Study On The Preparation And Mechanism Of Medical TPU And PP Antibacterial Materials

In this paper,four kinds of nanoscale antibacterial agents(AEM5700-A,RHA-S,RHA-M and RHA-T2)and four non nanoscale types(PC520S,PC18S,PC160S and PC100Z)were added into the two substrates of PP and TPU to prepare the antibacterial comp osite PP and TPU.The antibacterial properties of the composites were characterized by bacteriostasis ring and contact membrane method,and the mechanical properties of the composites were detected by the electronic universal testing machine and the impact tester,and the thermal properties of the composites were characterized by the thermal weight loss analyzer.The antibacterial mechanism was preliminarily explored by out of test and differential scanning calorimeter.(1)For TPU,adding four kinds of nanoscale antibacterial agents(AEM5700-A,RHA-S,RHA-M,RHA-T2),showed that in the culture medium of Staphylococcus aureus and Escherichia coli produced obvious bacteriostasis ring,the diameter of the bacteriostasis ring was greater than 7mm,indicating that the antibacterial properties of the TPU antibacterial materials all showed good antibacterial properties to the two species,the antibacterial properties were enhanced with the increase of the amount of antibacterial agents added,and the antibacterial properties of TPU composites with AEM5700-A and RHA-S antibacterial agents were better than those of RHA-M and RHA-T2;Adding four kinds of antibacterial agents(PC160S,PC100Z,PC520S,PC18S),TPU composites did not produce bacteriostasis ring to Staphylococcus aureus and Escherichia coli.In the membrane method test,the composite with PC100Z type antibacterial agent showed certain resistance to Escherichia coli,in which the content exceeded more than 0.4%.At the time,the antibacterial rate of the composite material can reach 100%.(2)For PP,adding four kinds of nanoscale antibacterial agents(AEM5700-A,RHA-S,RHA-M,RHA-T2),composite exhibited good antibacterial properties to Staphylococcus aureus or Escherichia coli,and the antibacterial properties of PP.antibacterial composites with AEM5700-A and RHA-S antibacterial agents were better than RHA-M and RHA-T2 type antibacterial agents.All the two kinds of bacteria selected by the test had antibacterial effect;Adding four non nanoscale antimicrobials(PC160S,PC100Z,PC520S,PC18S),PP composite had no bacteriostasis in the culture medium of two tested bacteria.When the content of the PC100Z type antibacterial agent was more than or equal to 0.4%,the anti bacteria rate of the composite can reach 100%.(3)The tensile strength and elongation at break of the TPU with four nanoscale antibacterial agents changed little.When the addition amount was 0.2%,the impact strength of the blends was increased by 8%.When the content was more than 0.2%,the impact strength decreased with the increase of content.After adding four kinds of non nanoscale antimicrobials,the tensile strength,elongation at break and impact of the blends were added.(4)After adding four nanoscale antibacterial agents to the PP substrate,the content of four kinds of antibacterial agents was 0.2%,the tensile strength of the PP composites increased by about 20%,and the elongation at break of the PP composites increased by about 10%;The impact strength of RHA-S composite was reduced by about 18%.Four kinds of non nanoscale antibacterial agents were added to the PP base material,and the strength of the material was lower than that of the pure PP material,but the toughness was improved,which showed that the elongation at break of the material was larger than that of the antiseptic.(5)According to the dissolution test of PP antibacterial material and TPU antibacterial material,it was believed that the effective antibacterial components in the material could be released into the environment under the drive of the difference of the ionic concentration between the surface and the inner of the material in the liquid environment,and the material showed goodantiseptic and antibacterial durability;In the dissolution experiment,thedissolution of silver ions had a close relationship with the crystallinity of the material.The higher the crystallinity of the material,the lower the dissolution and dissolution rate;The more amorphous areas of the material,which would be more favorable to dissolve,and the material would show more ideal antibacterial properties.