Salač Jan, Šerá Jana, Jurča Martin, Verney Vincent, Marek Adam A, Koutný Marek
Department of Environmental Protection Engineering, Faculty of Technology, Tomas Bata University, Vavrečkova 275, 760 01 Zlín, Czech Republic.
Institut de Chimie de Clermont-Ferrand, Université Clermont Auvergne, CNRS, F-63000 Clermont⁻Ferrand, France.
Materials (Basel). 2019 Feb 4;12(3):481. doi: 10.3390/ma12030481.
Orotic acid is a natural heterocyclic compound that acts as a nucleation agent in poly(lactic acid) (PLA). PLA materials with increasing orotic acid content were prepared and characterized. It was found that crystallinity of about 28% was reached with 0.3% content of the agent. Further enhancement in the content of the agent did not provoke any additional significant increase of crystallinity. Subsequently, it was investigated whether the orotic acid content affected photodegradation of PLA and, in the next phase, its biodegradation. The results of rheological measurements showed that the compound slightly accelerates photodegradation of the material, which was accompanied by the cleavage of PLA chains. Previous photodegradation was shown to accelerate the subsequent biodegradation by shortening the lag phase of the process, where the explanation is probably in the reduction of the polymer molecular weight during the photodegradation. Moreover, the presence of orotic acid in both initial and photodegraded samples was found to influence biodegradation positively by shortening the lag phase and increasing the observed maximal rate of the biodegradation.
乳清酸是一种天然杂环化合物，在聚乳酸（PLA）中作为成核剂。制备并表征了乳清酸含量不断增加的PLA材料。结果发现，当该成核剂含量为0.3%时，结晶度达到约28%。进一步增加该成核剂的含量并不会使结晶度有任何额外的显著提高。随后，研究了乳清酸含量是否会影响PLA的光降解，以及在下一阶段，是否会影响其生物降解。流变学测量结果表明，该化合物会略微加速材料的光降解，同时伴随着PLA链的断裂。先前的研究表明，光降解通过缩短该过程的滞后期来加速随后的生物降解，其原因可能是光降解过程中聚合物分子量的降低。此外，发现在初始样品和光降解样品中乳清酸的存在均通过缩短滞后期和提高观察到的生物降解最大速率对生物降解产生积极影响。
