Focus on Cellulose ethers

Izinto ezichaphazela indawo yokunyibilika kwe-hydroxyethyl cellulose

I-Hydroxyethyl cellulose (HEC) yi-ether ebalulekileyo ye-cellulose e-soluble yamanzi, esetyenziswa ngokubanzi kwiingubo, ukugaya ioli, amayeza kunye nezinye iindawo. Inqanaba layo lokunyibilika liyipharamitha ebalulekileyo yomzimba echaphazela ukucubungula kunye nokusetyenziswa kwayo. Izinto ezichaphazela indawo yokunyibilika kwe-hydroxyethyl cellulose inokwahlulwa ibe yimiba emininzi, efana nesakhiwo semolekyuli, iqondo lokutshintsha, ubunzima bemolekyuli, ikristale, ukungcola, kunye neemeko zokusingqongileyo.

1. Ubume bemolekyuli

I-Hydroxyethyl cellulose yimveliso ye-cellulose emva kwe-ethoxylation. Ubume bayo obusisiseko kukuba ii-athomu ze-hydrogen kwi-molecule ye-cellulose zithathelwa indawo ngamaqela e-hydroxyethyl. Indawo, inani kunye nomyalelo wokutshintshwa kwe-hydroxyethyl kuya kuchaphazela indawo yayo yokunyibilika.
Indawo yokutshintsha: Iyunithi nganye ye-glucose kwi-cellulose inamaqela amathathu e-hydroxyl anokutshintshwa. Ukutshintshwa kwiindawo ezahlukeneyo kuya kutshintsha isakhiwo sesithuba se-molecule, ngaloo ndlela kuchaphazela indawo yokunyibilika.
Inani lokutshintshwa: Ukunyuka kwenani labatshintshi ngokubanzi kunciphisa i-hydrogen bonding phakathi kweeamolekyu, ngaloo ndlela kunciphisa indawo yokunyibilika.
Ulungelelwaniso lolungiselelo olubambeleyo: Amalungu asasazwa ngokungakhethiyo kunye namalungu asasazwa rhoqo aneempembelelo ezahlukeneyo ekuguquguqukeni nasekunxibelelaneni kwetsheyina lemolekyuli, ngaloo ndlela echaphazela indawo yokunyibilika.

2. Isidanga soTshintsho (DS)

I-DS ibhekisa kwi-avareji yenani le-hydroxyethyl substituents kwiyunithi nganye yeglucose. Iqondo lokutshintshwa kunempembelelo ebalulekileyo kwindawo yokunyibilika, ebonakaliswa ikakhulu kule miba ilandelayo:
I-DS ephantsi: Kwi-DS ephantsi, i-hydrogen bonding phakathi kwee-molecule ze-hydroxyethyl cellulose yomelele, okwenza iimolekyuli ziboshwe ngokuqinileyo kwaye indawo yokunyibilika iphakame.

I-DS ephezulu: I-DS ephezulu yandisa ukuguquguquka kweeamolekyu kwaye inciphisa umphumo we-hydrogen bonding, okwenza ukuba ii-molecule zibe lula ukutyibilika kunye ne-melting point.

3. Ubunzima beMolekyuli

Ubunzima bemolekyuli bunefuthe elithe ngqo kwindawo yokunyibilika kwe-hydroxyethyl cellulose. Ngokuqhelekileyo, okukhona ubunzima bemolekyuli, kokukhona ikhonkco lemolekyuli lide, kokukhona amandla e-van der Waals anamandla phakathi kweemolekyuli, kwaye kokukhona inyuka indawo yokunyibilika. Ukongezelela, ububanzi bokusabalalisa ubunzima be-molecular buya kuchaphazela indawo yokunyibilika, kwaye ukusabalalisa okubanzi kunokukhokelela kumanqaku angalinganiyo okunyibilika.

Ubunzima obuphezulu bemolekyuli: Amatyathanga eemolekyuli amade, abambene ngakumbi, kwaye indawo yokunyibilika iphezulu.

Ubunzima be-molecular ephantsi: Iintambo ze-molecular zifutshane, amandla e-intermolecular abuthakathaka, kwaye indawo yokuncibilika iphantsi.

