Technical indicators, Aspolyacrylamideyog feem ntau molecular hnyav, hydrolysis degree, ionic degree, viscosity, residual monomer cov ntsiab lus, yog li txiav txim qhov zoo ntawm PAM kuj raug txiav txim los ntawm cov ntsuas no!
01Molecular Luj
Qhov hnyav molecular ntawm PAM yog siab heev thiab tau txhim kho zoo nyob rau hauv xyoo tas los no.PAM, uas tau siv rau xyoo 1970s, muaj qhov hnyav molecular ntawm lab. Txij li thaum xyoo 1980s, qhov hnyav molecular ntawm PAM ua tau zoo tshaj plaws yog ntau tshaj 15 lab, thiab qee qhov mus txog 20 lab. "Txhua ntawm cov PAM molecules no yog polymerized los ntawm ntau tshaj ib puas txhiab acrylamide los yog sodium acrylate molecules (acrylamide muaj ib tug molecular hnyav ntawm 71, thiab PAM nrog ib puas txhiab monomers muaj ib tug molecular hnyav ntawm 7.1 lab).
Feem ntau, PAM nrog qhov hnyav molecular muaj qhov ua tau zoo flocching, nrog rau qhov hnyav molecular ntawm 71 rau acrylamide thiab 7.1 lab rau PAM muaj 100,000 monomers. Qhov hnyav molecular ntawm polyacrylamide thiab nws cov derivatives los ntawm ntau pua txhiab mus rau ntau tshaj 10 lab, raws li qhov hnyav molecular yuav muab faib ua qhov hnyav molecular (qis dua 1 lab), nruab nrab molecular hnyav (1 lab mus rau 10 lab), siab molecular hnyav. (10 lab mus rau 15 lab), super molecular hnyav (ntau tshaj 15 lab).
Qhov hnyav molecular ntawm macromolecular organic teeb meem, txawm tias nyob rau hauv tib cov khoom tsis yog tag nrho, lub nominal molecular hnyav yog nws qhov nruab nrab.
02 ibDegree ntawm hydrolysis thiab degree ntawm ion
Lub ionic degree ntawm PAM muaj kev cuam tshuam zoo rau nws cov txiaj ntsig siv, tab sis nws qhov tsim nyog tus nqi nyob ntawm hom thiab qhov xwm txheej ntawm cov khoom kho, yuav muaj qhov sib txawv ntawm qhov zoo nyob rau hauv ntau qhov xwm txheej. Yog hais tias lub zog ionic ntawm cov khoom kho yog siab dua (muaj ntau cov tshuaj inorganic), ionic degree ntawm PAM yuav tsum siab dua, ntawm qhov tsis sib xws, nws yuav tsum qis dua. Feem ntau, cov degree ntawm anion yog hu ua degree ntawm hydrolysis. Thiab ionic degree feem ntau yog hais txog cations.
Ionicity = n / (m + n) * 100%
Lub PAM uas tsim nyob rau hauv thaum ntxov theem yog polymerized los ntawm ib tug monomer ntawm polyacrylamide, uas tsis muaj cov pab pawg neeg -COONa. Ua ntej siv, NaOH yuav tsum tau ntxiv thiab rhaub kom hydrolyze ib feem ntawm -CONH2 pawg rau -COONa. Qhov sib npaug yog raws li nram no:
-CONH2 + NaOH → -COONa + NH3↑
Cov roj ammonia tso tawm thaum lub sij hawm hydrolysis. Qhov kev faib ua feem ntawm amide pawg hydrolysis hauv PAM yog hu ua qib ntawm hydrolysis ntawm PAM, uas yog qib ntawm anion. Kev siv hom PAM no tsis yooj yim, thiab kev ua haujlwm tsis zoo (cov cua sov hydrolysis yuav ua rau qhov hnyav molecular thiab kev ua haujlwm ntawm PAM poob qis), tsis tshua siv txij li xyoo 1980s.
Kev tsim khoom niaj hnub ntawm PAM muaj ntau yam khoom sib txawv ntawm cov khoom lag luam anion, tus neeg siv tuaj yeem ua raws li qhov xav tau thiab los ntawm qhov kev sim tiag tiag los xaiv ntau yam tsim nyog, tsis tas yuav hydrolysis, tom qab kev sib cais tuaj yeem siv tau.Txawm li cas los xij, rau cov laj thawj ntawm tus cwj pwm, qee cov neeg tseem xa mus rau cov txheej txheem kev sib cais ntawm flocculants li hydrolysis. Nws yuav tsum tau muab sau tseg tias lub ntsiab lus ntawm hydrolysis yog decomposition ntawm dej, uas yog ib tug tshuaj tiv thaiv. Lub hydrolysis ntawm PAM muaj ammonia roj tso tawm; Kev puas tsuaj tsuas yog ua rau lub cev, tsis muaj tshuaj lom neeg. Qhov ob yog qhov sib txawv thiab yuav tsum tsis txhob totaub.
03Residual monomer cov ntsiab lus
Cov ntsiab lus monomer residual ntawm PAM hais txog cov ntsiab lus ntawmAcrylamide monomernyob rau hauv acrylamide polymerization rau hauv polyacrylamide nyob rau hauv tus txheej txheem ntawm tsis tiav cov tshuaj tiv thaiv thiab thaum kawg residual nyob rau hauv acrylamide cov khoom. Nws yog ib qho tseem ceeb parameter los ntsuas seb nws puas haum rau kev lag luam khoom noj. Polyacrylamide tsis muaj tshuaj lom, tab sis acrylamide muaj qee yam tshuaj lom. Hauv kev lag luam polyacrylamide, nws yog ib qho nyuaj kom tsis txhob muaj qhov seem ntawm unpolymerized acrylamide monomer. Yog li ntawd, cov ntsiab lus ntawm residual monomer nyob rau hauvPAM cov khoomyuav tsum tau tswj nruj heev. Tus nqi ntawm cov monomer residual hauv PAM siv hauv cov dej haus thiab kev lag luam zaub mov tsis pub tshaj 0.05% thoob ntiaj teb. Tus nqi ntawm cov khoom lag luam nto moo txawv teb chaws yog qis dua 0.03%.
04 ibviscosity
PAM daws yog nkig heev. Qhov siab dua qhov hnyav molecular ntawm PAM, qhov ntau dua qhov viscosity ntawm cov tshuaj. Qhov no yog vim PAM macromolecules ntev, nyias chains uas muaj kev tiv thaiv zoo los ntawm kev daws teeb meem. Lub ntsiab lus ntawm viscosity yog los cuam tshuam qhov loj ntawm kev sib txhuam quab yuam nyob rau hauv cov tshuaj, kuj hu ua internal kev sib txhuam coefficient. Lub viscosity ntawm kev daws ntawm txhua yam ntawm polymer organic teeb meem yog siab thiab nce nrog qhov nce ntawm molecular hnyav. Ib txoj hauv kev los txiav txim siab qhov hnyav molecular ntawm polymer organic teeb meem, yog txiav txim siab qhov viscosity ntawm qee qhov kev daws teeb meem nyob rau hauv qee yam mob, thiab tom qab ntawd raws li ib qho qauv los xam nws qhov hnyav molecular, hu ua "viscose nruab nrab molecular hnyav".
Post lub sij hawm: Jan-12-2023