both natural and synthetic polymers. 15...

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Cost-effective synthesis of environmentally benign materials on the basis of poly-3-hydroxybutyrate

Cited by 8 publications

References 13 publications

Modification and Potential Application of Short-Chain-Length Polyhydroxyalkanoate (SCL-PHA)

Modification and Potential Application of Short-Chain-Length Polyhydroxyalkanoate (SCL-PHA)

Síntese e caracterização do copolímero poli(3-hidroxibutirato-co-ε-caprolactona) a partir de poli (3-hidroxibutirato) e poli(ε-caprolactona)

Physicochemical characterization of a hydrophilic model drug-loaded PHBV microparticles obtained by the double emulsion/solvent evaporation technique

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