Mushonga wakasanganiswa wepoly-L-lactic acid uye ethyl cellulose mu chloroform uye yakasanganiswa mhinduro yePLLA uye methyl cellulose mu trifluoroacetic acid yakagadzirwa, uye PLLA / cellulose ether blend yakagadzirwa nekukanda;Misanganiswa yakawanikwa yairatidzwa nemashizha ekushandura infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) uye X-ray diffraction (XRD).Pane hydrogen bond pakati pePLLA ne cellulose ether, uye zvikamu zviviri izvi zvinopindirana.Nekuwedzera kwe cellulose ether content mumusanganiswa, iyo inonyunguduka, crystallinity uye crystal kutendeseka yemusanganiswa zvose zvichaderera.Kana iyo MC yemukati yakakwira kupfuura 30%, anenge amorphous musanganiswa anogona kuwanikwa.Naizvozvo, cellulose ether inogona kushandiswa kushandura poly-L-lactic asidhi kugadzirira degradable polymer zvinhu zvine hunhu hwakasiyana.
Keywords: poly-L-lactic acid, ethyl cellulose,methyl cellulose, kusanganisa, cellulose ether
Iko kuvandudza uye kushandiswa kwemapolymers echisikigo uye zvinoshatisa synthetic polymer zvinhu zvichabatsira kugadzirisa dambudziko rezvakatipoteredza uye dambudziko rezviwanikwa rakatarisana nevanhu.Mumakore achangopfuura, tsvakiridzo pamusoro peiyo synthesis yezvigadzirwa zvepolymer zvinogoneka zvichishandisa zviwanikwazve sepolymer mbishi zvinhu zvakakwezva kutarisisa kwakapararira.Polylactic asidhi ndeimwe yeakakosha anokanganisa aliphatic polyesters.Lactic acid inogona kugadzirwa nekuviriswa kwezvirimwa (sechibage, mbatatisi, sucrose, zvichingodaro), uye inogonawo kuomeswa nema microorganisms.Icho chinhu chinogona kuvandudzwa.Polylactic asidhi inogadzirwa kubva kulactic asidhi neyakananga polycondensation kana ring-kuvhura polymerization.Chigadzirwa chekupedzisira chekuparara kwayo ilactic acid, iyo isingasvibise nharaunda.PIA ine yakanakisa mechaniki zvivakwa, processability, biodegradability uye biocompatibility.Naizvozvo, PLA haina chete kuwanda kwekushandisa mumunda webiomedical engineering, asi zvakare ine hombe misika inogona kuitika muminda yekupfeka, mapurasitiki, uye machira.
Mutengo wepamusoro wepoly-L-lactic acid uye hurema hwayo hwekuita senge hydrophobicity uye brittleness inomisa huwandu hwayo hwekushandisa.Kuti kuderedze mari yaro uye kuvandudza kushanda kwePLLA, kugadzirira, kuwirirana, morphology, biodegradability, mechanical properties, hydrophilic / hydrophobic balance uye minda yekushandiswa kwepolylactic acid copolymers uye blends yakanyatsodzidza.Pakati pavo, PLLA inoumba musanganiswa unoenderana nepoly DL-lactic acid, polyethylene oxide, polyvinyl acetate, polyethylene glycol, nezvimwewo. mumasikirwo.Cellulose derivatives ndizvo zvekutanga zvechisikigo zvepolymer zvinhu zvakagadzirwa nevanhu, izvo zvakanyanya kukosha zviri cellulose ethers uye cellulose esters.M.Nagata et al.akadzidza PLLA / cellulose blend system uye akawana kuti zvikamu zviviri zvakanga zvisingaenderani, asi crystallization uye degradation properties yePLLA yakakanganiswa zvikuru nechikamu che cellulose.N.Ogata et al akadzidza mashandiro uye chimiro chePLLA uye cellulose acetate blend system.Iyo patent yekuJapan yakaongororawo biodegradability yePLLA uye nitrocellulose musanganiswa.Y.Teramoto et al akadzidza kugadzirira, kupisa uye mashandiro ePLLA uye cellulose diacetate graft copolymers.Kusvika pari zvino, kune zvidzidzo zvishomanana pamusoro pekubatanidza system ye polylactic acid uye cellulose ether.
