Plasticized poly(lactic acid) reinforced with antioxidant covalent organic frameworks (COFs) as novel nanofillers designed for non-migrating active packaging applications

Hybrid Biocomposites Based on Poly(Lactic Acid) and Silica Aerogel for Food Packaging Applications

“…Thus, morphological characteristics of the cross cryo-fracture sections of film samples were evaluated by SEM and the images are shown in Figure 1. As expected, PLA presented a smooth and uniform surface where a rigid fracture typical of amorphous polymer [9] could be observed (Figure 1b), while plasticized samples presented plastic deformation, showing more ductile fracture patterns [12] (Figure 1c-h), in accordance with previous works [12,21,41]. In the case of silica aerogel based composites, the fracture surface resulted in more roughness (Figure 1d-h) as SiA concentration increased in the formulation.…”

“…This peak has been related with restrictions in the polymer chains due to the transition of the disorder to order PLA crystallites [42]-thus suggesting that a great part of the polymeric system was in an amorphous state as a consequence of the fast DSC cooling rate applied after the compression molding process [7]. As expected, ATBC reduced the melting temperature of PLA confirming again the good interaction between the ATBC plasticizer and the polymeric matrix, in accordance with previous works [7,21,41]. The melting temperatures of the composites resulted in being almost invariant with respect to the PLA-ATBC film.…”

“…As expected, the addition of ATBC had a clear effect on the plasticization of the PLA polymeric matrix, since it induced a decrease in the T g in all plasticized films. This reduction in the T g has been ascribed to the ability of citrate plasticizers to increase the mobility of the PLA polymer chains, caused by an increase in the free volume between them [14,21,41]. Although, from the obtained DSC curves in blend formulations, the two parallel baselines, before and after the T g , are not well defined, it is evident that the typical T g of PLA could not be seen at 58 • C, suggesting that, in PLA, reinforced films further decreased the T g , with respect to the PLA-ATBC sample.…”

Nanoscale covalent organic frameworks as theranostic platforms for oncotherapy: synthesis, functionalization, and applications

“…151 Some examples for the preparation of NCOFs by ultrasonic exfoliation are shown in Table 2. [150][151][152][153][154][155][156][157][158][159][160][161][162][163][164][165] Evidently, the weaker the interactions between the COF layers, the easier it becomes to perform ultrasonic exfoliation. TPA-COF constructed with tris(4-aminophenyl)amine and tris(4-formylphenyl)amine exible monomers with the C 3v symmetry conrmed this prediction.…”

“…Covalent post-SM based on a click reaction to form a triazole ring is an extremely versatile and efficient method that enables the development of custom-built COFs with tunable porosities and functionalities while maintaining their high crystallinity. 164,[290][291][292][293][294][295][296][297][298] The click reaction of vinyl with thiol is another typical clickchemistry-based post-SM method. For instance, vinylfunctionalized COF-V and 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecauorodecane-1-thiol with low surface free energy reacted in the presence of azobisisobutyronitrile (AIBN) as the catalyst to yield peruoroalkane-modied COF-VF ( Fig.…”