Kuchuluka kwa efa ya cellulose

Ma ether a celluloseNdi gulu la ma polima osiyanasiyana omwe amagwiritsidwa ntchito kwambiri m'mafakitale osiyanasiyana chifukwa cha mphamvu zawo zokhuthala. Kuyambira ndi chiyambi cha ma ether a cellulose ndi kapangidwe kawo, pepalali likufotokoza momwe zimagwirira ntchito pokhuthala, kufotokoza momwe kuyanjana ndi mamolekyu amadzi kumathandizira kuti ma viscosity achuluke. Mitundu yosiyanasiyana ya ma ether a cellulose ikukambidwa, kuphatikizapo methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, ndi carboxymethyl cellulose, iliyonse ili ndi mawonekedwe apadera okhuthala. kugwiritsa ntchito ma ether a cellulose m'mafakitale monga zomangamanga, mankhwala, chakudya, zodzoladzola, ndi chisamaliro chaumwini, kuwonetsa udindo wawo wofunikira kwambiri pakupanga zinthu ndi njira zopangira. Pomaliza, kufunika kwa ma ether a cellulose m'mafakitale amakono kukugogomezeredwa, pamodzi ndi ziyembekezo zamtsogolo komanso kupita patsogolo kwaukadaulo wa ether wa cellulose.

Ma ether a cellulose amaimira gulu la ma polima ochokera ku cellulose, biopolymer yomwe imapezeka kwambiri m'makoma a maselo a zomera. Ndi mphamvu zapadera za physicochemical, ma ether a cellulose amagwiritsidwa ntchito kwambiri m'mafakitale osiyanasiyana, makamaka chifukwa cha mphamvu zawo zokhuthala. Kuthekera kwa ma ether a cellulose kuwonjezera kukhuthala ndikuwongolera mphamvu za rheological kumapangitsa kuti akhale ofunikira kwambiri pazinthu zosiyanasiyana kuyambira pa zipangizo zomangira mpaka kupanga mankhwala.

1. Kapangidwe ka Cellulose Ethers

Musanafufuze za kuchuluka kwa ma cellulose ethers, ndikofunikira kumvetsetsa kapangidwe kawo. Ma cellulose ethers amapangidwa kudzera mu kusintha kwa mankhwala a cellulose, makamaka chifukwa cha kusintha kwa etherification. Magulu a hydroxyl (-OH) omwe ali mu msana wa cellulose amakumana ndi kusintha kwa ethers ndi magulu a ether (-OR), pomwe R imayimira zinthu zosiyanasiyana. Kusintha kumeneku kumabweretsa kusintha kwa kapangidwe ka mamolekyulu ndi katundu wa cellulose, zomwe zimapangitsa kuti ma cellulose ethers akhale ndi makhalidwe osiyana.

Kusintha kwa kapangidwe ka ma cellulose ethers kumakhudza kusungunuka kwawo, khalidwe la rheological, ndi mphamvu zokhuthala. Mlingo wa kusintha (DS), womwe umatanthauza kuchuluka kwa magulu a hydroxyl omwe amasinthidwa pa unit iliyonse ya anhydroglucose, umagwira ntchito yofunika kwambiri pozindikira mphamvu za ma cellulose ethers. DS yapamwamba nthawi zambiri imagwirizana ndi kuwonjezeka kwa kusungunuka ndi mphamvu zokhuthala.

2. Njira Zolimbikitsira Kukhuthala

Kukhuthala komwe kumawonetsedwa ndi ma cellulose ethers kumachokera ku kuyanjana kwawo ndi mamolekyu amadzi. Akamwazikana m'madzi, ma cellulose ethers amalowa mumadzi, momwe mamolekyu amadzi amapangira ma hydrogen bond ndi ma atomu a ether oxygen ndi magulu a hydroxyl a ma polymer chains. Njira yothira madzi iyi imabweretsa kutupa kwa tinthu ta cellulose ether ndikupangidwa kwa kapangidwe ka netiweki yamitundu itatu mkati mwa medium yamadzi.

Kumangika kwa unyolo wa ether wa cellulose wosungunuka komanso kupangika kwa ma hydrogen bond pakati pa ma polymer molecules kumathandiza kuti ma viscosity achuluke. Kuphatikiza apo, kukana kwa electrostatic pakati pa magulu a ether omwe ali ndi mphamvu yoipa kumathandizanso kukhuthala mwa kupewa kulongedzana kwa unyolo wa polima ndikulimbikitsa kufalikira mu solvent.

Khalidwe la rheological la ma cellulose ether solutions limakhudzidwa ndi zinthu monga kuchuluka kwa polymer, kuchuluka kwa kusintha, kulemera kwa mamolekyulu, ndi kutentha. Pa kuchuluka kochepa, ma cellulose ether solutions amasonyeza khalidwe la Newtonian, pomwe pa kuchuluka kwakukulu, amasonyeza khalidwe la pseudoplastic kapena shear-thinning chifukwa cha kusokonezeka kwa ma polymer entanglements omwe amakhudzidwa ndi shear stress.