Mumakore achangopfuura, boka redu rave richiita tsvakiridzo yeyakananga copolymerization uye kusanganisa gadziriso yepolylactic acid nemamwe mapolymer.Kuti tibatanidze zvinhu zvakanakisa zvepolylactic acid nemutengo wakaderera we cellulose uye zvigadzirwa zvayo kugadzirira zvizere biodegradable polymer zvinhu, tinosarudza cellulose (ether) sechikamu chakagadziridzwa chekubatanidza kuchinjika.Ethyl cellulose uye methyl cellulose maviri akakosha cellulose ethers.Ethyl cellulose is water-insoluble non-ionic cellulose alkyl ether, inogona kushandiswa semishonga yezvokurapa, mapurasitiki, adhesives uye textile finishing agents.Methyl cellulose inonyungudika mumvura, ine yakanakisa kunyorova, kubatana, kuchengetedza mvura uye firimu-kuumba zvivakwa, uye inoshandiswa zvakanyanya muminda yezvivakwa zvekuvaka, machira, zvizorwa, mishonga yemishonga uye mapepa.Pano, PLLA / EC uye PLLA / MC blends yakagadzirirwa nekugadzirisa nzira yekukanda, uye kuwirirana, zvinhu zvinopisa uye crystallization ye PLLA / cellulose ether blends yakakurukurwa.
1. Chikamu chekuedza
1.1 Raw zvinhu
Ethyl cellulose (AR, Tianjin Huazhen Special Chemical Reagent Factory);methyl cellulose (MC450), sodium dihydrogen phosphate, disodium hydrogen phosphate, ethyl acetate, stannous isooctanoate, chloroform (zviri pamusoro zvese zvigadzirwa zveShanghai Chemical Reagent Co., Ltd., uye kuchena igiredhi reAR);L-lactic acid (giredhi remishonga, PURAC kambani).
1.2 Kugadzirira kusanganiswa
1.2.1 Kugadzirira kwepolylactic acid
Poly-L-lactic acid yakagadzirwa nenzira yakananga polycondensation.Weresa L-lactic acid aqueous solution nechikamu chechikamu che90% uye woiwedzera kune furasiki ine mitsipa mitatu, dehydrate pa 150 ° C kwemaawa maviri pasi pekumanikidzwa kwakajairika, wozoita kwemaawa maviri pasi pekumanikidza kwe13300Pa, uye pakupedzisira. react kwemaawa mana pasi pevacuum ye3900Pa kuti uwane dehydrated prepolymer zvinhu.Huwandu hwese hwelactic acid aqueous solution kubvisa mvura inobuda ndiyo huwandu hweprepolymer.Wedzera stannous chloride (chikamu chezhinji 0.4%) uye p-toluenesulfonic acid (chiyero chestannous chloride uye p-toluenesulfonic acid ndeye 1/1 molar ratio) catalyst system mune yakawanikwa prepolymer, uye mukugadzirisa masifa eMolecular akaiswa muchubhu. kusveta mvura shoma, uye kubvongodzwa kwemichina kwakachengetwa.Iyo yose sisitimu yakabatwa pane vacuum ye1300 Pa uye tembiricha ye150 ° C. kwemaawa gumi nematanhatu kuwana polymer.Dissolve polymer yakawanikwa muchloroform kugadzirira mhinduro ye5%, sefa uye kunaya neanhydrous ether kwemaawa makumi maviri nemana, kusefa mvura, woiisa mu -0.1MPa vacuum oven pa60°C kwemaawa gumi kusvika makumi maviri kuti uwane Yakachena yakaoma. PLA polymer.Huremu hwemamolecular huremu hwePLLA yakawanikwa yakatemerwa kuve 45000-58000 Daltons nepamusoro-performance liquid chromatography (GPC).Mienzaniso yaichengetwa mune desiccator ine phosphorus pentoxide.
