First Stage Of Degradation Research Articles

The promotion mechanism of Mn on the catalytic degradation of benzene by H2O2 on Cu surface: The simultaneous enhancement of OH generation and benzene oxidation by ·OH

It is a promising technology to degrade benzene by using the strong oxidizing ·OH produced by H2O2 decomposition. However, in practical engineering, the low yield and utilization rate of ·OH affect the degradation effect, and the development of new catalysts is the key to solve this problem. The effects of Mn-doped on the decomposition of H2O2 on the surface of Cu (Mn-Cu) to obtain ·OH were studied by combining density functional theory, including the adsorption and decomposition characteristics of H2O2 and the ineffective consumption reaction of ·OH on the surface. At the same time, the specific reaction process between benzene and · OH on the surface was studied, and the effectiveness improvement of various reactions on the surface of Mn-Cu was analyzed in detail. It is found that the charge transfer between Mn and Cu forms positive and negative charge centers on the surface, the O-O bond break of H2O2 molecules that promote adsorption on the surface occurs homolysis, and has a significant inhibitory effect on the ineffective consumption reaction between ·OH and H2O2 molecules and ·HO2, thus improving the yield and utilization of ·OH. At the same time, the reaction energy barrier between ·OH and benzene was significantly reduced, the energy barrier of the first stage of degradation was reduced from 206.86 kJ/mol to 27.02 kJ/mol, and the degradation efficiency of benzene was greatly improved. And the effect improvement was verified through degradation experiments. The degradation rate of Mn-Cu surface is higher than that of Cu surface at all stages, and the final degradation rate can reach about 89%. By clarifying the above reaction mechanism, it provides theoretical support for the development of new catalysts.

Thermal, Morphological, and mineralogical characterization of ancient potsherds: Insights from activation energy and degradation profiles

The six representative potsherds sourced from the excavated Buddhist site of Udayagiri, Odisha, in eastern India, were studied using analytical characterization techniques of X-ray diffractometry (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), thermogravimetry (TG-DTG), and a porosity study. The analysis has unveiled the clay composition, firing temperatures, and environment along with internal morphology of these potsherds after firing process. The thermal behavior of the pottery samples was meticulously examined and degradation profiles depicted through TG-DTG curve. The activation energy of potsherds was calculated using the Horowitz and Metzger equation, shedding light on the various stages of degradation. Notably, the calculated activation energies for the first stage of degradation ranged from 5.78 to 16.64 kJ/Mole, while for the 2nd/3rd stage degradation, the range was between 2.59 KJ/Mole to 8.38 KJ/Mole, underlining the intricate firing processes involved. This research has successfully estimated firing temperatures across different environmental conditions, spanning from 450 to 900 °C. The pottery fragments were categorized into two distinct varieties following a comprehensive analysis of firing temperature, inclusions, morphological characteristics, firing conditions, and degradation profiles. The multifaceted approach employed in this study has contributed significantly to our understanding of these potsherds' composition and their firing profile.

Production of rigid bio-based polyurethane foams from sugarcane bagasse

Current polyurethane products (PUs) rely heavily on two feedstocks that are primarily petroleum-derived, leading to significant social and environmental concerns. This study examined utilisation of the sugarcane bagasse-based-bio-oil produced from hydrothermal liquefaction (HTL) with glycerol co-solvent, as an alternative resource to produce bio-based PU foams. The influences of HTL conditions such as glycerol loading (0–50 wt%) and alkaline catalyst concentration (0.05–1 M K2CO3) as well as the loading of bio-oil replacing polyol in the PUs formulation (0–100 wt%) on the thermal stability and mechanical properties of PU foams are investigated in this work. The FTIR results confirm the successful reaction of isocyanate and bio-oil’s hydroxyl groups, producing urethane linkages. Although increasing the amount of bio-oil as polyol (25–100 wt%) in PUs formulation remarkably reduced the thermal stability of the produced foams in the first stage of degradation (150–230 ℃), it conversely increased in the second stage (350–450 ℃). The PU foams incorporated with 50 wt% bio-oil afforded a remarkable compressive strength of 280–450 kPa. This study demonstrates insights into synthesizing sustainable bio-based PUs from agricultural waste biomass, thereby providing a fundamental understanding of the practical application of green PU foams.

