Ko te cellulose ether he pūmua hangai i hangaia mai i te cellulose tūturu hei rauemi mata mā te whakarerekētanga matū. Ko te cellulose ether he mea hanga mai i te cellulose tūturu, he rerekē te hanga cellulose ether me te pūmua hangai, ko tōna rauemi taketake ko te cellulose, he pūhui pūmua tūturu. Nā te āhua motuhake o te hanganga cellulose tūturu, kāore e taea e te cellulose tonu te tauhohe ki te kaihoko etherifying. Engari i muri i te maimoatanga o te kaihoko pupuhi, ka whakangaromia ngā hononga hauwai kaha i waenga i ngā mekameka ngota me ngā mekameka, ā, ka tukuna te mahi a te rōpū hydroxyl ki roto i te cellulose alkali me te kaha tauhohe, ā, ka whiwhi te cellulose ether mā te tauhohenga o te kaihoko etherifying - rōpū OH ki roto i te rōpū - OR.
Ko ngā āhuatanga o ngā etera cellulose e whakawhirinaki ana ki te momo, te maha me te tohatoha o ngā whakakapinga. Ko te whakarōpūtanga o te etera cellulose e hangai ana hoki ki te momo o ngā whakakapinga, te taumata o te etera, te wairewa me te tono e pā ana ka taea te whakarōpū. E ai ki te momo o ngā whakakapinga i runga i te mekameka ngota, ka taea te wehewehe ki te etera kotahi me te etera whakauru. Ko te MC te tikanga e whakamahia ana hei etera kotahi, ko te HPmc ia he etera whakauru. Ko te methyl cellulose ether MC he waeine huka toto maori i runga i te hydroxyl kua whakakapia ki te methoxide e te tātai hanganga hua [CO H7O2 (OH) 3-H (OCH3) H] X, ko te hydroxypropyl methyl cellulose ether HPmc he waeine i runga i te hydroxyl he wāhanga o te methoxide kua whakakapia, ko tētahi atu wāhanga o te hua hydroxypropyl kua whakakapia. Ko te tātai hanganga ko [C6H7O2 (OH) 3-MN (OCH3) M [OCH2CH (OH) CH3] N] X me te hydroxyethyl methyl cellulose ether HEmc, e whakamahia whānuitia ana, e hokona ana hoki i te mākete.
Mai i te wairewatanga ka taea te wehewehe ki te momo ionic me te momo kore-ionic. Ko te cellulose ether kore-ionic wairewa-wai ko te nuinga o te tito o te alkyl ether me te hydroxyl alkyl ether e rua ngā momo. Ko te Cmc ionic te nuinga o te whakamahinga i roto i te hopi hangai, te kakahu, te tā, te kai me te hinu. Ko te MC kore-ionic, HPmc, HEmc me ētahi atu e whakamahia ana i roto i ngā rauemi hanga, ngā paninga rapa, te rongoā, te matū o ia rā me ētahi atu āhuatanga. Hei kaihoko whakamātotoru, kaihoko pupuri wai, kaiwhakaū, kaihoko whakamarara, kaihoko hanga kiriata.
Te pupuri wai o te cellulose ether
I roto i te hanga rauemi hanga, inā koa te moata maroke, he mahi nui te cellulose ether, inā koa i roto i te hanga moata motuhake (moata whakarerekētia), he wāhanga nui.
Ko te tūranga nui o te cellulose ether wairewa-wai i roto i te moata te nuinga o ngā āhuatanga e toru, ko te tuatahi he kaha pupuri wai pai, ko te tuarua ko te awe o te ōritetanga moata me te thixotropy, ko te tuatoru ko te taunekeneke ki te sima.
