The paper describes a new method of copolymerization of glycolide with l-lactide with the
use of a low toxic compoundZr(acac)4as initiator at a temperature of 100 up to 150 °C. Copolymerization
at 150 °C is very fast and reached nearly 100% yield. The values of the copolymerization coefficients
were estimated as r
G = 3.3 and r
L = 0.5. The process of chain propagation was also examined, and a
significant influence of transesterification on the final structure of copolymer was observed. The
microstructure of the chain was determined by NMR spectroscopy. It was found that more segmental
structure had been formed as compared with the structure of the copolymer obtained in copolymerization
initiated by tin compounds. This structure influences thermomechanical properties of the copolymers.
The crystallinity of copolymers obtained is higher than that of the formed in the presence of Sn(oct)2.
One of their most characteristic features concerned their good mechanical properties, in many cases better
than those of adequate copolymers obtained with the use of tin compounds as initiators.
The use of biobased plastics is of great importance for many applications. Blending thermoplastic polylactide (PLA) with polyhydroxyalkanoate (PHA) enables the formulation of a more mechanically powerful material and this enables tailored biodegradation properties. In this study we demonstrate the 3D printing of a PLA/PHA blend as a potential candidate for biocompatible material applications. The filament for 3D printing consisted of PHA, which contains predominantly 3-hydroxybutyrate units and a small amount of 3
The anionic polymerization of L-lactide in the presence of the sodium poly(ethy1ene g1ycol)ate in tetrahydrofuran at 25 "C yields "tailored" ABA triblock copolymers having the expected compositions and molecular weights. During the polymerization, a slight racemization of L-lactide was observed. The water absorption experiments indicate that the introduction of the poly(ethy1ene glycol) block into the L-lactide polymer chain markedly increases its hydrophilicity. It was revealed that the morphology and mechanical properties of block copolymers depend strongly on their composition and thermal treatment.
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