Yintoni iHydroxypropyl Methylcellulose Yenziwe Ngayo

I-Hydroxypropyl methylcellulose (HPMC) i-polymer ye-semisynthetic esetyenziswa kuluhlu olubanzi lwamashishini, kuquka ukwakhiwa, ukutya, amayeza, kunye neemveliso zokunyamekela komntu. Ixabiswa ngenxa yokukwazi ukuphucula iimpawu ze-rheological zokuqulunqa, kunye nokuhambelana kwayo nezinye izithako kunye netyhefu ephantsi. Ukuqonda indlela eyenziwa ngayo i-HPMC, kubalulekile ukuqonda kuqala isakhiwo kunye neempawu zeselulosi.

I-Cellulose yitsheyina elide leemolekyuli zeglucose ezifumaneka kwiindonga zeeseli zezityalo. Iimolekyuli ze-glucose zidityaniswe kunye neebhondi ze-beta-1,4-glycosidic, zenza ikhonkco lomgca. La matyathanga ke adityaniswe ziibhondi ze-hydrogen kunye nemikhosi kaVan der Waals ukuze zenze izakhiwo ezomeleleyo, ezinentsinga. I-Cellulose yeyona nto ininzi emhlabeni, kwaye isetyenziswa kuluhlu olubanzi lwezicelo, kubandakanya iphepha, amalaphu, kunye nezinto zokwakha.

Ngelixa i-cellulose ineempawu ezininzi eziluncedo, ihlala iqinile kwaye ayinyibiliki ukuba isetyenziswe kumachiza amaninzi. Ukoyisa le mida, izazinzulu ziye zaphuhlisa inani lezinto eziphuma kwi-cellulose ezilungisiweyo, kuquka i-HPMC. I-HPMC yenziwa ngokuguqula i-cellulose yendalo ngothotho lweempendulo zemichiza.

Inyathelo lokuqala ekwenzeni i-HPMC kukufumana imathiriyeli yokuqala yeselulosi. Oku kunokwenziwa ngokukhupha i-cellulose kwimithombo yezityalo efana ne-pulp yamaplanga, umqhaphu, okanye i-bamboo. Emva koko i-cellulose iphathwa ngesisombululo se-alkaline, njenge-sodium hydroxide okanye i-potassium hydroxide, ukususa ukungcola kunye nokudiliza imicu ye-cellulose ibe ngamancinci amancinci. Le nkqubo yaziwa ngokuba yi-mercerization, kwaye yenza i-cellulose isebenze ngakumbi kwaye kulula ukuyiguqula.

Emva kwe-mercerization, i-cellulose iphendulwa ngomxube we-propylene oxide kunye ne-methyl chloride ukwazisa i-hydroxypropyl kunye namaqela e-methyl kumqolo we-cellulose. Amaqela e-hydroxypropyl ayongezwa ekuphuculeni ukunyibilika kunye nokugcinwa kwamanzi kwiipropati ze-cellulose, ngelixa amaqela e-methyl adityaniswa ukwandisa ukuzinza kunye nokunciphisa ukuphinda kusebenze i-cellulose. Ukusabela ngokuqhelekileyo kwenziwa phambi kwe-catalyst, efana ne-sodium hydroxide okanye i-potassium hydroxide, kwaye phantsi kweemeko ezilawulwayo zobushushu, uxinzelelo kunye nexesha lokuphendula.

Iqondo lokuthatha indawo (DS) le-HPMC libhekiselele kwinani le-hydroxypropyl kunye namaqela e-methyl athe aziswa kumqolo we-cellulose. I-DS inokwahluka ngokuxhomekeke kwiipropati ezifunwayo ze-HPMC kunye nesicelo esithile esetyenziselwa sona. Ngokubanzi, amaxabiso aphezulu e-DS abangela ukuba i-HPMC ibe ne-viscosity esezantsi kunye namazinga okupheliswa ngokukhawuleza, ngelixa amaxabiso aphantsi e-DS ekhokelela kwi-HPMC ene-viscosity ephezulu kunye namazinga acothayo okupheliswa.

Emva kokuba impendulo igqityiwe, imveliso ephumayo iyahlanjululwa kwaye yomiswe ukwenza i-HPMC powder. Inkqubo yokucoca ibandakanya ukususa naziphi na iikhemikhali ezingaphendulwanga, izinyibilikisi ezishiyekileyo, kunye nobunye ukungcola kwi-HPMC. Oku kwenziwa ngokudityaniswa kwamanyathelo okuhlamba, ukuhluza, kunye nokomisa.

Imveliso yokugqibela ngumgubo omhlophe ukuya komhlophe ongenavumba kwaye ongenancasa. I-HPMC iyanyibilika emanzini kunye nezinyibilikisi ezininzi eziphilayo, kwaye inokwenza iijeli, iifilimu, kunye nezinye izakhiwo ngokuxhomekeke kwiimeko zokusetyenziswa. Yipolymer engeyiyo i-ionic, oku kuthetha ukuba ayithwali nayiphi na intlawulo yombane, kwaye ngokuqhelekileyo ithathwa njengento engeyona ityhefu kwaye ikhuselekile ukusetyenziswa kuluhlu olubanzi lwezicelo.

I-HPMC isetyenziswa kuluhlu olubanzi lokuqulunqwa, kuquka iipeyinti, izinto zokuncamathelisa, izitywini, amayeza, kunye neemveliso zokutya. Kwizicelo zokwakha, i-HPMC isoloko isetyenziswa njenge-thickener, binder, kunye nefilimu-yangaphambili kwiimveliso zesamente kunye ne-gypsum-based, ezifana nodaka, i-grouts, kunye neekhompawundi ezidibeneyo.