Hydroxyethyl cellulose (HEC)tseem nyob hauv dej tau zoo heev ntawm ntau qhov kub thiab txias, txawm tias nyob hauv thaj chaw kub siab uas lwm cov cellulose ethers uas tsis yog ionic hloov kho xws li methyl cellulose (MC) thiab hydroxypropyl methyl cellulose (HpMC) muaj cov ntsiab lus turbidity. Txhawm rau piav qhia qhov ua rau muaj kev solubility siab ntawm HEC, qhov kub thiab txias ntawm cov dej sib xyaw nH rau txhua chav glucopyran hauv HEC cov qauv tau kuaj xyuas dhau qhov kub thiab txias hauv qab no txij li 10 txog 70 ° C siv cov ntsuas dielectric spectrum siab heev txog li 50 GHz.
Hauv txoj kev tshawb no, cov qauv HEC tau kuaj xyuas rau tus lej molar ntawm hydroxyethyl substitutions (MS) ntawm txhua chav glucose pyran xws li 1.3 txog 3.6. Tag nrho cov qauv HEC tau yaj hauv dej hauv qhov kub thiab txias uas tau kuaj xyuas thiab tsis pom cov ntsiab lus turbidity. Tus nqi nH ntawm HEC cov qauv nrog MS 1.3 yog 14 ntawm 20 ° C, thiab txo qis qeeb nrog qhov kub nce, thiab poob rau 10 ntawm 70 ° C. Tus nqi PH ntawm HEC qauv yog qhov loj dua qhov tsawg kawg nkaus tseem ceeb nH tus nqi ntawm kwv yees li. 5 Cellulose ethers xws li MC thiab HpMC yuav tsum tau yaj hauv dej, txawm tias nyob rau hauv qhov kub siab.
Txawm li cas los xij, HEC cov molecule yog cov dej-soluble hla ntau qhov kub thiab txias. Qhov kub nyob ntawm nH ntawm HEC cov qauv thiab triglycol (qauv sib xyaw ntawm HEC substituents) yog qhov tsis hnyav thiab lawv zoo sib xws. Qhov kev soj ntsuam no qhia tau hais tias tus cwj pwm hydration / dehydration ntawm HEC cov qauv feem ntau yog tswj hwm los ntawm lawv cov pab pawg hloov. 3 yog 14 ntawm 20 ° C, poob qis qeeb thaum qhov kub nce, thiab poob rau 10 ntawm 70 ° C. Tus nqi nH ntawm HEC qauv yog qhov loj dua qhov tsawg kawg nkaus tseem ceeb nH tus nqi ntawm kwv yees li. 5 Cellulose ethers xws li MC thiab HpMC yuav tsum tau yaj hauv dej, txawm tias nyob rau hauv qhov kub siab. Txawm li cas los xij, HEC cov molecule yog cov dej-soluble hla ntau qhov kub thiab txias. Qhov kub nyob ntawm nH ntawm HEC cov qauv thiab triglycol (qauv sib xyaw ntawm HEC substituents) yog qhov tsis hnyav thiab lawv zoo sib xws rau ib leeg.
Qhov kev soj ntsuam no qhia tau hais tias tus cwj pwm hydration / dehydration ntawm HEC cov qauv feem ntau yog tswj hwm los ntawm lawv cov pab pawg hloov pauv. 3 yog 14 ntawm 20 ° C, poob qis qeeb thaum qhov kub nce, thiab poob rau 10 ntawm 70 ° C. Tus nqi nH ntawm HEC qauv yog qhov loj dua qhov tsawg kawg nkaus tseem ceeb nH tus nqi ntawm kwv yees li. 5 Cellulose ethers xws li MC thiab HpMC yuav tsum tau yaj hauv dej, txawm tias nyob rau hauv qhov kub siab. Txawm li cas los xij, HEC molecules yog dej-soluble hla ntau qhov kub thiab txias. Qhov kub nyob ntawm nH ntawmHECcov qauv thiab triglycol (cov qauv sib xyaw ntawm HEC substituents) yog qhov tsis hnyav thiab lawv zoo sib xws. Qhov kev soj ntsuam no qhia tau hais tias tus cwj pwm hydration / dehydration ntawm HEC cov qauv feem ntau yog tswj hwm los ntawm lawv cov pab pawg hloov pauv.
Tus nqi nH ntawm HEC qauv yog qhov tseeb loj dua qhov tsawg kawg nkaus tseem ceeb nH tus nqi ntawm kwv yees li. 5 Cellulose ethers xws li MC thiab HpMC yuav tsum tau yaj rau hauv dej, txawm tias nyob rau hauv qhov kub siab. Txawm li cas los xij, HEC molecules yog dej-soluble hla ntau qhov kub thiab txias. Qhov kub nyob ntawm nH ntawm HEC qauv thiab triglycol (qauv sib xyaw ntawm HEC substituents) yog me me thiab lawv zoo sib xws rau ib leeg. Qhov kev soj ntsuam no qhia tau hais tias tus cwj pwm hydration / dehydration ntawm HEC qauv feem ntau yog tswj hwm los ntawm lawv cov pab pawg hloov. Tus nqi nH ntawm HEC qauv yog qhov tseeb loj dua qhov tsawg kawg nkaus tseem ceeb nH tus nqi ntawm kwv yees li. 5 Cellulose ethers xws li MC thiab HpMC yuav tsum tau yaj rau hauv dej, txawm tias nyob rau hauv qhov kub siab. Txawm li cas los xij, HEC molecules yog dej-soluble hla ntau qhov kub thiab txias. Qhov kub nyob ntawm nH ntawm HEC qauv thiab triglycol (qauv sib xyaw ntawm HEC substituents) yog me me thiab lawv zoo sib xws rau ib leeg.
Qhov kev soj ntsuam no qhia tau hais tias tus cwj pwm hydration / dehydration ntawm HEC cov qauv feem ntau yog tswj hwm los ntawm lawv cov pab pawg hloov. HEC molecules yog dej-soluble hla ntau qhov kub thiab txias. Qhov kub nyob ntawm nH ntawm HEC cov qauv thiab triglycol (qauv sib xyaw ntawm HEC substituents) yog me me thiab lawv zoo sib xws. Qhov kev soj ntsuam no qhia tau hais tias tus cwj pwm hydration / dehydration ntawm HEC cov qauv feem ntau yog tswj hwm los ntawm lawv cov pab pawg hloov.HECCov molecule yog dej-soluble hla ntau qhov kub thiab txias. Qhov kub nyob ntawm nH ntawm HEC cov qauv thiab triglycol (qauv sib xyaw ntawm HEC substituents) yog me me thiab lawv zoo sib xws. Qhov kev soj ntsuam no qhia tau hais tias tus cwj pwm hydration / dehydration ntawm HEC cov qauv feem ntau yog tswj hwm los ntawm lawv cov pab pawg hloov pauv.
Lub sijhawm tshaj tawm: Plaub Hlis-25-2024