Biodegradable polymers samples

Altogether, the surface energy increase eorresponds to the mierobes adhesion inerease. The biodegradable polymer samples present an exception, while having a hydrophilie surface, they are still highly resistant to bacteria fouling. 

Soil biodegradation tests were done by taking a sandy loam as the source of the soil micro-organisms. All polymer samples were sieved through ASTM sieves and all the samples except poly-e-caprolactone, had a particle diameter between 90 and 53 pm, Poly-e-caprolactone sample was prepared dissolving a commercially... 

CO2, a blank compost inoculum without an additional carbon source (polymer sample) is simultaneously tested under the same conditions. The CO2 content of the exhaust air of both vessels is compared. After subtracting the CO2 evolution of the blank inoculum, the CO2 evolution related to the test polymer is monitored and plotted as a biodegradation curve (see Fig. 1). Finally, the activity of the compost inoculum in the controlled composting test is validated using a cellulose reference instead of the polymer. In Fig. 1, the biodegradation curve of Ecoflex is depicted. After 80 days, 90% of the theoretical CO2 evolution is reached. Thus, Ecoflex is ultimately biodegradable according to the ISO standard for compostable polymers (ISO 17088), which requires 90% of the theoretical CO2 evolution within 180 days. 

An area in which MTDSC could perhaps be more extensively used is in the field of biomaterials and biodegradable polymers, as the physical characteristics of these materials may be intimately associated with their functionality. An example of such a study is that of Cesaro et al. (64), in which poly(hydroxybutyrate), a biodegradable polymer that is a substrate for soil microorganisms, was studied in relation to the effect of preparation conditions on the degree of crystallinity. The authors used MTDSC to demonstrate that the glass transition could be clearly visualized for the quench-cooled systems but was also present for unquenched samples, indicating that there was an amorphous component to the polymer, irrespective of conditioning. 

The results of the weight changes of the polymer samples studied during biodegradation in compost and in sea water are presented in Table 3 and Table 4, respectively. 

Table 3. The weight losses of polymer samples after biodegradation in compost with active sludge ...

Polymer samples were subjected to soil degradation in a laboratory at a temperature 22-25°C. Samples in the form of a film thickness of 50 microns was placed in the soil to a depth of 1.5-2 cm. Biodegradation rate was assessed by evaluating the mass loss of the samples. Mass losses were fixed by weighing the samples on an analytical balance. 

The mixed solution is poured into a frame made of silicone material which is placed in liquid nitrogen. Then, the polymer sample is added to a mixture of water and ethanol and subjected to foaming for 24 h. After foaming, the sample is freeze-dried for 20 h to provide biodegradable dual pore polymer scaffolds. The overall porosity was about 98% which was analyzed by mercury porosimeter. 

Petrov et al. (2006) stndied porons biodegradable polymer microparticles (with PLGA, 51-62 kDa, 21 samples) designed as devices for drng delivery in depot formulations nsing NMR cryoporometry (with kQj=50 K nm) method. The main PSD peak for all samples was at 60-100 nm. There was no comparison of the NMR cryoporometry results with other methods. SEM images were of low resolution to analyze the porosity of polymer particles. 

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