3. Mitundu ya Cellulose Ethers
Ma ether a cellulose amakhala ndi mitundu yosiyanasiyana ya zinthu zotumphukira, iliyonse ili ndi mphamvu zake zokhuthala zoyenera kugwiritsidwa ntchito m'njira zosiyanasiyana. Mitundu ina ya ma ether a cellulose omwe amagwiritsidwa ntchito kwambiri ndi awa:

Methyl Cellulose (MC): Methyl cellulose imapezeka poika ether ya cellulose m'magulu a methyl. Imasungunuka m'madzi ozizira ndipo imapanga mayankho owoneka bwino komanso okhuthala. MC ili ndi mphamvu zabwino zosungira madzi ndipo imagwiritsidwa ntchito kwambiri ngati chokhuthala mu zipangizo zomangira, zokutira, ndi zakudya.

Hydroxyethyl Cellulose (HEC): Hydroxyethyl cellulose ndi yopangidwa

Imasungunuka m'madzi ozizira komanso otentha ndipo imasonyeza khalidwe lopanda pake. HEC imagwiritsidwa ntchito kwambiri popanga mankhwala, zinthu zosamalira thupi, komanso ngati chokhuthala mu utoto wa latex.

Hydroxypropyl Cellulose (HPC): Hydroxypropyl cellulose imakonzedwa mwa kusakaniza cellulose ndi magulu a hydroxypropyl. Imasungunuka m'mitundu yosiyanasiyana ya zosungunulira, kuphatikizapo madzi, mowa, ndi zosungunulira zachilengedwe. HPC imagwiritsidwa ntchito kwambiri ngati chokhuthala, chomangirira, komanso chopangira filimu m'mankhwala, zodzoladzola, ndi zokutira.

Carboxymethyl Cellulose (CMC): Carboxymethyl cellulose imapangidwa ndi carboxymethylation ya cellulose ndi chloroacetic acid kapena sodium salt yake. Imasungunuka kwambiri m'madzi ndipo imapanga mayankho okhuthala okhala ndi khalidwe labwino kwambiri la pseudoplastic. CMC imagwiritsidwa ntchito kwambiri mu zakudya, mankhwala, nsalu, ndi kupanga mapepala.

Ma ether a cellulose awa ali ndi mphamvu zosiyana zokhuthala, kusungunuka, komanso kugwirizana ndi zosakaniza zina, zomwe zimapangitsa kuti zikhale zoyenera kugwiritsidwa ntchito m'mafakitale osiyanasiyana.

4. Kugwiritsa ntchito ma Cellulose Ethers
Kapangidwe kake kolimba ka ma cellulose ethers kamapangitsa kuti akhale ofunikira kwambiri m'mafakitale osiyanasiyana. Ntchito zina zofunika kwambiri za ma cellulose ethers ndi izi:

Zipangizo Zomangira: Ma cellulose ether amagwiritsidwa ntchito kwambiri ngati zowonjezera mu zinthu zopangidwa ndi simenti monga matope, grout, ndi pulasitala kuti zigwire bwino ntchito, kusunga madzi, komanso kumamatira. Amagwira ntchito ngati zosinthira rheology, kupewa kulekanitsa ndikuwonjezera magwiridwe antchito a zinthu zomangira.

Mankhwala: Ma cellulose ether amagwiritsidwa ntchito kwambiri mu mankhwala monga zomangira, zosungunula, ndi zokhuthala m'mapiritsi, makapisozi, zosungunula, ndi mayankho a maso. Amawongolera kayendedwe ka ufa, amathandizira kupsinjika kwa mapiritsi, komanso amawongolera kutulutsa kwa zosakaniza zogwira ntchito.

Zakudya: Ma cellulose ether nthawi zambiri amagwiritsidwa ntchito ngati zinthu zokhuthala, zokhazikika, komanso zoyeretsera m'zakudya zosiyanasiyana, kuphatikizapo sosi, zodzoladzola, zokometsera, ndi mkaka. Amawonjezera kapangidwe kake, kukhuthala, ndi kumva bwino mkamwa pamene akulimbitsa kukhazikika kwa shelufu ndikuletsa syneresis.

Zodzoladzola ndi Kusamalira Munthu: Ma ether a cellulose amagwiritsidwa ntchito mu zodzoladzola ndi zinthu zosamalira munthu monga mafuta, mafuta odzola, ma shampu, ndi mankhwala otsukira mano monga zokhuthala, zosakaniza, ndi zinthu zopangira filimu. Amapereka mphamvu zabwino za rheological, amalimbitsa kukhazikika kwa chinthucho, komanso amapereka mawonekedwe osalala komanso apamwamba.

Utoto ndi Zophimba:Ma ether a celluloseAmathandiza ngati zinthu zosinthira rheology mu utoto, zokutira, ndi zomatira, kukonza kulamulira kwa kukhuthala, kukana kutsika, komanso kupanga filimu. Amathandizira kukhazikika kwa mapangidwe, amaletsa kukhazikika kwa utoto, komanso amawonjezera mphamvu zogwiritsira ntchito.

Kukhuthala kwa ma cellulose ethers kumachita gawo lofunika kwambiri m'mafakitale osiyanasiyana komanso popanga zinthu. Kapangidwe kawo kapadera ka rheological, kugwirizana ndi zosakaniza zina, komanso kuwonongeka kwa zinthu zimapangitsa kuti zikhale zosankha zabwino kwa opanga m'magawo osiyanasiyana. Pamene mafakitale akupitilizabe kuyika patsogolo njira zokhazikika komanso zosamalira chilengedwe, kufunikira kwa ma cellulose ethers kukuyembekezeka kukwera kwambiri.