Poly(lactic acid) plasticized by biodegradable glyceryl lactate

Lipase-Catalysed Polymerization of Eutectic Mixtures

Aiming to reduce the toxicity and operational costs often associated to chemical processes, the enzymatic synthesis is applied herein as a sustainable route for producing polyesters. The use of NADES' (Natural Deep Eutectic Solvents) components as a source of monomers for the synthesis of polymers through lipase-catalyzed esterification in an anhydrous medium is detailed for the first time. Three NADES composed by glycerol and an organic base, or acid, were used to produce polyesters, through polymerization reactions catalyzed by Aspergillus oryzae lipase. High polyester conversion rates (above 70 %), containing at least 20 monomeric units (glycerol:organic acid/base (1 : 1)), were observed by matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) analysis. The NADES monomers' capacity for polymerization, along with their non-toxicity, cheap cost, and simplicity of production, sets up these solvents as a greener and cleaner approach for the synthesis of high value-added products.

Tailoring Oligomeric Plasticizers for Polylactide through Structural Control

Structural variations (oligolactide segments, functionalized end groups, and different plasticizer cores) were utilized to tailor the performances of biobased plasticizers for polylactide (PLA). Six plasticizers were developed starting from 1,4-butanediol and isosorbide as cores: two monomeric (1,4-butanediol levulinate and isosorbide levulinate) and four oligomeric plasticizers with hydroxyl or levulinate ester end groups (1,4-butanediol-based oligolactide, isosorbide-based oligolactide, 1,4-butanediol-based oligomeric levulinate, and isosorbide-based oligomeric levulinate). Structural variations in plasticizer design were reflected in the thermal stability, plasticizing efficiency, and migration resistance. The monomeric plasticizer 1,4-butanediol levulinate decreased the glass-transition temperature of PLA from 59 to 16 °C and increased the strain at break substantially from 6 to 227% with 20 wt % addition. 1,4-Butanediol-based oligomeric levulinate exhibited better thermal stability and migration resistance, though the plasticizing efficiency was slightly lower (glass-transition temperature = 28 °C; strain at break = 202%). Compared to PLA films plasticized by plasticizers with flexible butanediol cores, those plasticized by plasticizers with rigid isosorbide cores exhibited higher Young's modulus and thermal stability and lower plasticizing efficiency. Furthermore, plasticizers with levulinate ester end groups had improved thermal stability, plasticizing efficiency, and migration resistance compared to the corresponding plasticizers with hydroxyl end groups. Hence, a set of controlled structural variations in plasticizer design were successfully demonstrated as a potent route to tailor the plasticizer performances.

Use of group 13 aryloxides for the synthesis of green chemicals and oxide materials

In this work, group 13 metal aryloxides [Al(MesalO)3] (1), [Me2Ga(MesalO)]2 (2), [AlLi3(MesalO)6] (3) and [Me2GaLi(MesalO)2(THF)] (4), were obtained by reaction of methyl salicylate (MesalOH) with group-13 alkyls MMe3 (for M...

A rapid and non-destructive method for detecting the water-holding capacity of pork using composite film

Water-holding capacity (WHC) is an important indicator of pork quality, but the existing detection methods of WHC are either expensive or time-consuming. In this study, a new method of pork WHC detection was developed by a composite film. The preparation method, mechanical properties and service life of the composite film were studied. The result showed that composite film was 0.46 ± 0.06 mm thick and had a service life of 21 days, tensile strength of 7.72 ± 0.11 MPa and the elongation at break of 28.54 ± 0.15%. Thirty groups of pork samples were randomly selected to build the model and another twenty groups were used to verify the model accuracy. Results showed that the accuracy of composite film coupled with Fisher discriminant model to detect the WHC of pork is 90%. This study demonstrates the high value of composite film as a detection tool to classify WHC of pork.