Search results for "Hydrolytic degradation"
showing 10 items of 10 documents
Performance of polyester-based electrospun scaffolds under in vitro hydrolytic conditions: From short-term to long-term applications
2019
The evaluation of the performance of polyesters under in vitro physiologic conditions is essential to design scaffolds with an adequate lifespan for a given application. In this line, the degradation-durability patterns of poly(lactide-co-glycolide) (PLGA), polydioxanone (PDO), polycaprolactone (PCL) and polyhydroxybutyrate (PHB) scaffolds were monitored and compared giving, as a result, a basis for the specific design of scaffolds from short-term to long-term applications. For this purpose, they were immersed in ultra-pure water and phosphate buffer solution (PBS) at 37 °
Polymere ester von säuren des Phosphors, 3. Polymerisation des 2-Äthoxy-2-oxo-1,3,2-dioxaphospholans
1975
2-Athoxy-2-oxo-1,3,2-dioxaphospholan (1) wird durch verschiedene Alkoholate sehr schnell und in hoher Ausbeute zu Poly[oxy(athoxyphosphoryl)oxyathylen] (3) polymerisiert. Die Produkte sind hochviskos und farbols. Sie losen sich in Wasser, Alkoholen, Tetrahydrofuran, Dioxan, Methylenchlorid, Chloroform und Dimethylsulfoxid; unloslich sind sie in Ather und in Kohlenwasserstoffen. Polymerisationsgrade bis 83 (M = 12600) wurden gemessen. In wasriger Losung bei Raumtemperatur erfolgte auch nach Tagen kein merklicher hydrolytischer Abbau. Der mutmaslich anionische Polymerisationsmechanismus und mogliche Nebenreaktionen werden kurz diskutiert. 2-Ethoxy-2-oxo-1,3,2-dioxaphospholane (1) is polymeriz…
The Effects of Nanoclay on the Mechanical Properties, Carvacrol Release and Degradation of a PLA/PBAT Blend
2020
The formulation of polymeric films endowed with the abilities of controlled release of antimicrobials and biodegradability is the latest trend of food packaging. Biodegradable polymer (Bio-Flex®
Preparation, characterization and hydrolytic degradation of PLA/PCL co-mingled nanofibrous mats prepared via dual-jet electrospinning
2017
Abstract PLA/PCL co-mingled nanofibrous mats were prepared via multi-jet electrospinning. The concentration of PLA and PCL in the co-mingled mats were controlled by changing the flow rate of the two polymer solutions. The amount of PLA and PCL in the co-mingled nanofibrous mats was monitored by UV–Vis measurements through a colored dye added to PLA and by FTIR-ATR analysis. Morphology and mechanical properties of the nanofibrous mats were respectively examined by scanning electron microscopy (SEM) and tensile tests. Water contact angles measurements were also carried out in order to investigate the wettability of the materials. Finally, the hydrolytic degradation of the mats in buffer solut…
Beyond Biodegradability of Poly(lactic acid): Physical and Chemical Stability in Humid Environments
2017
International audience; Poly(lactic acid) (PLA) is the most traded biodegradable and biobased material. It is largely used as ecofriendly substitute of conventional plastics. Nevertheless, one of the main limiting factors is its water sensitivity. PLA reacts with water and is hydrolyzed during time, which determines its performance. Limited information related to the hydrolysis mechanism driven by water in vapor state is available in scientific literature. Literature is mainly focused on the effects of water in liquid state. This lack of information is of significant importance, since PLA interacts with water in both phases. This work was aimed to give a full depiction of the chemical and p…
Biopolymeric bilayer films produced by co-extrusion film blowing
2018
Abstract Biodegradable packaging promises a more environmentally friendly future. Nevertheless, a single biopolymer often lacks of some important properties. In order to contribute to this challenge, biodegradable bilayer films from poly(lactic acid) (PLA) and MaterBi® were prepared in this work and compared with monolayer films obtained with both the polymers. The prepared films were fully characterized through morphological, mechanical, thermal, chemical, optical and water contact angle analyses. Furthermore, the hydrolytic degradation of monolayer and bilayer films was studied by performing tests at three different pH. The morphological analysis revealed that PLA/MaterBi bilayer films sh…
Degradation and Recycling of Films Based on Biodegradable Polymers: A Short Review
2019
The environmental performance of biodegradable materials has attracted attention from the academic and the industrial research over the recent years. Currently, degradation behavior and possible recyclability features, as well as actual recycling paths of such systems, are crucial to give them both durability and eco-sustainability. This paper presents a review of the degradation behaviour of biodegradable polymers and related composites, with particular concern for multi-layer films. The processing of biodegradable polymeric films and the manufacturing and properties of multilayer films based on biodegradable polymers will be discussed. The results and data collected show that: poly-lactic…
BIODEGRADABLE BILAYER FILMS PREPARED BY CO-EXTRUSION
2017
The sensitivity for reducing packaging waste drove academic and industrial efforts to search compostable or biodegradable bio-sourced polymeric materials. Multilayer systems represent a suitable strategy to obtain the required properties and to improve biopolymer performance. The aim of the current work is the coextrusion film blowing of a biodegradable bilayer film PLA/MaterBi with the purpose to overcome the drawbacks of the individual components.
Hydrolytic degradation of PLA/Posidonia Oceanica green composites: A simple model based on starting morpho-chemical properties
2021
Abstract In this work, we studied the degradability of PLA-based biocomposites containing Posidonia Oceanica flour at different loading levels and aspect ratios. Hydrolytic tests were carried out in neutral (pH = 7.4) and alkaline (pH = 10) environment. Time-dependent evolution of some key features, including residual mass and solution uptake, was monitored, and correlated with the changes observed in both morphology and chemical structure of the matrix. The results pointed out that biocomposites degraded much faster than neat PLA in both conditions, up to lose 70% of their initial weight after 1000 h immersion. A complex mechanism was unveiled, evidencing the crucial role of the fillers, c…
Lignocellulosic fillers and graphene nanoplatelets as hybrid reinforcement for polylactic acid: Effect on mechanical properties and degradability
2020
Abstract This work investigates the effect of adding relatively low amounts of graphene nanoplatelets (GNP) to a biocomposite based on polylactic acid (PLA) and a lignocellulosic filler achieved by grinding Posidonia Oceanica leaves (Posidonia flour, PF). The ternary composites were prepared by melt extrusion and characterized from a morphological and mechanical point of view. Furthermore, hydrolytic degradation tests were performed under acidic, neutral and alkaline environment up to 900 h. Density measurements enabled to assess the degree of intraphase, i.e. the capability of polymer macromolecules to enter the voids of PF and a modified Halpin-Tsai model was presented and used to fit exp…