Structure, morphology, and biodegradability of poly(ε‐caprolactone)‐based nanocomposites

Abstract

Biodegradable polycaprolactone/organoclay nanocomposites were prepared by solvent casting, using different amounts of filler and matrices differing by average molecular weight. Intercalated nanocomposites were obtained. The nanocomposites were characterized by wide-angle X-ray diffraction (WAXD) and small-angle Xray scattering (SAXS) methods. Negligible variations in the degree of crystallinity were detected by WAXD. The thickness of crystalline lamellae, measured by SAXS, increased in low molecular weight polymer nanocomposites with increasing clay amount; this effect was weakened in matrices with high molecular weight. Differential scanning calorimetry showed an inhibiting effect of clay on crystallization. The composites' ductility was largely increased, whereas stiffness was retained. After biodegradation in compost, in all samples, the degree of crystallinity was increased, meaning that the less ordered portion of the sample was preferentially degraded. Clay slowed down the biodegradation rate, coherently with the observed increase in the lamellar thickness due to the filler. This may offer a strategy for tuning the biodegradability by calibrating their semicrystalline framework. POLYM. ENG.

Electrospun nylon fibers for the improvement of mechanical properties and for the control of degradation behavior of poly(lactide)-based composites

“…47,53,54 However, the semicrystalline morphology of the samples, i.e., the quantity of amorphous material at disposal for degradation was not so different to explain such divergence because PLANY1.5 and PLANY2.5 had different degradation rates, but a similar degree of crystallinity. The morphology of the fiber/matrix assembly could help in shedding light on this issue.…”

“…The morphology of the composites studied in this work, especially of PLANY1.5, was somewhat different from the one previously observed in the case of PCL/N6 composites, where larger-diameter fibers showed a poor interfacial adhesion, and bundles protruded from craters in the matrix. 47 Interestingly, in the composites studied in this work, all the fibers displayed the same optimal adhesion, irrespective of their diameter. On the contrary, in the case of PCL/N6 composites the finest filaments were firmly embedded in the matrix, their exposed end protruding directly from within the matrix, without the presence of craters at their base due to debonding, which was the case in the largest-diameter fibers.…”

Plastic Degradation and Its Environmental Implications with Special Reference to Poly(ethylene terephthalate)

“…Polymers have been produced based partially or entirely on starch [34,83,84,86], lactic acid [87,88], caprolactone [89], proteins [90], cellulose acetate [91] and other polysaccharides [92], and in many cases, the mechanical durability of these polymers has been improved through addition of plasticisers [90,92] or nanoparticles [89] or by carefully controlling production conditions [84]. One of the most significant groups of biopolymers is poly(hydroxyalkanoates) (PHAs).…”

Influence of clay organic modifier on morphology and performance of poly(ε-caprolactone)/clay nanocomposites

“…As stated by the supplier, the interlayer spacing of the (001) plane (d 001 ) for this type of organically modified clay is 3.15 nm; thus, the corresponding reflection in the WAXD pattern should appear at 3.10° 2θ, just within the measurable range of the instrument, as indicated with the arrow in Fig. 41 The experimental protocol for the preparation of nanocomposites applied in the pre-_________________________________________________________________________________________________________________________ Available on line at www.shd.org.rs/JSCS/ (CC) 2015 SCS. As in the case of the nanocomposites with the C30B clay, the absence of reflections in the WAXD patterns of the nanocomposites implies that the dispersion of the clay in the nanocomposites was either intercalated, with a d-spacing greater than 3.15 nm, or exfoliated.…”