Study On The Synthesis Of Biodegradable Polyester Used In Cosmetics Raw Materials

Aliphatic polyester, especially polycaprolactone and polylactide, is widely used as cosmetics raw materials in cosmetic products due to their biocompatibility and biodegradable. The polymer can be used as thickening agent, surfactants, cosmetic packaging materials and a kind of nano capsule material to be applied to cosmetic formula system. The human skin could absorb more active substance of cosmetic owe to the size of nanomaterials. Metal catalyst system as important key in ring-opening polymerization of cyclic ester. The metal catalytic activity lies in the design and the selection of ligands.In this paper, we choose metal zinc catalytic system which is low toxicity, inexpensive and obtain readily, designed and synthesized Salen-type zinc complexes. Study on the salen znic catalytic electronic and steric effects how to affect the catalytic performance of ε-caprolactone polymerization. The ε-caprolactone ring-opening mechanism of catalysts were discussed. The salen zinc complexes were characterized by 1HNMR and 13 CNMR, and the polycaprolactone(PCL) characterized by GPC.1. 3,5-di-tert-butyl-2-hydroxybenzaldehyde or 2-hydroxybenzaldehyde, alkyl or aromatic amines and zinc acetate as a raw material, which obtained 12 salen zinc complexes(C1-C12), and then study on their activity. The results showed that C1-C12 have different degree catalytic activity, steric hindrance moderate and electron-withdrawing substituent increase the catalytic activity. In contrast, the activity of backbone with 3,5-di-tert-butyl-2-hydroxybenzaldehyde are higher than the 2-hydroxybenzaldehyde. The catalytic activity become more better when-N with-iPr,-nBu,-Cy,-Bn in the structure of C1-C6. It will affect the coordination of the monomer to the metal zinc due to the structure’s-N with-tBu which has big steric hindrance. Therefore, the catalyst has low activity. C6 has electron withdrawing substituents, then the metal zinc can increase the electropositive, which is more conducive to the ring-opening polymerization of cyclic esters. With benzyl alcohol initiator, the catalytic activity is higher. Thus we ensure that the polymerization mechanism is monomer activation mechanism.2. Health chemical testing and biological safe evaluation of PCL. The results showed that the content of heavy metals, such as lead, arsenic and mercury, were lower than the cosmetic hygiene norms requirements. The experiments meet the heat requirements, and the heat sources of extracts comply with the limits. PCL was identified as a non-toxic of cosmetic raw materials.3.The PCL was used in cosmetic formulations.