INFLUENCE OF CARDANOL ENCAPSULATED ON THE PROPERTIES OF POLY(LACTIC ACID) MICROPARTICLES

In this study, microparticles of poly(lactic acid) (PLA) were produced to encapsulate cardanol, varying molar mass of the polymer matrix, concentration of the emulsifier (PVA) and concentration of the chemical additive (cardanol). The droplet size distribution, polydispersity index, morphology, the interaction between cardanol and PLA, cardanol encapsulation efficiency and release profile of this chemical additive were assessed. The morphological characterization showed that the microparticles containing cardanol were presented as microcapsules up to a maximum cardanol concentration limit that could be incorporated. The addition of cardanol during the production of the microparticles led to an increase in the average diameter of the microparticles obtained, both those with low and high molar mass (MPLA3 and MPLA100, respectively), with the increase depending on the quantity of cardanol incorporated. DSC results showed a shift in melting point and a change in Tg and Tm with the incorporation of cardanol, suggesting an interaction between cardanol and PLA matrix. Higher encapsulation efficiency and slower release of cardanol were achieved when using microparticles with higher molar mass (MPLA100). The microparticles of MPLA100/1PVA/50C provided the slowest additive release among the formulations tested. Therefore, the processes for encapsulation and controlled release of cardanol in the PLA matrix were efficient.本研究制备了聚乳酸（PLA）微颗粒以包封腰果酚，考察了聚合物基质摩尔质量、乳化剂（PVA）浓度以及化学添加剂（腰果酚）浓度对体系的影响。本研究对该体系的粒径分布、多分散性指数、形貌、腰果酚与PLA基质间的相互作用、腰果酚包封率以及该添加剂的释放曲线进行了表征与评估。形貌表征结果显示，在可掺入的最大腰果酚浓度阈值内，含腰果酚的微颗粒均以微胶囊形式存在。在微颗粒制备过程中添加腰果酚，会使所得微颗粒的平均粒径增大；无论针对低摩尔质量（MPLA3）还是高摩尔质量（MPLA100）的PLA微颗粒，该现象均成立，且粒径增幅随腰果酚掺入量的增加而提升。差示扫描量热法（DSC）结果表明，掺入腰果酚后，体系出现熔点偏移，且玻璃化转变温度（Tg）与熔融温度（Tm）发生变化，证实腰果酚与PLA基质之间存在相互作用。使用高摩尔质量的PLA微颗粒（MPLA100）时，可获得更高的腰果酚包封率以及更缓慢的释放效果。在所测试的所有配方中，MPLA100/1PVA/50C体系的添加剂释放速度最慢。综上，在PLA基质中包封腰果酚并实现其控释的工艺具备良好的有效性。