Study of PHBV/PBS blend and PHBV/PBS/sepiolite hybrid blend : preparation, physico- mechanical characterization and durability

Ce travail de recherche consiste à étudier les relations structure-propriétés de mélanges biopolymères à base de poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) et poly(butylène succinate) (PBS). Il est divisé en trois parties. La première partie est consacrée à l'étude des propriétés des mélanges PHBV/PBS préparés par voie fondue en fonction de la composition en termes de morphologie et de propriétés rhéologiques, mécaniques, thermiques et barrières. Les résultats obtenus ont été discutés par rapport aux polymères de base. La deuxième partie est consacrée à la compatibilisation des mélanges PHBV/PBS et l'amélioration des interactions à l'interface. Les effets de l'incorporation de la sépiolite à 5% en masse et du PHBV greffé par de l’anhydride maléique (PHBV-g-MA) à 5% en masse ont été étudiés en termes de changements morphologiques montrant un effet synergique entre le compatibilisant et la nanocharge sur les l’ensemble des propriétés des mélanges PHBV/PBS. Enfin, une étude sur le recyclage a été menée à travers une évaluation des effets du nombre de cycles d'extrusion sur les propriétés des matériaux. Elle révèle qu'après 6 cycles d'extrusion, la dégradation thermo-mécanique du PHBV est significativement réduite en présence du PBS.The main objective of this work was to study the structure-properties relationships of biopolymerblends based on poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and polybutylene succinate (PBS). The work was devised into three parts. The first part was devoted to the study of the properties of PHBV/PBS blends prepared by melt compounding at different weight ratio in terms of morphology and properties. The results obtained were discussed in terms of properties and compared with the neat polymers. The second part was devoted to the study of compatibility of PHBV/PBS blends aiming to improve the interactions at the interface between the two components. The effects of both sepiolite (5% wt.) and PHBV-g-MA (5% wt.) were studied in terms of properties. The results showed a synergistic effect between the compatibilizer PHBV-g-MA and the nanofiller sepiolite though an increase in thermal, mechanical and rheological properties. The last part dealing with the recyclability of PHBV/PBS through the study of the effects of repeated extrusion cycles on the properties of materials. The results showed that after 6 reprocessing cycles the thermo-mechanical degradation of PHBV is significantly reduced in the presence of PBS

Étude des mélanges PHBV/PBS et des mélanges hybrides PHBV/PBS/sépiolite : préparation, caractérisation physico-mécanique et durabilité

The main objective of this work was to study the structure-properties relationships of biopolymerblends based on poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and polybutylene succinate (PBS). The work was devised into three parts. The first part was devoted to the study of the properties of PHBV/PBS blends prepared by melt compounding at different weight ratio in terms of morphology and properties. The results obtained were discussed in terms of properties and compared with the neat polymers. The second part was devoted to the study of compatibility of PHBV/PBS blends aiming to improve the interactions at the interface between the two components. The effects of both sepiolite (5% wt.) and PHBV-g-MA (5% wt.) were studied in terms of properties. The results showed a synergistic effect between the compatibilizer PHBV-g-MA and the nanofiller sepiolite though an increase in thermal, mechanical and rheological properties. The last part dealing with the recyclability of PHBV/PBS through the study of the effects of repeated extrusion cycles on the properties of materials. The results showed that after 6 reprocessing cycles the thermo-mechanical degradation of PHBV is significantly reduced in the presence of PBS.Ce travail de recherche consiste à étudier les relations structure-propriétés de mélanges biopolymères à base de poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) et poly(butylène succinate) (PBS). Il est divisé en trois parties. La première partie est consacrée à l'étude des propriétés des mélanges PHBV/PBS préparés par voie fondue en fonction de la composition en termes de morphologie et de propriétés rhéologiques, mécaniques, thermiques et barrières. Les résultats obtenus ont été discutés par rapport aux polymères de base. La deuxième partie est consacrée à la compatibilisation des mélanges PHBV/PBS et l'amélioration des interactions à l'interface. Les effets de l'incorporation de la sépiolite à 5% en masse et du PHBV greffé par de l’anhydride maléique (PHBV-g-MA) à 5% en masse ont été étudiés en termes de changements morphologiques montrant un effet synergique entre le compatibilisant et la nanocharge sur les l’ensemble des propriétés des mélanges PHBV/PBS. Enfin, une étude sur le recyclage a été menée à travers une évaluation des effets du nombre de cycles d'extrusion sur les propriétés des matériaux. Elle révèle qu'après 6 cycles d'extrusion, la dégradation thermo-mécanique du PHBV est significativement réduite en présence du PBS

Recyclability assessment of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/poly(butylene succinate) blends: Combined influence of sepiolite and compatibilizer

International audienceBlends of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly (butylene succinate) (PBS) (50:50 w/w) were prepared by melt mixing. 5 wt% of compatibilizing agent, obtained by grafting of maleic anhydride onto PHBV, was used to improve the miscibility between the blend components. The influence of the presence of both sepiolite and compatibilizer was studied by evaluating the effect of repeated extrusion cycles (up to 6) on the morphology and the functional properties of materials. Changes in thermal, morphological, rheological and mechanical properties were investigated. All the results showed that PHBV is the more sensitive component towards recycling due to thermomechanical degradation, but PBS as well as sepiolite and compatibilizer play a stabilizing role on PHBV due to improved morphology. The mechanical characteristics measured at different scales remain more or less constant compared to the initial ones revealing the preservation of the mechanical properties of the different samples after reprocessing. This paper highlights a synergistic effect induced by the presence of both compatibilizer and sepiolite leading to an improved recyclability of the resulting materials compared to neat polymers. (C) 2017 Elsevier Ltd. All rights reserved

Synergistic effect of compatibilizer and sepiolite on the morphology of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/poly(butylene succinate) blends

Blends of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(butylene succinate) (PBS) with different PHBV/PBS weight ratios (100/0, 75/25, 50/50 and 0/100) were elaborated by melt mixing. The morphological investigation of the different samples, in comparison with that of neat PHBV and neat PBS, pointed out that PHBV/PBS blends form a biphasic system over the whole composition range. Low amount of compatibilizing agent (5 wt%), obtained by grafting maleic anhydride (MA) onto PHBV, i.e. PHBV-g-MA, was used for improving the miscibility between the two components of the blend. The incorporation of a fibrous filler as the sepiolite, easily dispersible in a polymer matrix, was also investigated. The morphology of the different blends as well as the evolution of their material properties were discussed in terms of the sepiolite and compatibilizing agent contents. The dispersion of PBS in the PHBV matrix markedly became finer with incorporation of sepiolite and PHBV-g-MA, due to enhanced interactions between the components. This paper highlighted a synergistic effect induced by the presence of both compatibilizer and sepiolite leading to an improved miscibility of the two blend components. The resulting properties were correlated with the morphology observed for the different blends. (C) 2016 Elsevier Ltd. All rights reserved