Digestibility Kinetics of Polyhydroxyalkanoate and Poly(butylene succinate-co-adipate) after In Vitro Fermentation in Rumen Fluid.

Using polyhydroxyalkanoate (PHA) materials for ruminal boluses could allow for longer sustained release of drugs and hormones that would reduce administration time and unneeded animal discomfort caused by continuous administration. The objective of this study was to determine ruminal degradability and kinetics of biodegradable polymers and blends. A proprietary PHA-based polymer, poly(butylene succinate-co-adipate) (PBSA), PBSA:PHA melt blends, and forage controls were incubated in rumen fluid for up to 240 h. Mass loss was measured after each incubation time, and digestion kinetic parameters were estimated. Thermogravimetric, differential scanning calorimetry, and intrinsic viscosity analyses were conducted on incubated samples. Generally, across treatments, mass loss was significant by 96 h with a minimum increase of 0.25% compared to 0 h but did not change thereafter. Degradation kinetics demonstrated that polymer treatments were still in the exponential degradation phase at 240 h with a maximum disappearance rate of 0.0031 %/h. Melting temperature increased, onset thermal degradation temperature decreased, and intrinsic viscosity decreased with incubation time, indicating structural changes to the polymers. Based on these preliminary findings, the first stage of degradation occurs within 24 h and PHA degrades slowly. However, further ruminal degradation studies of biodegradable polymers are warranted to elucidate maximum degradation and its characteristics.

Influence of Urbanization on Patterns of Variability of Mytilus galloprovincialis Populations

Urbanization is currently one of the most widespread disturbances urgently requiring empirical data regarding its effects on coastal ecosystems. The aim of this study was to compare patterns of variability in populations of the Mediterranean mussel, Mytilus galloprovincialis, between urban and non-urban intertidal rocky shores, over a temporal scale of 12 months and multiple spatial scales (from cm to 10 s of km). For this, variance components associated with percentage cover, spat and total density, condition index, shell length and clump thickness of mussels were compared. Different patterns emerged depending on the response variable and the spatial and temporal scale. There was in general, a higher variability in urban than in non-urban shores, particularly for shell length, spat and total density that can be interpretated as a first stage of degradation, before noticing changes in mean values of these variables. Moreover, the most relevant scales of variability of total and spat density changed with urbanization (10 s of km in urban; 10 s of cm/m in non-urban). Results highlight the need for adopting proper management plans that should include the relevant spatial and temporal scales of variability; otherwise, they will fail in ameliorating urbanization effects on intertidal ecosystems.

Polymethyl Methacrylate/Polypropylene Blends Loaded with Graphene and Clay: Morphology, Mechanical Properties and Thermal Stability

In the research described here immiscible polymer blends based on amorphous poly(methyl methacrylate) (PMMA) and semi-crystalline polypropylene (PP) were produced via a melt-mixing method. The effects of the addition of graphene and clay nanoparticles on the compatibility and properties of the blends were investigated. Scanning electron microscopy results showed that the neat blends at all compositions were severely phase separated and a droplet-in-matrix morphology was attained. Introduction of graphene and clay caused the compatibility of the blends to be highly enhanced and, thus, a finer and more uniform morphology was obtained for the nanocomposites. Based on the morphology results, it was found that graphene had more affinity toward the PP phase and clay was more compatible with PMMA. This hypothesis was further proved via mechanical analysis and thermogravimetric analysis (TGA) results. The toughness of the neat blends was increased upon increasing the PP content; however, it was reduced for all the nanocomposites relative to the blend of the same polymer composition. The thermal stability of the blend at a composition of 70/30 PMMA/PP was improved via addition of clay and graphene. The first stage of degradation (PMMA) was shifted to higher temperatures once clay was added to the system while the second stage of degradation (PP) was impeded upon addition of graphene.