1.2.2 Kugadzirira kwepolylactic acid-ethyl cellulose blend (PLLA-EC)
Weresa huwandu hunodiwa hwepoly-L-lactic acid uye ethyl cellulose kugadzira 1% chloroform mhinduro zvichiteerana, uye wozogadzira PLLA-EC yakasanganiswa mhinduro.Reshiyo yePLLA-EC yakasanganiswa mhinduro ndeiyi: 100/0, 80/20, 60/40, 40/60, 20/80, 0/l00, nhamba yekutanga inomiririra chikamu chikuru chePLA, uye nhamba yekupedzisira inomiririra huwandu hweEC Fraction.Mishonga yakagadzirirwa yakamutswa nemagnetic stirrer kwemaawa 1-2, ndokuzodururwa mundiro yegirazi kuti chloroform iite evapote zvakasikwa kuti igadzire firimu.Mushure mokunge firimu yakaumbwa, yakaiswa muvheni yevhavha kuti iome pakupisa kwakadzika kwemaawa gumi kuti ibvise zvachose chloroform mufirimu..Iyo yakasanganiswa mhinduro haina ruvara uye yakajeka, uye iyo yakasanganiswa firimu haina ruvara uye yakajeka.Musanganiswa wacho wakaomeswa uye wakachengetwa mune desiccator kuti ushandiswe gare gare.
1.2.3 Kugadzirira kwepolylactic acid-methylcellulose musanganiswa (PLLA-MC)
Weresa huwandu hunodiwa hwepoly-L-lactic acid uye methyl cellulose kugadzira 1% trifluoroacetic acid mhinduro zvichiteerana.Iyo PLLA-MC musanganiswa firimu yakagadzirwa nenzira imwechete seyo PLLA-EC musanganiswa firimu.Musanganiswa wacho wakaomeswa uye wakachengetwa mune desiccator kuti ushandiswe gare gare.
1.3 Muedzo wekuita
MANMNA IR-550 infrared spectrometer (Nicolet.Corp) yakayera infrared spectrum yepolymer (KBr tablet).DSC2901 differential scanning calorimeter (TA kambani) yakashandiswa kuyera DSC curve yesampuli, chiyero chekupisa chaive 5 ° C / min, uye tembiricha yekuchinja kwegirazi, nzvimbo yekunyungudika uye crystallinity yepolymer zvakayerwa.Shandisa Rigaku.Iyo D-MAX/Rb diffractometer yakashandiswa kuyedza iyo X-ray diffraction pateni yepolymer kuti idzidze crystallization zvimiro zvesample.
2. Migumisiro uye nhaurirano
2.1 Infrared spectroscopy research
Fourier shandura infrared spectroscopy (FT-IR) inogona kudzidza kupindirana pakati pezvikamu zvemusanganiswa kubva pamaonero echikamu chemolecular.Kana mahomopolymers maviri achienderana, kuchinja kwehuwandu, kuchinja muhukuru, uye kunyange kuonekwa kana kunyangarika kwepamusoro pemaitiro ezvikamu zvinogona kuonekwa.Kana maviri homopolymers asingaenderane, spectrum yemusanganiswa ingori superposition yemahomopolymers maviri.Muchikamu chePLLA, pane kutambanudza kwepamusoro kweC = 0 pa 1755cm-1, peak isina simba pa 2880cm-1 inokonzerwa neC-H inotambanudza kutinhira kweboka re methine, uye bhendi rakafara pa 3500 cm-1 inokonzerwa nematerminal hydroxyl groups.MuEC spectrum, hunhu hwepamusoro pa 3483 cm-1 ndiyo OH inotambanudza vibration peak, zvichiratidza kuti kune O-H mapoka asara pane molecular cheni, nepo 2876-2978 cm-1 ndiyo C2H5 inotambanudza vibration peak, uye 1637. cm-1 ndeye HOH Kupeta kudengenyeka kwepamusoro (kunokonzerwa nemuenzaniso unonwisa mvura).Kana PLLA yakasanganiswa neEC, muIR spectrum yehydroxyl nharaunda yePLLA-EC musanganiswa, iyo O-H peak inoshanduka kune yakaderera wavenumber nekuwedzera kweEC zvemukati, uye inosvika padiki kana PLLA/Ec iri 40/60 wavenumber, uye yozochinjirwa kunhamba dzepamusoro, zvichiratidza kuti kudyidzana pakati pePUA ne0-H yeEC kwakaoma.Munharaunda yeC = O vibration ye 1758cm-1, iyo C = 0 peak yePLLA-EC yakashandura zvishoma kune nhamba yakaderera yemafungu nekuwedzera kweEC, iyo yakaratidza kuti kuwirirana pakati peC = O neOH yeEC kwakanga kusina simba.
