Enzymatic degradation of radiation crosslinked poly(ε–caprolactone)

Darwis, Darmawan; Mitomo, Hiroshi; Enjoji, Taro; Yoshii, Fumio; Makuuchi, Keizo

doi:10.1016/s0141-3910(98)00005-6

Cited by 67 publications

(55 citation statements)

References 10 publications

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“…O PCL não foi recuperado do solo, degradou [20] , filmes de PP homopolímero tem cristalização mais acelerada do que na blenda de PP/PCL, o que se deve ao aumento na razão de nucleação e orientação das cadeias. Após os tratamentos, observou-se diminuição da cristalinidade do 1º pico (PCL) e aumento de cristalinidade no 2º pico (PP), sugerindo a degradação do PCL inclusive de finais de cadeias, na fase cristalina e reorganização das cadeias do PP [14] . Segundo Gonçalves et al [7] , o aumento de cristalinidade do PP pode ser causado devido a formação de novos cristais na fase amorfa ou a incorporação de moléculas em cristais pré existentes (Figura 4a e b).…”

Section: Medidas De âNgulo De Contato Dos Filmes Tratados Em Coluna Dunclassified

Biodegradação de filmes de PP/PCL em solo e solo com chorume

2010

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Resumo: Filmes de blenda de poli(ε-caprolactona) (PCL) e polipropileno (PP) foram obtidos por moldagem por compressão. O estudo da biodegradação de filmes de blendas de PP/PCL em solo e solo com chorume foi obtido pela evolução de CO 2 , perda de massa, ângulo de contato, microscopia eletrônica de varredura (MEV) e calorimetria exploratória diferencial (DSC). As análises de evolução de CO 2 mostraram que a biodegradação da blenda de PP/PCL em solo com chorume foi maior que a dos homopolímeros, sugerindo que os polímeros na blenda são mais suscetíveis à degradação, o que se deve à não interação entre PP e PCL. Os resultados também mostraram que os microrganismos do solo com chorume provocaram uma erosão superficial. Verificou-se que a biodegradação do PCL é inibida pelos microrganismos do chorume adicionados no solo. Palavras-chave: Polímeros sintéticos, polímeros biodegradáveis, solo, polipropileno, poli(caprolactona). Study of Biodegradation of PP/PCL Films in Soil and Soil with Leachate LandfillAbstract: Blend films of polycaprolactone (PCL) and polypropylene (PP) have been obtained by melt-pressing of both components. The biodegradation of PP/PCL blend films in soil and soil with leachate landfill has been assessed with measurements of evolution of CO 2 , weight loss, contact angle, scanning electronic microscopy (SEM) and differential scanning calorimetry (DSC). The respirometric tests showed that the PP/PCL biodegradation in the soil with leachate was higher than the homopolymers, suggesting that the polymers in the blend are more susceptible to biodegradation owing to the lack of interaction between PP and PCL. The results also showed that biodegradation due to microorganisms in the soil with leachate occurred by surface erosion. It was found that the PCL biodegradation is inhibited by the leachate microorganisms added in the soil.

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Section: Medidas De âNgulo De Contato Dos Filmes Tratados Em Coluna Dunclassified

Biodegradação de filmes de PP/PCL em solo e solo com chorume

2010

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“…These observations were confirmed by Soedergard. [15] More detailed studies on PCL irradiation were performed by Yoshii et al, who investigated the influence of temperature and oxygen on gelation doses and crosslinking yields, [16,17] and assessed the influence of irradiation on mechanical and optical properties, susceptibility to chemical, enzymatic and biological degradation, [17][18][19] processability, [20] and thermal stability. [17] Ohrlander et al [21] discussed the structures of radicals formed by irradiation on the basis of electron spin resonance (ESR) and thermoluminescence data.…”

Section: Introductionmentioning

confidence: 99%

Poly(ε‐caprolactone) Biomaterial Sterilized by E‐Beam Irradiation

Filipczak

Woźniak

Ulański

et al. 2006

Macromolecular Bioscience

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The effects of ionizing radiation (electron beam) on poly(epsilon-caprolactone) (PCL) were studied by analyzing changes in viscosity-average and weight-average molecular weight and radius of gyration, and by performing sol-gel analysis and swelling tests. Samples were irradiated under various conditions: solid and molten PCL in the presence or absence of air. The overall efficiency of crosslinking is higher for samples irradiated in the molten state than in the solid state, and is reduced in the presence of oxygen. Based on three kinds of experiments (molecular weight dependence on the dose in the pre-gelation region, sol-gel analysis, and swelling study), radiation-chemical yields of intermolecular crosslinking and scission were determined and are discussed in terms of the mechanism of radiation-induced reactions in PCL. Properties of the gels formed by high-dose irradiation and mechanical properties of irradiated PCL were analyzed. Irradiation causes an increase in the compression modulus of PCL. This process occurs at the pre-gelation stage and continues in the gel-containing system. We have demonstrated, for the first time, that irradiation of solid PCL is accompanied by a pronounced post-effect, which manifests itself by changes in the average molecular weight. EPR data indicate that this effect, at least in part, is caused by the presence of long-lived radicals trapped in the crystalline regions. Irradiation with the sterilizing dose does not cause a statistically significant change in the biocompatibility of PCL after subsequent storage for 79 d, as determined by preliminary osteoblast vitality tests.

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“…The temperature was set up to 50 8C, as an optimum temperature. [10] After reaction for a certain time the films were taken out from the tubes, then washed with distilled water and dried in vacuum to constant weight. The biodegradation was observed by measuring the ratio of weight loss to the initial weight of the sample.…”

Section: Enzymatic Degradationmentioning

confidence: 99%