Thermal degradation of POSS-containing nanohybrid linear polyurethanes based on 1,6-hexamethylene diisocyanate

Synthesized from 1,6-hexamethylene diisocyanate (HDI), 1,4-butanediol (BDO), poly(tetramethylene)glycol (PTMG), and propanediolisobutyl-POSS (PHI‑POSS) nanohybrid polyurethanes (PU) were examined by TG/FTIR/MS coupled method to determine the mechanism of thermal improvement caused by POSS addition. The measurements were made in both; inert and oxidizing atmosphere for composites containing 0, 6, and 10 % of PHI-POSS. Depending on the concentration of additive, and the surrounding atmosphere we noticed from 5 to 15 °C improvement on different stages of degradation. Among the released gases, mostly tetrahydrofuran (THF), butanediol (BDO), and HDI were recorded, as well as various PTMG-derived ethers and alcohols formed during the depolymerization of segments present in the amorphous phase, as well as amines and amides as decomposition products of segments in the crystalline phase. Interestingly, the release of formates and formaldehyde before the first stage of degradation was observed in the oxidizing atmosphere. The effect of POSS addition causes: (i) reduction of the number of hard domains intensifies the first stage of degradation, but simultaneously increases the onset and the temperature of the maximum rate of decomposition at different stages through preventing some rearrangements leading to breaking of chain, and (ii) formation under elevated temperature conditions of silica-rich char residues that act as a barrier for gas and mass transport.

Resolving Potential-Dependent Degradation of Electrodeposited Ni(OH)2 Catalysts in Alkaline Oxygen Evolution Reaction (OER): In Situ XANES Studies

The activation and degradation mechanism of Ni-LDH catalysts electrodeposited on low and high-density carbon papers for the oxygen evolution reaction (OER) in alkaline media was investigated using in situ X-ray absorption near-edge structure (XANES) spectroscopy coupled with CV cycles in a potential range of 0–0.9 V (vs Hg/HgO), which allowed proposing two-stage degradation mechanisms with respect to cyclic voltammetry (CV) cycles. The electrodeposited α-Ni(OH)2 is firstly transformed to γ-NiOOH as an active phase in OER. In the reducible potential region, however, γ-NiOOH was partially reduced to β-Ni(OH)2, isolating the rest, which is the first stage of degradation. In the following anodic potential region, β-Ni(OH)2 is readily converted to β-NiOOH, which is mostly reversible, but only a small portion of β-NiOOH is overcharged to unstable γ-NiOOH, being responsible for the second stage degradation. It was noted that Ni(OH)2 catalysts electrodeposited on a low-density carbon paper (Ni-LC) underwent a severe degradation in the first stage, losing at least 56.9 % current density at 0.65 V (vs Hg/HgO), followed by a steady degradation in the second stage, while the use of a high-density carbon substrate (Ni−HC) effectively improved redox stability, maintaining a minimal loss of overpotential less than 5%, particularly with the second stage degradation being negligible even under potential changes, providing an important insight into designing durable and active Ni-LDH catalysts for the OER.

Thermal resistance and mechanical stability of tungsten oxide filled polymer composite radiation shields

The influence of tungsten oxide on thermal and mechanical properties of Isophthalic polyester was studied in detail. Ultrasonication technique was successful in dispersing WO3 filler particles upto 40 wt% into the polymer matrix and was confirmed through the Scanning Electron Microscopy technique. The mechanical strength of the composites was found to increase with increase in the WO3 content and is acting as a reinforcer. About 77.4%, 65.4% and 7–8 times increase was observed in tensile, flexural and compressive strength respectively with respect to pristine. The thermogram of the composites reveal two stages of degradation. Maximum weight loss was observed in the first stage of degradation in almost all the composites. The initial degradation temperature of the composites range from 151 °C–226 °C. Activation energy was estimated using Horowitz–Metzger kinetic theory and was found to range from 25.31 to 78.58 kJ/Mol. The 50 wt% WO3 filled composite exhibits excellent thermal stability and mechanical strength. Thus, WO3 filler particles were successful in enhancing the thermal and mechanical strength of Isophthalic polyester.

Physicochemical Studies on Some Coordination Biopolymer Compounds: Kinetics of Thermal Degradation and Heterogeneous Chemical Equilibrium of Ion Exchange for Coordination Biopolymer Zirconium (IV)- Alginate Complex

Thermogravimetry (TG) and differential thermogravimetry (DTG) techniques have been applied for studying the kinetics of thermal degradation of coordination biopolymer zirconium (IV)- alginate complex in static air. The DTG curves indicated the presence of a series of thermal peaks associated with three distinct stages of TG curves, i.e. three stages of degradation were observed. The first stage of degradation was corresponding to the dehydration of four coordinated water molecules in the first step, followed by degradation of the formed dehydrated compound in the other two following stages. The kinetic parameters were computed by a set of different models and a tentative degradation mechanism consistent with the kinetic observations is discussed. In addition, the heterogeneous chemical equilibrium for ion exchange process of Zr4+ counter ions chelated in the biopolymer coordination complex by exchangeable H+ ions of acid electrolyte have been investigated by using both the complexometric and titrimetric techniques. The kinetic and thermodynamic parameters have been evaluated and discussed in terms of the complex stability related to the strength of chelation and geometrical structure of coordination complex.