4. Ubukhazikhazi

I-Hydroxyethyl cellulose yipolymer e-amorphous, kodwa isenokuba neendawo ezithile zekristale. Ubukho bemimandla ye-crystalline kwandisa indawo yokunyibilika ngenxa yokuba isakhiwo se-crystalline sizinzile kwaye sidinga amandla amaninzi ukuphula ezi zakhiwo eziyalelweyo. Iqondo le-hydroxyethylation kunye neemeko zenkqubo zichaphazela i-crystallinity yayo.
Ubukhazikhazi obuphezulu: ubume obuqina ngakumbi, indawo ephezulu yokunyibilika.
I-crystallinity ephantsi: isakhiwo esikhululekile, indawo ephantsi yokunyibilika.

5. Ukungcola

Ngexesha lenkqubo yokuvelisa i-hydroxyethyl cellulose, ezinye izinto ezingasetyenziswanga, i-catalysts okanye iimveliso eziphumayo zingahlala. Ubukho bobu kungcola bunokutshintsha amandla e-intermolecular, ngaloo ndlela kuchaphazela indawo yokunyibilika. Umzekelo:
I-catalyst eseleyo: ii-complexes zinokuqulunqwa, ukutshintsha indawo yokunyibilika.
Iimveliso: Ubukho beemveliso ezahlukeneyo buya kutshintsha ukusebenzisana kwenkqubo kwaye kuchaphazele indawo yokunyibilika.

6. Iimeko zokusingqongileyo

Iimeko zokusingqongileyo ezifana nobushushu kunye nokufuma ziyakuchaphazela indawo yokunyibilika kwe-hydroxyethyl cellulose. Ngaphantsi kweemeko eziphakamileyo zomswakama, i-hydroxyethyl cellulose iya kuba neplastiki emva kokuthatha amanzi, okuya kunciphisa amandla e-intermolecular kunye nokunciphisa indawo yokunyibilika.
Ubushushu obuphezulu: Inokubangela ukubola kwe-thermal yezinto kunye nokwandisa indawo yokunyibilika.
Umswakama ophezulu: Ikhonkco ye-molecular iguquguquka ngakumbi emva kokufunxa amanzi, kwaye indawo yokuncibilika iyancitshiswa.

7. ITekhnoloji yoLungiso

Ubushushu, amandla okucheba, iimeko zokomisa, njl.njl ngexesha lenkqubo yokucubungula kuya kuchaphazela indawo yokunyibilika kwemveliso yokugqibela. Iimeko ezahlukeneyo zokucubungula ziya kukhokelela kwiindlela ezahlukeneyo ze-molecular orientation kunye ne-crystallinity, enokuthi ichaphazele indawo yokunyibilika.
Ubushushu bokulungisa: Amaqondo obushushu aphezulu aphezulu anokubangela ukuthotywa kwenxalenye okanye ukudibanisa, ukutshintsha indawo yokunyibilika.
Iimeko zokumisa: Ukomisa ngokukhawuleza kunye nokucotha ngokukhawuleza kuneempembelelo ezahlukeneyo kwilungiselelo leamolekyu, kwaye indawo yokunyibilika nayo iya kuhluka.

Isishwankathelo, izinto ezichaphazela i-melting point ye-hydroxyethyl cellulose ziquka i-molecular structure, i-degree of substitution, ubunzima be-molecular, i-crystallinity, ukungcola, iimeko zokusingqongileyo kunye nobuchwepheshe bokucubungula. Ukusetyenziswa okusebenzayo kunye nokucubungula, ukulawulwa okufanelekileyo kwezi zinto kunokwandisa ukusebenza kwe-hydroxyethyl cellulose kwaye kuyenze ibe ngcono ukuhlangabezana neemfuno ezahlukeneyo zokusetyenziswa. Kwinkqubo yokuvelisa, ukulungiswa kwezenzululwazi kwezi parameters akunakulawula kuphela indawo yokunyibilika kwemveliso, kodwa nokuphucula ukuzinza kunye nomgangatho wemveliso.


Ixesha lokuposa: Jul-10-2024
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