01. Soo bandhigida cellulose
Cellulose waa polysaccharide macromolecular ah oo ka kooban gulukoos. Kuma milmo biyaha iyo dareereyaasha guud ee dabiiciga ah. Waa qaybta ugu weyn ee derbiga unugyada dhirta, waana polysaccharide-ka ugu baahsan uguna badan dabiiciga.
Cellulose waa kheyraadka ugu badan ee la cusboonaysiin karo ee dhulka ku yaal, waana polymer dabiici ah oo leh ururinta ugu badan. Waxay leedahay faa'iidooyinka ah inay noqoto mid la cusboonaysiin karo, gebi ahaanba burburi karta, iyo iswaafajin wanaagsan oo bayooloji ah.
02. Sababaha wax looga beddelayo cellulose-ka
Unugyada macromolecules-ka ee Cellulose waxay ka kooban yihiin tiro badan oo kooxo -OH ah. Saamaynta isku-xidhka haydarojiin awgeed, xoogga u dhexeeya macromolecules-ka ayaa ah mid aad u weyn, kaas oo horseedi doona enthalpy dhalaal badan △H; dhanka kale, waxaa jira giraangiraha ku jira macromolecules-ka cellulose. Sida qaab-dhismeedka, adkaanta silsiladda molecular-ka ayaa ka weyn, taas oo horseedi doonta isbeddel yar oo entropy ah oo dhalaalaysa ΔS. Labadan sababood waxay ka dhigayaan heerkulka cellulose-ka dhalaalay (= △H / △S) inuu noqdo mid sarreeya, heerkulka kala-go'idda cellulose-kuna uu yahay mid hooseeya. Sidaa darteed, marka cellulose-ka lagu kululeeyo heerkul gaar ah, fiilooyinka ayaa soo bixi doona. Ifafaalaha ah in cellulose-ku uu burburay ka hor inta uusan bilaabin inuu dhalaalo, sidaas darteed, farsamaynta walxaha cellulose-ku ma qaadan karto habka marka hore dhalaalinta ka dibna qaabaynta.
03. Muhiimadda wax ka beddelka cellulose-ka
Iyada oo si tartiib tartiib ah loo dhimayo kheyraadka fosil-ka iyo dhibaatooyinka deegaanka ee sii kordhaya ee ay sababaan dharka kiimikada ee qashinka ah, horumarinta iyo isticmaalka agabka fiber-ka ee dabiiciga ah ee la cusboonaysiin karo ayaa noqotay mid ka mid ah meelaha ugu kulul ee dadku fiiro gaar ah u yeeshaan. Cellulose waa kheyraadka dabiiciga ah ee la cusboonaysiin karo ee ugu badan dabiiciga ah. Waxay leedahay sifooyin aad u fiican sida hygroscopicity wanaagsan, antistatic, permeability hawo xooggan, midabayn wanaagsan, xirasho raaxo leh, habayn fudud oo dharka ah, iyo bayooloji ahaan burbursan. Waxay leedahay astaamo aan la barbar dhigi karin fiilooyinka kiimikada.
Molecules-ka Cellulose waxay ka kooban yihiin tiro badan oo kooxo hydroxyl ah, kuwaas oo si fudud loo samayn karo isku xidhka hydrogen-ka gudaha iyo kan gudaha molecular-ka, waxayna ku burburaan heerkul sare iyagoon dhalaalin. Si kastaba ha ahaatee, cellulose waxay leedahay falcelin wanaagsan, isku xidhkeeda hydrogen-kana waxaa burburin kara wax ka beddelka kiimikada ama falgalka tallaalka, kaas oo si wax ku ool ah hoos ugu dhigi kara barta dhalaalka. Iyada oo ah noocyo kala duwan oo wax soo saar warshadeed, waxaa si weyn loogu isticmaalaa dharka, kala-soocidda xuubka, balaastikada, tubaakada iyo dahaarka.