Effect of environmental conditions on the durability of polycarbonate for the protection of cultural heritage sites.

Polycarbonate is a good material for covering and protecting cultural heritage sites because of its durability, mechanical properties, and transparency. However, polycarbonate degrades under environmental weathering with a significant decrease of physical and mechanical properties and loss of transparency. In this work, the contemporary presence of ultraviolet irradiation and different temperature and moisture conditions have been taken into account to study the environmental degradation of this polymer with regard to its mechanical and optical properties. The photo-oxidation reactions cause a decrease in the molecular weight and the formation of many oxygenated species. The hydrolytic scission, instead, gives rise to a remarkable reduction in the molecular weight. These two different degradation mechanisms do not seem interconnected because at the lowest degradation temperature and high humidity levels, the reduction of the molecular weight is more pronounced than that observed at the highest temperature but at a lower humidity level. Transparency decreases with the degradative processes, but even after severe degradation the loss of transparency is only about 10%. The yellowness index increases during the first stages of degradation, which has been attributed to the fast formation of carbonyl groups due to photo-oxidation.

Electrochemical Stripping of Atomic Oxygen on Single-Crystalline Platinum: Bridging Gas-Phase and Electrochemical Oxidation.

To understand the interaction between Pt and surface oxygenated species in electrocatalysis, this paper correlates the electrochemistry of atomic oxygen on Pt formed in the gas phase with electrochemically generated oxygen species on a variety of single-crystal platinum surfaces. The atomic oxygen adsorbed on single-crystalline Pt electrodes, made by thermal dissociation of molecular oxygen, is used for voltammetry measurements in acidic electrolytes (HClO4 and H2SO4). The essential knowledge of coverage, binding energy, and surface construction of atomic oxygen is correlated with the charge, potential, and shape of voltammograms, respectively. The differences of the voltammograms between the oxide made by thermal dissociation of molecular oxygen and electrochemical oxidation imply that atomic oxygen is not an intermediate of the electrochemical oxidation of Pt(111). The reconstruction of (100) terrace and step and the low-potential stripping of atomic oxygen on (111) step site provide insight into the first stages of degradation of Pt-based electrocatalysts.

Surface effects on the degradation mechanism of bioactive PDMS-SiO2-CaO-P2O5 hybrid materials intended for bone regeneration

The purpose of this work is to study the dissolution mechanism of SiO2-based bioactive hybrid materials containing both CaO and P2O5 in their structures and to determine the influence of apatite crystallization over the surface features of the hybrids during degradation. Hybrid materials were synthesized using sol–gel method. Tetraethoxysilane (TEOS), hydroxyl terminated polydimethylsiloxane (PDMS), Ca(NO3)2·4H2O, and triethyl phosphate (TEP) were used as reactants. The degradation and bioactivity of the hybrid materials were tested by soaking the specimens into simulated body fluid (SBF). Raman spectroscopy, tensiometry and N2 adsorption/desorption curves were used to measure the changes during the degradation experiments. Several mathematical approaches have been taken to analyze the results. The growth of an apatite layer on the surface of SiO2-modified PDMS-P2O5-CaO hybrid materials occurs together with degradation of the silica-based matrix. The dissolution kinetics depends upon the composition of the material. It varies from a surface-driven mechanism in the case of low-P2O5 samples to a degradation path which fits into a Weibull type kinetic model, typical of matrix dissolution processes in materials enriched in P2O5. During degradation, the surface parameters, fractal constant and anisotropy of the pores were determined. The slight increase of the fractal constant in low-containing P2O5 materials suggests the formation of a homogeneous silica-like layer in the first stage of degradation, which also works as anchoring nucleus for subsequent apatite formation. In all the cases, the degradation leads to ink-bottle shaped pores, increasing their volume as degradation occurs, but keeping their neck shape.

