Jéssica da Silva Chagas^1,2, José Elson Soares Filho^1,2, Natália Fernanda Inocêncio Silva^1,2, Marcelo Massayoshi Ueki³, Eliton Souto de Medeiros^1,2, Renate Maria Ramos Wellen¹, Mauricio Pinheiro de Oliveira⁴, Gelsoneide da Silva Gois⁵, Yêda Medeiros Bastos de Almeida⁵, Amélia S. F. Santos^1,2,*

Journal of Renewable Materials, Vol.12, No.12, pp. 2079-2094, 2024, DOI:10.32604/jrm.2024.055361 - 20 December 2024

Abstract Poly(3-hydroxybutyrate) (PHB) is a biothechnological and biodegradable thermoplastic polymer from the polyhydroxyalkanoates (PHAs) family, whose chain regularity, high molecular weight, and physical and mechanical properties comparable to polypropylene (PP) are characteristics that have made PHB a prominent commercial bioplastic. Nevertheless, its susceptibility to thermal degradation and hydrolysis has limited many applications. To address the challenges associated with processing, a random copolymer of 95.86 mol% 3-hydroxybutyrate and 4.14 mol% 3-hydroxyvalerate (referred as PHB) was compounded without (neat PHB) and with 0.25, 0.5, 1, and 1.5 wt% of chain extender (Joncryl^®ADR 4368), consisting of multifunctional epoxy groups, and… More >

Kahina Iggui^1,2,*, Mustapha Kaci¹, Mohamed Mahlous³, Nicolas Le Moigne⁴, Anne Bergeret⁴

Journal of Renewable Materials, Vol.7, No.9, pp. 807-820, 2019, DOI:10.32604/jrm.2019.06778

Abstract In this paper, the effects of gamma irradiation on Cast poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and PHBV/Cloisite 30B (C30B) (3 wt%) bionanocomposite prepared by melt compounding, were evaluated at various doses, i.e., 5, 15, 20, 50 and 100 kGy at room temperature in air. Changes in molecular weight, morphology and physical properties were investigated. The study showed that the main degradation mechanism occurring in gamma irradiation in both Cast PHBV and C-PHBV/3C30B bionanocomposite is chain scission, responsible for the decrease of molecular weight. Differential scanning calorimetry (DSC) data indicated a regular decrease in crystallization temperature, melting temperature and… More >

Shanhong Duan^*, Ali Wu^†, Zhengyu Chen^‡, Yarong Yang^*, Liying Liu^*, Qi Shu^*

Oncology Research, Vol.26, No.5, pp. 713-723, 2018, DOI:10.3727/096504017X15016337254641

Abstract MicroRNAs (miRNAs) are small noncoding RNAs that are involved in human carcinogenesis and progression. miR-204 has been reported to be a tumor suppressor in several cancer types. However, the function and underlying molecular mechanism of miR-204 in cervical cancer (CC) are still unclear. In the present study, the expression level of miR-204 was measured using the qRT-PCR method in 30 paired CC clinical samples and in 6 CC cell lines. We found that the expression of miR-204 was significantly downregulated in CC tissues and cell lines compared to normal cervical tissues and cell line. miR-204… More >

Kahina Iggui^1,2,*,†, Mustapha Kaci², Nicolas Le Moigne¹, Anne Bergeret¹

Journal of Renewable Materials, Vol.6, No.3, pp. 288-298, 2018, DOI:10.7569/JRM.2017.634184

Abstract The effects of accelerated photooxidation on the molecular weight and thermal and mechanical properties of Cast PHBV and PHBV/Cloisite 30B (3 wt%) bionanocomposites are investigated herein. Through size exclusion chromatography (SEC) analysis, a significant decrease in both weight and number average molecular weights was observed for all irradiated samples over time, resulting from the chain scission mechanism. Differential scanning calorimetry (DSC) data indicated a decrease in degree of crystallinity and melting temperature after UV exposure, with the appearance of double melting peaks related to the changes in the crystal structure of PHBV. Thermal stability, tensile More >

G. El hajj Sleiman¹, G. Colomines¹, R. Deterre¹, I. Petit1, E. Leroy², S. Belhabib^1,*

Journal of Renewable Materials, Vol.6, No.3, pp. 270-276, 2018, DOI:10.7569/JRM.2017.634179

Abstract Poly(3-hydroxy butyrate)-co-(3-hydroxy valerate) (PHBV) is a biobased and biodegradable polyester. This semicrystalline bioplastic could be a good candidate for the replacement of some commodity plastics derived from oil. However, the control of the conditions of its processing in order to obtain optimal properties of the finished products remains a current research subject. The objective of this work is to better understand the crystallization under injection molding conditions by inline measurements during the process. We focused on the influence of two key processing parameters, namely, mold temperature and packing pressure. The modeling of inline temperature measurements More >

Enzo Alvarado-Cordero¹, Gabriela Montes de Oca-Vásquez², Reinaldo Pereira-Reyes², José Vega-Baudrit², Marianelly Esquivel-Alfaro^1*

Journal of Renewable Materials, Vol.5, No.3-4, pp. 323-331, 2017, DOI:10.7569/JRM.2017.634123

Abstract Biodegradable polymers from renewable resources are generating growing interest in the plastic industry because they have properties similar to synthetic polymers. Polyhydroxyalkanoates, mainly polyhydroxybutyrate (PHB), have mechanical and physicochemical properties very similar to their synthetic counterparts. This work explores the use of residual glycerol from the bioenergy industry for the production of PHB by Bacillus megaterium DSM 32. The glycerol works as a source of carbon and energy. Raw glycerol was purified with sulfuric acid in order to neutralize saponified fatty acids. The purification process generated three different phases. One of the phases was the… More >

Sudhakar Muniyasamy^1,2, Osei Ofosu^1,2, Maya Jacob John^1,2, Rajesh D. Anandjiwala^1,2*

Journal of Renewable Materials, Vol.4, No.2, pp. 133-145, 2016, DOI:10.7569/JRM.2016.634104

Abstract The present study investigates the mineralization of poly(lactic acid) (PLA) and poly(3-hydroxybutyrate-covalerate) (PHBV), and PLA/PHBV blend in compost and soil burial environments. The mineralization was assayed on the basis of carbon dioxide (CO2) release from the test materials incubated in compost and soil for a period of 200 days. The degradation was followed by means of fragmentation, thermogravimetric (TGA), FTIR spectroscopy and scanning electron microscopy (SEM) analyses. The results showed that PLA, PHBV and blend of PLA/PHBV achieved almost 90% biodegradation under composting conditions, while PHBV, PLA/PHBV blend and PLA respectively achieved only 35%, 32% More >

Estefanía Lidón Sánchez-Safont¹, Jennifer González-Ausejo¹, José Gámez-Pérez¹, José María Lagarón², Luis Cabedo^1*

Journal of Renewable Materials, Vol.4, No.2, pp. 123-132, 2016, DOI:10.7569/JRM.2015.634127

Abstract Novel biodegradable composites based on poly(3-hydroxybutirate-co-3-hydroxyvalerate) (PHBV) and different contents of purifi ed alpha-cellulose fi bers (3, 10, 25 and 45%) were prepared by melt blending and characterized. The composites were characterized by scanning electron microscopy (SEM), wide-angle X-ray scattering (WAXS) experiments, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanic analysis (DMA) and Shore D hardness measurements. Disintegrability under composting conditions was studied according to the ISO 20200 standard. Morphological results showed that high dispersion of the fi bers was achieved during mixing. Good adhesion on the fi ber-matrix interface was also detected by More >