04. Wax ka beddelka etherification-ka cellulose
Cellulose ether waa nooc ka mid ah noocyada cellulose ee laga helo wax ka beddelka etherification ee cellulose. Waxaa si weyn loo isticmaalaa sababtoo ah dhumucdiisa aadka u fiican, emulsification, suspension, sameynta filimka, colloid-ka ilaalinta, haynta qoyaanka, iyo sifooyinka dhejiska. Waxaa loo isticmaalaa cuntada, daawada, sameynta warqadda, rinjiga, qalabka dhismaha, iwm.
Kala-soocidda cellulose waa taxane ka kooban waxyaabo ay soo saaraan falgalka kooxaha hydroxyl ee silsiladda molecular-ka cellulose iyadoo la adeegsanayo wakiilada alkylating-ka xaaladaha alkaline-ka. Isticmaalka kooxaha hydroxyl wuxuu yareeyaa tirada isku-xidhka haydarojiinada intermolecular si loo yareeyo xoogagga intermolecular-ka, sidaas darteedna wuxuu hagaajiyaa xasilloonida kulaylka ee cellulose-ka, wuxuu hagaajiyaa waxqabadka habaynta walxaha, isla markaana wuxuu yareeyaa barta dhalaalka ee cellulose-ka.
Tusaalooyinka saamaynta wax ka beddelka etherification ee hawlaha kale ee cellulose:
Iyagoo adeegsanaya cudbi la safeeyey oo ah agabka ceeriin ee aasaasiga ah, cilmi-baarayaashu waxay isticmaaleen hab hal-tallaabo ah oo ether ah si ay u diyaariyaan ether-ka isku-dhafka ah ee carboxymethyl hydroxypropyl cellulose oo leh falcelin isku mid ah, dheellitirnaan sare, iska caabin aashito wanaagsan iyo iska caabin cusbo iyada oo loo marayo falgallada alkalization iyo etherification. Iyagoo adeegsanaya habka etherification-ka hal-tallaabo ah, cellulose-ka carboxymethyl hydroxypropyl ee la soo saaray wuxuu leeyahay iska caabin milix wanaagsan, iska caabin aashito iyo milmi. Iyadoo la beddelayo qaddarka qaraabada ah ee propylene oxide iyo chloroacetic acid, alaabada leh waxyaabo kala duwan oo carboxymethyl iyo hydroxypropyl ah ayaa la diyaarin karaa. Natiijooyinka tijaabada waxay muujinayaan in cellulose-ka carboxymethyl hydroxypropyl ee lagu soo saaro habka hal-tallaabo uu leeyahay wareeg wax soo saar oo gaaban, isticmaalka dareeraha oo hooseeya, badeecaduna waxay leedahay iska caabin aad u fiican oo ku wajahan milixda monovalent iyo kuwa kala duwan iyo iska caabin aashito wanaagsan.
05. Rajada wax ka beddelka etherification-ka cellulose
Cellulose waa walax muhiim ah oo kiimiko iyo kiimiko ah oo hodan ku ah kheyraadka, cagaar iyo deegaan ahaan u fiican, iyo dib loo cusboonaysiin karo. Waxyaabaha ka soo baxa wax ka beddelka etherification cellulose waxay leeyihiin waxqabad aad u wanaagsan, noocyo badan oo isticmaal ah iyo saameyn isticmaal oo aad u wanaagsan, waxayna daboolaan baahiyaha dhaqaalaha qaranka ilaa xad weyn. Iyo baahiyaha horumarinta bulshada, iyadoo la raacayo horumarka tignoolajiyada ee joogtada ah iyo hirgelinta ganacsiga mustaqbalka, haddii walxaha ceeriin ee synthetic-ga iyo hababka synthetic-ga ee cellulose-ka laga sameeyo ay warshado badan noqon karaan, si buuxda ayaa loo isticmaali doonaa oo loo hirgelin doonaa codsiyo ballaaran. Qiimaha
Waqtiga boostada: Febraayo-20-2023