Ukuguqulwa kwe-cellulose etherification

01. Ukwaziswa kwe-cellulose

I-Cellulose yi-polysaccharide enkulu eyenziwe yi-glucose. Ayinyibiliki emanzini nakwizinto eziphilayo ngokubanzi. Yinto ephambili eludongeni lweseli yesityalo, kwaye ikwayeyona polysaccharide isasazeke kakhulu kwaye ininzi kakhulu kwindalo.

I-Cellulose yeyona nto ifumaneka lula emhlabeni, kwaye ikwayi-polymer yendalo eqokelela kakhulu. Inezibonelelo zokuba iyakwazi ukuhlaziywa, ibola ngokupheleleyo, kwaye ihambelana kakuhle ne-biocompatibility.

02. Izizathu zokutshintsha i-cellulose

Iimacromolecule zeseli ziqulathe inani elikhulu lamaqela e-OH. Ngenxa yempembelelo yeebhondi zehydrogen, amandla phakathi kweemacromolecule makhulu, nto leyo eya kukhokelela kwi-enthalpy enkulu yokunyibilika △H; kwelinye icala, kukho izangqa kwiimacromolecule zeseli. Njengesakhiwo, ukuqina kwetsheyini yeemolekyuli kukhulu, nto leyo eya kukhokelela kutshintsho oluncinci lwe-entropy yokunyibilika ΔS. Ezi zizathu zimbini zenza ukuba ubushushu be-cellulose enyibilikisiweyo (= △H / △S ) bube phezulu, kwaye ubushushu bokubola kweselilulose bube phantsi. Ke ngoko, xa i-cellulose ifudunyezwa kubushushu obuthile, iifayibha ziya kuvela. Imeko yokuba i-cellulose ibolile ngaphambi kokuba iqale ukunyibilika, ke ngoko, ukucutshungulwa kwezinto zeselilulose akunakusebenzisa indlela yokunyibilika kokuqala uze emva koko ubumbe.

03. Ukubaluleka kokuguqulwa kweselilulose

Ngenxa yokuphela kancinci kwezixhobo zefosili kunye neengxaki ezinzulu zokusingqongileyo ezibangelwa yimpahla yefayibha yeekhemikhali elahliweyo, uphuhliso kunye nokusetyenziswa kwezinto zefayibha ezivuselelekayo zendalo kuye kwaba yenye yezona ndawo zibalulekileyo abantu abaziqwalaselayo. I-Cellulose yeyona nto ixhaphakileyo yendalo evuselelekayo. Ineempawu ezintle ezifana ne-hygroscopicity elungileyo, i-antistatic, i-air permeability enamandla, i-dyeability elungileyo, ukunxiba kakuhle, ukucutshungulwa lula kwelaphu, kunye ne-biobolidability. Ineempawu ezingenakuthelekiswa neefayibha zeekhemikhali.

Iimolekyuli zeseli ziqulathe inani elikhulu lamaqela e-hydroxyl, okulula ukwenza iibhondi ze-hydrogen zangaphakathi kweemolekyuli kunye nezangaphakathi kweemolekyuli, kwaye zibola kumaqondo obushushu aphezulu ngaphandle kokunyibilika. Nangona kunjalo, i-cellulose ine-reactivity entle, kwaye ibhondi yayo ye-hydrogen inokutshatyalaliswa ngokuguqulwa kweekhemikhali okanye i-grafting reaction, enokuthi yehlise ngempumelelo i-melting point. Njengeemveliso ezahlukeneyo zoshishino, isetyenziswa kakhulu kwimpahla yokulahlwa, ukwahlula i-membrane, iiplastiki, icuba kunye neengubo.

04. Ukuguqulwa kwe-cellulose etherification

I-Cellulose ether luhlobo lwe-cellulose derivative efunyenwe ngokuguqulwa kwe-etherification ye-cellulose. Isetyenziswa kakhulu ngenxa yokuqina kwayo okuhle, i-emulsification, i-suspension, ukwakheka kwefilimu, i-colloid ekhuselayo, ukugcinwa komswakama, kunye neempawu zokunamathela. Isetyenziswa ekutyeni, kumayeza, ekwenzeni amaphepha, ekupeyinteni, kwizixhobo zokwakha, njl.njl.

Ukufakelwa kwe-cellulose kuluhlu lwee-derivatives eziveliswa yimpendulo yamaqela e-hydroxyl kwi-cellulose molecular chain kunye nee-alkylating agents phantsi kweemeko ze-alkaline. Ukusetyenziswa kwamaqela e-hydroxyl kunciphisa inani lee-intermolecular hydrogen bonds ukunciphisa amandla e-intermolecular, ngaloo ndlela kuphucula uzinzo lobushushu be-cellulose, ukuphucula ukusebenza kwezixhobo, kwaye kwangaxeshanye kunciphisa i-melting point ye-cellulose.

Imizekelo yeziphumo zokuguqulwa kwe-etherification kweminye imisebenzi ye-cellulose:

Besebenzisa umqhaphu ocoliweyo njengezinto ezisisiseko, abaphandi basebenzise inkqubo ye-etherification yenyathelo elinye ukulungiselela i-ether ye-carboxymethyl hydroxypropyl cellulose complex ene-reaction efanayo, i-viscosity ephezulu, ukumelana ne-asidi elungileyo kunye nokumelana netyuwa ngokusebenzisa i-alkalization kunye ne-etherification reactions. Besebenzisa inkqubo ye-etherification yenyathelo elinye, i-carboxymethyl hydroxypropyl cellulose evelisiweyo inokumelana netyuwa okuhle, ukumelana ne-asidi kunye nokunyibilika. Ngokutshintsha ubungakanani be-propylene oxide kunye ne-chloroacetic acid, iimveliso ezinomxholo we-carboxymethyl kunye ne-hydroxypropyl ezahlukeneyo zinokulungiswa. Iziphumo zovavanyo zibonisa ukuba i-carboxymethyl hydroxypropyl cellulose eveliswe ngendlela yenyathelo elinye inomjikelo omfutshane wemveliso, ukusetyenziswa kwe-solvent ephantsi, kwaye imveliso inokumelana okuhle kakhulu ne-monovalent kunye ne-divalent salts kunye nokumelana okuhle ne-asidi.

05. Ithemba lokuguqulwa kwe-cellulose etherification

I-Cellulose zizinto ezibalulekileyo zekhemikhali kunye neekhemikhali ezityebileyo kwizixhobo, eziluhlaza kwaye zinobuhlobo nokusingqongileyo, kwaye ziyavuseleleka. Izinto eziphuma kwi-cellulose etherification modification zisebenza kakuhle kakhulu, uluhlu olubanzi lokusetyenziswa kunye nemiphumo emihle yokusetyenziswa, kwaye ziyahlangabezana neemfuno zoqoqosho lwesizwe ngokubanzi. Kwaye iimfuno zophuhliso loluntu, kunye nenkqubela phambili yetekhnoloji eqhubekayo kunye nokufezekiswa korhwebo kwixesha elizayo, ukuba izinto eziluhlaza zokwenziwa kunye neendlela zokwenziwa ze-cellulose derivatives zinokuphuhliswa ngakumbi kwimizi-mveliso, ziya kusetyenziswa ngokupheleleyo kwaye zifezekise uluhlu olubanzi lwezicelo. Ixabiso