Mune iyo spectrogram ye methylcellulose, iyo hunhu hwepamusoro pa 3480cm-1 ndiyo O-H inotambanudza vibration peak, ndiko kuti, kune asara O-H mapoka paMC molecular chain, uye HOH beng vibration peak iri pa1637cm-1, uye iyo MC reshiyo EC yakanyanya hygroscopic.Zvakafanana nePLLA-EC blend system, mu infrared spectra yehydroxyl region yePLLA-EC blend, O-H peak inoshanduka nekuwedzera kwe MC content, uye ine hushoma wave nhamba kana PLLA/MC iri. 70/30.Munharaunda yeC=O vibration (1758 cm-1), iyo C=O peak inochinja zvishoma kuenda kuzasi kwemasaisayi nekuwedzera kweMC.Sezvatakambotaura, kune mapoka mazhinji muPLA anogona kuumba kudyidzana kwakakosha nemamwe mapolymer, uye mhedzisiro yeiyo infrared spectrum inogona kunge iri iyo yakasanganiswa mhedzisiro yekuwanda kwakakosha kupindirana.Mumusanganiswa system yePLLA uye cellulose ether, panogona kunge paine akasiyana hydrogen bond mafomu pakati peester boka rePLLA, iyo terminal hydroxyl boka uye ether boka re cellulose ether (EC kana MG), uye yakasara mapoka ehydroxyl.PLLA neEC kana MCs inogona kuenderana.Zvinogona kunge zvichikonzerwa nekuvapo uye kusimba kwezvisungo zvehydrogen zvakawanda, saka shanduko munharaunda yeO-H inonyanya kukosha.Zvisinei, nekuda kwekudzivisa steric yeboka re cellulose, hydrogen bond pakati peC = O boka rePLA uye O-H boka re cellulose ether haina simba.
2.2 DSC tsvagiridzo
DSC curves yePLLA, EC uye PLLA-EC inosanganiswa.Girazi yekushandura tembiricha Tg yePLA ndeye 56.2 ° C, tembiricha yekunyungudika kwekristaro Tm i174.3 ° C, uye crystallinity i55.7%.EC iamorphous polymer ine Tg ye43°C uye haina tembiricha yekunyungudika.Iyo Tg yezvikamu zviviri zvePLLA neEC zviri pedyo zvakanyanya, uye matunhu maviri ekuchinja anopindirana uye haagone kusiyaniswa, saka zvakaoma kuishandisa semucherechedzo wekuenderana kwehurongwa.Nekuwedzera kweEC, Tm yePLLA-EC yakasanganiswa yakaderera zvishoma, uye crystallinity yakaderera (iyo crystallinity yemuenzaniso ne PLLA / EC 20 / 80 yaiva 21.3%).Iyo Tm yemusanganiswa yakadzikira nekuwedzera kweMC zvemukati.Kana PLLA / MC yakaderera pane 70/30, iyo Tm yemusanganiswa yakaoma kuyera, ndiko kuti, inenge amorphous blend inogona kuwanikwa.Kudzikira kwekunyungudika kwemusanganiswa wekristaro mapolymers ane amorphous polymers kunowanzo kukonzerwa nezvikonzero zviviri, imwe ndeye dilution mhedzisiro yeamorphous component;imwe yacho inogona kunge iri mhedzisiro yemaitiro senge kuderedzwa kwekristalllization kukwana kana saizi yekristaro yecrystalline polymer.Mhedzisiro yeDSC yakaratidza kuti mumisanganiswa system yePLLA uye cellulose ether, zvikamu zviviri izvi zvakabatana zvishoma, uye crystallization process yePLLA mumusanganiswa yakadziviswa, zvichikonzera kuderera kweTm, crystallinity uye crystal size yePLA.Izvi zvinoratidza kuti kuwirirana kwezvikamu zviviri zvePLLA-MC system inogona kunge iri nani pane yePLLA-EC system.