Photocatalytic degradation of the herbicide clopyralid: kinetics, degradation pathways and ecotoxicity evaluation

AbstractBACKGROUNDPhotocatalytic decomposition and mineralization of the herbicide clopyralid in aqueous solutions has been studied, aiming at an extended kinetic analysis, the elucidation of potential degradation pathways and the determination of ecotoxicity.RESULTSThe pseudo‐first‐order degradation kinetics was studied under different operational conditions, such as type of photocatalyst, catalyst loading, initial pH and hydrogen peroxide (H2O2) concentration. The degradation rates proved to be strongly influenced by these parameters. Organic chlorine and nitrogen were easily converted into inorganic in the presence of TiO2 P25, resulting in 90% conversion in both cases within 180 min of illumination, while conversion was enhanced in the presence of H2O2. Ten possible transformation products were identified by means of LC‐DAD‐ESI/MS analysis. Acute toxicity profiles using marine bacteria Vibrio fischeri showed an increasing trend during the first 60 min of illumination, which thereafter, progressively decreased.CONCLUSIONSIntermediates were formed mainly through pyridine ring transformation, dechlorination and decarboxylation reactions. The increasing trend in ecotoxicity at the first stages of degradation could be attributed to the progressive formation of intermediates more toxic than the parent molecule, or due to synergistic effects among the transformation products. © 2015 Society of Chemical Industry

Effect of styrene addition on thermal properties of epoxy resin doped with carbon nanotubes

The paper concerns thermal properties of epoxy resin doped with carbon nanotubes (CNTs) used as a matrix for Carbon Fiber Reinforced Polymer (CFRP) composites. The aim of this work was to determine the influence of styrene addition on thermal properties of epoxy resin/CNT nanocomposites. CNTs, supplied by Nanocyl, were dispersed in epoxy matrix using three roll millings. In order to dilute epoxy/CNT mixture, to make it useful for hand lay‐up method of CFRP fabrication, three different weight amounts of styrene were tested. Scanning electron microscopy was used for both CNT dispersion control and epoxy/CNT laminates structure evaluation. Glass transition temperature and thermal stability were determined. Fourier transform infrared spectroscopy (FTIR) was used for chemical structure verification. Thermal diffusivity of epoxy doped with carbon nanotubes, as well as CFRP doped with carbon nanotubes, was measured at four temperatures. Rheological tests were performed, and viscosity and storage and loss modulus were measured. From a modulus crossover point, gel time was determined. Scanning electron microscopy observations proved uniform dispersion of CNTs and reduction of voids and/or air bubbles amount as an effect of styrene addition. Decrease of thermal stability in the first stage of degradation is observed, and a decrease of glass transition temperature with an increase of styrene amount is noticed. For a small amount of styrene, thermal conductivity increases, while it starts to decrease when measured for a higher temperature. Viscosity decreases and gel time increases with the increase of styrene amount. Copyright © 2015 John Wiley & Sons, Ltd.

FTIR Study of the Impact of PC[60]BM on the Photodegradation of the Low Band Gap Polymer PCPDTBT under O-2 Environment

The photodegradation of the low band gap polymer poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b′]dithiophene)-alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT) during irradiation under white li...

FTIR Study of the Impact of PC[60]BM on the Photodegradation of the Low Band Gap Polymer PCPDTBT under O2 Environment

The photodegradation of the low band gap polymer poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b′]dithiophene)-alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT) during irradiation under white light (AM 1.5 conditions) has been studied in pristine polymer films as well as in blend films with [6,6]-phenyl C61 butyric acid methyl ester (PC[60]BM). In order to gain insight into the degradation process, FTIR spectroscopy has been used to follow the evolution of different subunits of the polymer and to probe the chemical product formation. In contrast to other polymers, not the alkyl side chains but the π-conjugated system is preferentially oxidized during the first stages of degradation. Furthermore, it has been shown that the subunits of the polymer backbone are differently affected by the degradation. Blending the polymer with PC[60]BM leads to a significantly larger impact on the stability of the cyclopentadiene group compared to the benzene ring of the benzothiadiazole group.