Ko te pupuri wai o te cellulose ether, e whakawhirinaki ana ki te pūtake o te hydroscopicity, te hanganga o te moata, te matotoru o te paparanga moata, te hiahia wai moata, me te wā whakatōtō rauemi. Ko te pupuri wai o te cellulose ether i ahu mai i te wairewatanga me te maroketanga o te cellulose ether tonu. E mōhiotia whānuitia ana ko ngā mekameka ngota cellulose, ahakoa he nui ngā rōpū OH tino makuku kei roto, kāore e wairewa i roto i te wai nā te mea he tino tioata. Kāore te kaha whakamakuku o ngā rōpū hydroxyl anake e ranea hei utu mō ngā here hauwai kaha me ngā kaha van der Waals. Ina whakaurua ngā whakakapinga ki roto i te mekameka ngota, ehara i te mea ko ngā whakakapinga anake ka whakangaro i te mekameka hauwai, engari ko ngā here hauwai mekameka hoki ka pakaru nā te hononga o ngā whakakapinga i waenga i ngā mekameka tata. Ko te nui ake o ngā whakakapinga, ko te tawhiti i waenga i ngā ngota. Ko te nui ake o te pānga o te whakangaromanga o te here hauwai, ka whānui te whatunga cellulose, ka wairewa te otinga ki roto i te cellulose ether, ka hangaia he otinga matotoru teitei. I te pikinga o te pāmahana, ka heke te whakamakuku o te polymer, ā, ka peia te wai i waenga i ngā mekameka. Ina rawaka te pānga whakamaroke, ka tīmata te whakakotahi i ngā ngota, ka takai te tiēre hei whatunga toru-ahu. Ko ngā āhuatanga e pā ana ki te pupuri wai o te moata ko te matotoru o te cellulose ether, te inenga, te matotoru o te matūriki me te pāmahana ratonga.
Ko te nui ake o te matotoru o te cellulose ether, ko te pai ake o te mahi pupuri wai, ko te matotoru o te otinga polymer. Ko te taumaha ngota (te nekehanga o te polymerization) o te polymer ka whakatauhia hoki e te roa me te āhua o te hanganga ngota o te mekameka, ā, ko te tohatoha o te maha o ngā whakakapinga ka pā tika ki te whānuitanga matotoru. [eta] = Km alpha
Te matotoru ā-roto o ngā otinga polymer
Taumaha ngota ngota M
pūmau āhuatanga pūmua α
Tauwehenga otinga matotoru K
Ko te matotoru o te otinga polymer e whakawhirinaki ana ki te taumaha ngota o te polymer. Ko te matotoru me te kukū o ngā otinga cellulose ether e pā ana ki ngā tono maha. Nō reira, he maha ngā whakatakotoranga matotoru rerekē o ia cellulose ether, ko te whakahaere matotoru hoki ko te nuinga mā te whakahekenga o te cellulose alkali, arā, ko te whati o te mekameka ngota cellulose hei whakatutuki.
Mō te rahi o te matūriki, ko te angiangi o te matūriki, ko te pai ake o te pupuri wai. Ina pa atu ngā matūriki nui o te cellulose ether ki te wai, ka memeha tonu te mata ka hanga he kirikiri hei takai i te rauemi kia kore ai e uru tonu ngā ngota wai, i ētahi wā ka kore e taea te whakamarara noa i te wa roa, ka puta he wairewa paru, he wai whakapūpū rānei. Ko te wairewa o te cellulose ether tētahi o ngā mea hei whiriwhiri i te cellulose ether.
Te whakamātotoru me te thixotropy o te cellulose ether
Ko te tuarua o ngā pānga o te cellulose ether – ko te matotoru ka whakawhirinaki ki: te tohu polymerization cellulose ether, te kukū o te otinga, te tere kutikuti, te pāmahana me ētahi atu āhuatanga. He ahurei te āhuatanga gelation o te otinga ki te alkyl cellulose me ōna hua kua whakarerekētia. E pā ana ngā āhuatanga gelation ki te tohu o te whakakapinga, te kukū o te otinga me ngā tāpiringa. Mō ngā hua kua whakarerekētia te hydroxyl alkyl, e pā ana hoki ngā āhuatanga gel ki te tohu o te whakarerekētanga hydroxyl alkyl. Mō te kukū o te otinga o te MC me te HPmc matotoru iti ka taea te whakarite i te otinga kukū 10%-15%, ka taea te whakarite i te MC me te HPmc matotoru reo 5%-10% te otinga ā, ka taea te whakarite i te MC me te HPmc matotoru teitei 2%-3% anake te otinga, ā, ko te tikanga ka whakarōpūhia te matotoru o te cellulose ether e te otinga 1%-2%. He nui te kaha o te whakamaroke o te cellulose ether taumaha ngota, he rite te kukū o te otinga, he rerekē te matotoru o ngā polymer taumaha ngota rerekē, ka taea te whakaatu i te matotoru me te taumaha ngota penei, [η]=2.92×10-2 (DPn) 0.905, ko te DPn te tohu polymerization toharite o te teitei. Me tāpiri atu te cellulose ether taumaha ngota iti hei whakatutuki i te matotoru whainga. He iti ake te whakawhirinaki o tōna matotoru ki te tere kutikuti, he nui te matotoru hei whakatutuki i te matotoru whainga, ko te nui e hiahiatia ana hei tāpiri iti, ko te matotoru e whakawhirinaki ana ki te pai o te whakamaroke. Nō reira, hei whakatutuki i tētahi ōritetanga, me whakarite he nui o te cellulose ether (te kukū o te otinga) me te matotoru o te otinga. Ka heke te pāmahana gelation o te otinga i te taha rārangi me te pikinga o te kukū o te otinga, ā, ka puta te gelation i te pāmahana rūma i muri i te taenga ki tētahi kukū. He nui te kukū gelation o te HPmc i te pāmahana rūma.
