Study On Chemical Components Of Artemisia Argyllem Oil From Jiaodong Peninsula, Preparation And Antimicrobial Activities In Polyurethane Of Microcapusule

With the growth of environmental awareness, many countries mademore strict security requirements. In this new situation, study onefficiently, broard-spectrum and harmlessly environment-friendlyantibacterial and antifungal agent will be benefit for leather industry inlong-term healthy, sustainable development. Artemisia Argyi is a memberof the wild herbal composite wormwood family, and Artemisia Argyllemoil has good antibacterial capabilities. However, the oil for its volatilityhas a short life, affected its application. Hence, in order to improve thesustained release effect, volatile oil encapsulated with some kinds ofmicroporous wall membrane was considered by many researchers.Encapsulation may be defined as a process to entrap one substancewithin another substance. For typical industrial applications it can varyfrom several microns to several millimeters in diameter although there isan increasing interest in preparing nano-encapsulates. Encapsulates mightalso be defined by their particle size, e.g., nanoparticles, microcapsules,micro reservoir, etc. Encapsulates are basically particles with a core-shellstructure, but some of them can have a more complex structure, e.g. in aform of multiple cores embedded in a matrix. The substance that isencapsulated may be called as core material, the active agent, fill, internalphase, or payload phase. The substance encapsulating other material maybe called as coating, membrane, shell, carrier material, wall material,external phase, or matrix. The purpose of encapsulation is to stabilize active ingredient, control its release rate and/or convert a liquidformulation into a solid which is easier to handle.The microencapsulation by complex coacervation is widely knowndue to its simplicity, low costs of excipients and preparation procedurewhich still nowadays appears to be attractive for studies in this field. Onthe basis of previous work, the oil of Artemisia argyi grown in Jiaodongpeninsula was extracted by hydro-distillation, soxhlet extraction andsupercritical CO₂. The antimicrobial activity of the artemisia argyllem oilwas evaluated using agar diffusion and broth microdilution method invitro against Escherichia coli, Staphyloccocus aureus and aspergillusflavus. Gelatin and gum was used as the wall materials to preparemicrocapsule by a complex coacervation method. The technologicalconditions of microcapsulation, such as wall material concentration,core/wall ratio, gelatin/gum ratio, coacervation pH, stirring speed,gelatin/glutaraldehyde ratio, pH of crosslink and so on, were researchedand determined. In the basis of above work and study, artemisia argyllemoil microcapsule was applied in polyurethane, and tensile strength, theelongation at break of the PU films, softness change, the antimicrobialactivity and residual inhibition rate were investigated.The results of the study indicated that:1) The essential oil of Artemisia argyi grown in Jiaodong peninsula wasextracted by hydro-distillation, soxhlet extraction and supercritical CO₂.The chemical components of artemisia argyllem oil were studied and31active ingredients were identified, including monoterpenoids,sesquiterpenes and derivative. The varieties and contents of oil extractedby supercritical CO₂are higher than that of others and extraction rate is0.53%. The antimicrobial effect was studied in vitro against Escherichiacoli, Staphyloccocus aureus and aspergillus flavus. The results showedthat the oils had great potential antimicrobial activity against all3microorganisms especially to Escherichia coli and the minimuminhibitory concentration was0.1%（V/V）.2)The result showed that core/wall ratio=1, wall materialconcentration=2%, m（gelatin）:m（gum-arabic）=1:1, stirring speed=300r/min, m（gelatin）:m（glutaraldehyde）=1:1, coacervationpH=3.8, and crosslink pH=6were the best choice. The yield was89%and loading ofmicrocapsules was71%. The effects of the core/wall ratio, stirring speedand coacervation pH on the properties and morphologies of themicrocapsules were important. GC-MS indicated that entraping artemisiaargyllem oil did not destroy active ingredients. FT-IR spectrum provedthat the coacervate was formed by the physical interaction betweengelatin and gum Arabic. When the coacervation pH was3.8and crosslinkpH was6, the microcapsules possessed spherical morphology anduniform surface. The microcapsules had great potential antimicrobialactivity against escherichia coli, staphyloccocus aureus and aspergillusflavus. Inhibition rate on escherichia coli is99%. Compared withartemisia argyllem oil, microcapsules had better residual effect. At45℃and70%humidity for40days, the microcapsules had good antimicrobialactivity.3) Artemisia argyllem oil was applied in polyurethane, when thew（microcapsule） was more than2%, the PU membrane became soft.Tensile strength of PU membrane after adding microcapsule were more orless reduced. The PU films after being added microcapsule had greatantimicrobial activity against escherichia coli, staphyloccocus aureus andaspergillus flavus. When the w（microcapsule） was1.5%, the PU filmsstill had good antimicrobial activity after40days at45℃and70%humidity.