Thermal degradation studies of poly(urethane–siloxane) thermosets based on co-poly(dimethyl)(methyl, 3-glycidoxypropyl)siloxane and epoxy-terminated urethane oligomer

Abstract A series of crosslinked hybrid poly(urethane–siloxane) networks based on comb-like structure co-poly(dimethyl)(methyl, 3-glycidoxypropyl) siloxane, epoxy-terminated urethane oligomer cured with diethylenetriamine, were obtained. The samples were submitted to thermal stability investigations at non-isothermal conditions in nitrogen and air. The thermal degradation behavior was investigated by evolved gas analysis, using coupled TG-FTIR technique. The kinetic parameters of the degradation process were determined both by isoconversional methods of Friedman and Kissinger–Akahira–Sunose as well as by model fitting multivariate non-linear regression method. It was observed that the thermal stability of the poly(urethane–siloxane) thermosets depends on the siloxane content. The first stage of degradation is associated with urethane degradation and the second with decomposition of polyoxytetramethylene and siloxane moieties. The best fit of the f ( α ) function with the experimental data was found for two-step degradation mechanism.

Study of the degradation of a new PLA braided biomaterial in buffer phosphate saline, basic and acid media, intended for the regeneration of tendons and ligaments

The purpose of this study was to evaluate the effects of hydrolytic degradation on the properties of a PLA hollow braid designed as a new concept of biodegradable prosthesis for the regeneration of tendons and ligaments. The main function of the braided material is to bear mechanical loads while it is being replaced by the newly-generated tissue. The kinetics of braided material degradation is thus an important factor in determining the success of the product. In order to study this mechanism, PLA braid was subjected to a 12-month degradation process at 37 °C in PBS at pH 7.4 (to simulate the human physiological medium) and to accelerated degradation for one month in pH 12 and pH 3 solutions. Degradation of the braid subjected to hydrolysis was evaluated by weight loss, molecular weight distribution, mechanical properties, and calorimetric and morphologic analyses. The weight loss in a basic medium reached 21%, versus no significant change in the other media. Average molecular weight was reduced by approximately 50% in the three media, with loss of mechanical properties in all cases. The morphological changes were more evident in the PLA degraded in the basic medium. The crystallinity of the material increased at the first stages of degradation, regardless of the medium used.

Comparison of abiotic and biotic degradation of PDLLA, PCL and partially miscible PDLLA/PCL blend

Important differences between the biotic and abiotic hydrolysis of neat poly(dl-lactide) (PDLLA), poly(ε-caprolactone) (PCL) and a partially miscible PDLLA/PCL blend were found in this work. In abiotic conditions, the degradation process of all the studied specimens mainly proceeded by a bulk degradation mechanism and the diffusion rate of degradation products into the medium was relatively slow after 18weeks. The hydrophobic and semi-crystalline nature of PCL matrix made this polymer very stable against abiotic hydrolysis, whereas the degradation of PDLLA proceeded much faster due to its amorphous structure. In the first stages of degradation, PDLLA/PCL blend showed that its rich continuous PDLLA phase catalyzed the hydrolysis of the PCL phase, while the low content of PCL molecules partially delayed hydrolysis of PDLLA matrix. In compost, higher levels of degradation were found for all the studied systems during the first 12weeks of degradation, indicating an important effect of enzymes from microbes in compost on the degradation of PDLLA and PCL. Neat PDLLA and PDLLA/PCL blend seemed to degrade mainly by a bulk degradation mechanism, at least during the first 12weeks, such as previously observed in abiotic conditions, whereas PCL was preferentially degraded by a surface mechanism due to a very strong catalytic effect of microorganisms on its degradation. Contrary to the abiotic degradation, it was observed that the presence of a low content of PCL molecules in the rich-PDLLA blend did not interfere with the degradation trend of PDLLA in compost, and that the continuous PDLLA phase could partially suppress the biotic degradation of PCL molecules.In general, abiotic and biotic hydrolysis of PDLLA/PCL blends seems to be a complex phenomenon depending not only on the mixing ratio of both polymers but also on their crystallinity, miscibility level of polymer phases and the preferential degradation mechanism of each polymer component. If blends of PDLLA/PCL present a similar level of miscibility, it would be possible to estimate if the presence of the PDLLA or PCL phase could have a general catalytic or delaying role in the blend during the initial degradation stages, depending on which environment they are subjected to and the content of each polymer phase in the blend.