Ka taea hoki te whakarerekē i te ōritetanga mā te whiriwhiri i te rahi o te matūriki me ngā etera cellulose me ngā nekehanga whakarerekētanga rerekē. Ko te mea e kiia nei ko te whakarerekētanga ko te whakaurunga o te rōpū hydroxyl alkyl ki tētahi nekehanga whakakapinga ki te hanganga anga o te MC. Mā te whakarerekē i ngā uara whakakapinga whanaunga o ngā whakakapinga e rua, arā, ko ngā uara whakakapinga whanaunga DS me MS o ngā rōpū methoxy me te hydroxyl. E hiahiatia ana ngā āhuatanga rerekē o te etera cellulose mā te whakarerekē i ngā uara whakakapinga whanaunga o ngā momo whakakapinga e rua.
te whanaungatanga i waenga i te ōritetanga me te whakarerekētanga. I te Pikitia 5, ka pā te tāpiri o te cellulose ether ki te wai e pau ana i te moata, ā, ka huri i te ōwehenga wai-here o te wai me te sima, arā, te pānga matotoru. Ko te nui ake o te horopeta, ko te nui ake o te wai e pau ana.
Me tere te memeha o ngā etera cellulose e whakamahia ana i roto i ngā rauemi hanga paura ki te wai matao, kia tika ai te hanganga o te pūnaha. Mēnā he mātotoru tonu, he korōria tonu te tere kutikuti, he hua kounga iti iho rānei.
He pai hoki te whanaungatanga rārangi i waenga i te ōritetanga o te paru sima me te horopeta o te cellulose ether, ka taea e te cellulose ether te whakanui ake i te matotoru o te moata, ko te nui ake o te horopeta, ko te kitea ake o te pānga.
He nui te thixotropy o te wairewa wai cellulose ether me te matotoru teitei, koinei tētahi o ngā āhuatanga o te cellulose ether. Ko ngā wairewa wai o ngā polymer momo Mc he maha ngā wā he pseudoplastic, he kore-thixotropic fluidity i raro i tō rātou pāmahana gel, engari ko ngā āhuatanga rere Newtonian i ngā tere kutikuti iti. Ka piki ake te pseudoplasticity me te pikinga o te taumaha ngota, te kukū rānei o te cellulose ether, ā, kāore e pā ki te momo me te tohu whakakapinga. Nō reira, ko ngā cellulose ether o te taumata matotoru ōrite, ahakoa MC, HPmc, HEmc rānei, e whakaatu tonu ana i ngā āhuatanga rheological ōrite i te mea kei te mau tonu te kukū me te pāmahana. Ina piki te pāmahana, ka hangaia he gel hanganga, ā, ka puta he rere thixotropic teitei. Ko ngā cellulose ether me te kukū teitei me te matotoru iti e whakaatu ana i te thixotropy ahakoa i raro i te pāmahana gel. He tino painga tēnei āhuatanga ki te hanganga o te moata hanga hei whakatika i tōna rere me tōna āhuatanga iri rere. Me whakamārama i konei ko te teitei ake o te matotoru o te cellulose ether, ka pai ake te pupuri wai, engari ko te teitei ake o te matotoru, ka teitei ake te taumaha ngota whanaunga o te cellulose ether, ka heke te wairewa, ka pā kino ki te kukū o te moata me te mahi hanga. Ko te teitei ake o te matotoru, ka kitea te pānga matotoru o te moata, engari ehara i te mea he whanaungatanga ōrite katoa. He iti te matotoru o ētahi, engari he pai ake te mahi a te cellulose ether kua whakarerekētia ki te whakapai ake i te kaha hanganga o te moata mākū, me te pikinga ake o te matotoru, ka pai ake te pupuri wai o te cellulose ether.
Wā tuku: Maehe-30-2022