2.3 X-ray diffraction
Iyo XRD curve yePLA ine peak yakasimba pa2θ ye16.64 °, iyo inoenderana ne020 crystal plane, nepo nhongonya dziri pa2θ dze14.90 °, 19.21 ° uye 22.45 ° dzinoenderana ne101, 023, uye 121 zvakateerana.Pamusoro, ndiko kuti, PLLA ndeye α-crystalline chimiro.Nekudaro, hapana chekristaro chimiro chepamusoro mune diffraction curve yeEC, iyo inoratidza kuti iyo amorphous chimiro.Apo PLLA yakasanganiswa neEC, iyo yepamusoro pa16.64 ° yakawedzera zvishoma nezvishoma, kusimba kwayo kwakaderera, uye yakafamba zvishoma kune imwe kona yakaderera.Kana iyo EC yemukati yaive 60%, iyo crystallization peak yakanga yapararira.Narrow x-ray diffraction peaks inoratidza yakakwirira crystallinity uye hombe tsanga saizi.Iyo yakakura iyo diffraction peak, idiki saizi yezviyo.Kuchinja kwekusiyana kwepamusoro kusvika kune yakaderera kona kunoratidza kuti kupatsanurwa kwezviyo kunowedzera, ndiko kuti, kuvimbika kwekristini kunoderera.Pane chisungo chehydrogen pakati pePLLA neEc, uye saizi yezviyo uye crystallinity yePLA inoderera, izvo zvingave zvichikonzerwa nekuti EC inowirirana nePLLA kuumba chimiro cheamorphous, nekudaro ichideredza kutendeseka kwekristaro chimiro chemusanganiswa.Iwo X-ray diffraction mhedzisiro yePLLA-MC inoratidzawo mhedzisiro yakafanana.Iyo X-ray diffraction curve inoratidza mhedzisiro yereshiyo yePLLA / cellulose ether pane chimiro chemusanganiswa, uye mhedzisiro inoenderana zvachose nemhedzisiro yeFT-IR uye DSC.
3. Mhedziso
Iyo yakasanganiswa system yepoly-L-lactic acid uye cellulose ether (ethyl cellulose uye methyl cellulose) yakadzidzwa pano.Kugarisana kwezvikamu zviviri zvemusanganiswa system yakadzidzwa nenzira yeFT-IR, XRD uye DSC.Mhedzisiro yacho yakaratidza kuti hydrogen bonding yaivepo pakati pePLLA ne cellulose ether, uye zvikamu zviviri muhurongwa zvaienderana.Kuderera kwePLLA / cellulose ether ratio kunokonzera kuderera kwekunyunguduka, crystallinity, uye crystal integrity yePLLA mumusanganiswa, zvichiita kuti kugadzirirwa kwezvibatanidza zvakasiyana-siyana zvekristallinity.Nokudaro, cellulose ether inogona kushandiswa kugadzirisa poly-L-lactic acid, iyo ichabatanidza kushanda kwakanakisisa kwepolylactic acid uye kudhura kwakaderera kwe cellulose ether, iyo inobatsira pakugadzirira zvakakwana biodegradable polymer zvinhu.
Nguva yekutumira: Jan-13-2023