Yintoni indawo yokunyibilika ye-HPMC?

IHydroxypropyl methylcellulose (HPMC) yi-semi-synthetic, i-polymer enyibilikayo emanzini ephuma kwi-cellulose. Isetyenziswa kakhulu kumashishini ahlukeneyo, kubandakanya amayeza, ukutya, ulwakhiwo, kunye nezinto zokuthambisa, ngenxa yeempawu zayo ezizodwa ezinjengokuqina, ukubopha, ukwenza ifilimu, kunye nokuzinzisa. Nangona kunjalo, kubalulekile ukuqaphela ukuba i-HPMC ayinayo indawo yokunyibilika ethile kuba ayihambi kwinkqubo yokwenyani yokunyibilika njengezixhobo zekristale. Endaweni yoko, ifumana inkqubo yokuthotywa kwe-thermal xa ishushu.

1. Iipropati ze-HPMC:
I-HPMC yimpuphu emhlophe ukuya emhlophe engenavumba, enyibilikayo emanzini kunye nezinyibilikisi ezininzi eziphilayo. Iimpawu zayo ziyahluka ngokuxhomekeke kwizinto ezifana neqondo lokutshintshela (DS), ubunzima bemolekyuli, kunye nokusabalalisa ubungakanani besuntswana. Ngokubanzi, ibonisa ezi mpawu zilandelayo:

Ubume be-non-ionic: I-HPMC ayithwali nayiphi na intlawulo yombane kwisisombululo, iyenza ihambelane noluhlu olubanzi lwezinye izinto.
Ukwenziwa kwefilimu: I-HPMC inokwenza iifilimu ezicacileyo, eziguquguqukayo xa zomile, ezifumana izicelo kwiingubo, iifilimu, kunye neefom zedosi ezilawulwayo kumayeza.
I-ejenti yokutyebisa: Inika i-viscosity kwizisombululo, iyenza ibe luncedo kwiimveliso zokutya, izinto zokuthambisa, kunye namayeza.
I-Hydrophilic: I-HPMC inobudlelwane obuphezulu bamanzi, obunegalelo ekunyibilikeni kwayo kunye neempawu zokwenza ifilimu.

2. Ukwenziwa kwe-HPMC:
I-HPMC idityaniswe ngothotho lweempendulo zemichiza ezibandakanya i-cellulose, ipropylene oxide, kunye ne-methyl chloride. Inkqubo ibandakanya i-etherification ye-cellulose kunye nepropylene oxide elandelwa yi-methylation kunye ne-methyl chloride. Iqondo lokutshintshwa (DS) lwe-hydroxypropyl kunye namaqela e-methoxy anokulawulwa ukulungisa iimpawu ze-HPMC enesiphumo.

3. Usetyenziso lwe-HPMC:
Umzi-mveliso wamachiza: I-HPMC isetyenziswa ngokubanzi njenge-excipient kwi-formulations yamayeza, kubandakanywa iipilisi, ii-capsules, izisombululo zamehlo, kunye neefom zedosi elawulwayo.
Umzi-mveliso wokutya: Isetyenziswa njenge-thickener, stabilizer, kunye ne-emulsifier kwiimveliso zokutya ezifana neesosi, isuphu, ii-ice creams, kunye nezinto zokubhaka.
Ishishini lokwakha: I-HPMC yongezwa kwiimveliso ezisekwe kwisamente ukuphucula ukusebenza, ukugcinwa kwamanzi, kunye nokuncamathela. Ikwasetyenziselwa ukuncamathelisa iithayile, udaka, kunye nonikezelo.
Umzi-mveliso wezithambiso: I-HPMC isetyenziswa kwiindlela ezahlukeneyo zokuthambisa ezifana neekhrimu, izinto zokuthambisa, kunye neeshampu zokujiya nokuzinzisa iipropati.

4. Ukuziphatha kweThermal ye-HPMC:
Njengoko bekutshiwo ngaphambili, i-HPMC ayinayo indawo yokunyibilika ethile ngenxa yobume bayo be-amorphous. Endaweni yoko, ifumana ukuthotywa kwe-thermal xa ishushu. Inkqubo yokwehlisa umgangatho ibandakanya ukuqhawuka kwamabhondi ekhemikhali ngaphakathi kwekhonkco lepolymer, okukhokelela ekwakhekeni kweemveliso zokubola okuguquguqukayo.

Ukushisa kokuthotywa kwe-HPMC kuxhomekeke kwizinto ezininzi, kuquka ubunzima bayo bemolekyuli, iqondo lokuthatha indawo, kunye nobukho bezongezo. Ngokuqhelekileyo, ukuthotywa kwe-thermal ye-HPMC iqala malunga ne-200 ° C kwaye iqhubela phambili ngokunyuka kweqondo lokushisa. Iprofayili yokuthotywa ingahluka kakhulu ngokuxhomekeke kwibakala elithile le-HPMC kunye nezinga lokufudumeza.

Ngexesha lokuthotywa kwe-thermal, i-HPMC iqhuba iinkqubo ezininzi ezihambelanayo, kubandakanywa ukuchithwa kwamanzi, ukuchithwa kwe-depolymerization, kunye nokubola kwamaqela asebenzayo. Iimveliso eziphambili zokubola ziquka amanzi, i-carbon dioxide, i-carbon monoxide, i-methanol, kunye nee-hydrocarbons ezahlukeneyo.

5. IiTeknikhi zokuHlalutya iThermal ze-HPMC:
Ukuziphatha okushushu kwe-HPMC kunokufundwa kusetyenziswa iindlela ezahlukeneyo zohlalutyo, kubandakanya:
Uhlalutyo lwe-Thermogravimetric (TGA): I-TGA ilinganisa ukulahleka kwesisindo sesampuli njengomsebenzi weqondo lokushisa, inika ulwazi malunga nokuzinza kwayo kwe-thermal kunye ne-kinetics yokubola.
I-calorimetry yokuskena eyahlukileyo (i-DSC): I-DSC ilinganisa ukuhamba kobushushu ngaphakathi okanye ngaphandle kwesampulu njengomsebenzi weqondo lokushisa, okuvumela ukubonakaliswa kweenguqu zesigaba kunye neziganeko ze-thermal ezifana nokunyibilika kunye nokuthotywa.
I-Fourier-transform infrared spectroscopy (FTIR): I-FTIR ingasetyenziselwa ukujonga utshintsho lweekhemikhali kwi-HPMC ngexesha lokuthotywa kwe-thermal ngokuhlalutya utshintsho kumaqela asebenzayo kunye nesakhiwo se-molecular.

6. Isiphelo:
I-HPMC yipolymer eguquguqukayo enoluhlu olubanzi lwezicelo kumayeza, ukutya, ukwakhiwa, kunye nezithambiso. Ngokungafaniyo nezixhobo zekristale, i-HPMC ayinayo indawo yokunyibilika ethile kodwa ifumana ukuthotywa kwe-thermal xa ishushu. Iqondo lobushushu elithotyiweyo lixhomekeke kwizinto ezahlukeneyo kwaye ngokuqhelekileyo liqala malunga nama-200°C. Ukuqonda ukuziphatha kwe-thermal ye-HPMC kubalulekile kulawulo lwayo olufanelekileyo kunye nokucubungula kumashishini ahlukeneyo.