Tlhaloso ea mocheso oa phetoho ea khalase
Glass-Transition Temperature(Tg), ke mocheso oo polima e fetohang ho ona ho tloha boemong bo otlolohileng ho ea boemong ba khalase,E bolela mocheso oa phetoho oa polymer ea amorphous (ho kenyeletsoa karolo e seng ea kristale polimang ea kristale) ho tloha boemong ba khalase. ho ya boemong bo sisinyehang haholo kapa ho tloha morao ho ya pele.Ke mocheso o tlase ka ho fetisisa oo likarolo tsa macromolecular tsa li-polymer tsa amorphous li ka tsamaeang ka bolokolohi.Hangata e Emeloa ke Tg.E fapana ho latela mokhoa oa ho lekanya le maemo.
Ena ke pontšo ea bohlokoa ea ts'ebetso ea li-polymers.Ka holim'a mocheso ona, polymer e bontša elasticity;ka tlas'a mocheso ona, polima e bontša brittleness.E tlameha ho nahanoa ha e sebelisoa e le polasetiki, rabara, likhoele tsa maiketsetso, joalo-joalo Ka mohlala, mocheso oa phetoho ea khalase ea polyvinyl chloride ke 80 ° C.Leha ho le joalo, ha se moeli o ka holimo oa mocheso o sebetsang oa sehlahisoa.Ka mohlala, mocheso o sebetsang oa rabara o tlameha ho ba ka holim'a mocheso oa phetoho ea khalase, ho seng joalo o tla lahleheloa ke elasticity e phahameng.
Hobane mofuta oa polymer o ntse o boloka tlhaho ea oona, emulsion e boetse e na le mocheso oa phetoho ea khalase, e leng pontšo ea ho thatafala ha filimi ea ho roala e entsoeng ke emulsion ea polymer.Emulsion e nang le mocheso o phahameng oa phetoho ea khalase e na le seaparo se nang le boima bo phahameng, botlolo bo phahameng, ho hanyetsa matheba a matle, 'me ha ho bonolo ho silafatsa,' me thepa ea eona e meng ea mechine e ntle ka tsela e tšoanang.Leha ho le joalo, mocheso oa phetoho ea khalase le mocheso oa eona o fokolang oa ho etsa filimi le tsona li phahame, e leng se tlisang mathata a itseng ho sebelisoa ha mocheso o tlaase.Sena ke ho hanyetsana, 'me ha emulsion ea polymer e fihla mocheso o itseng oa phetoho ea khalase, boholo ba thepa ea eona e tla fetoha ea bohlokoa, kahoo mocheso o nepahetseng oa phetoho ea khalase o tlameha ho laoloa.Mabapi le seretse se fetotsoeng ka polymer, ha mocheso oa phetoho ea khalase o phahame, matla a hatellang a seretse se fetotsoeng a phahame.Ha mocheso oa phetoho ea khalase o le tlase, ho ba molemo ho sebetsa ha mocheso o tlase oa seretse se fetotsoeng.
Tlhaloso e fokolang ea mocheso oa filimi e etsang filimi
Mocheso o fokolang oa ho etsa lifilimi ke oa bohlokoasesupo sa seretse se omileng se kopaneng
MFFT e bua ka mocheso bonyane oo likaroloana polymer ka emulsion na le motsamao lekaneng ho agglomerate le mong ho e mong ho theha filimi e tsoelang pele.Ts'ebetsong ea emulsion ea polymer e etsang filimi e sa khaotseng ea ho roala, likaroloana tsa polymer li tlameha ho theha tlhophiso e haufi-ufi.Ka hona, ntle le ho qhalakanngoa ho hotle ha emulsion, maemo a ho etsa filimi e tsoelang pele a boetse a kenyelletsa deformation ea likaroloana tsa polymer.Ke hore, ha khatello ea capillary ea metsi e hlahisa khatello e kholo pakeng tsa likaroloana tsa spherical, ha likaroloana tsa spherical li ntse li hlophisitsoe, khatello e eketseha haholo.
Ha likaroloana li kopana, khatello e hlahisoang ke ho fetoha ha metsi ho qobella likaroloana ho hatelloa le ho holofala hore li tlamahane ho etsa filimi ea ho roala.Ho hlakile hore bakeng sa li-emulsion tse nang le li-agent tse batlang li le thata, boholo ba likaroloana tsa polymer ke li-resin tsa thermoplastic, ha mocheso o le tlase, ho thatafala le ho thata ho feta ho holofala, kahoo ho na le bothata ba mocheso o fokolang oa ho etsa filimi.Ke hore, ka tlas'a mocheso o itseng, ka mor'a hore metsi a emulsion a fetohe mouoane, likaroloana tsa polymer li ntse li le boemong bo fapaneng 'me li ke ke tsa kopanngoa.Ka hona, emulsion e ke ke ea etsa seaparo se sa khaotseng sa junifomo ka lebaka la ho fetoha mouoane ha metsi;'me Ka holim'a mocheso ona o khethehileng, ha metsi a fetoha mouoane, limolek'hule tse karolong e 'ngoe le e' ngoe ea polymer li tla phunyeletsa, li hasane, li senyehe, 'me li kopane ho etsa filimi e hlakileng e tsoelang pele.Moeli ona o tlase oa mocheso oo filimi e ka thehoang ho oona o bitsoa bonyane mocheso oa ho etsa filimi.
MFFT ke sesupo sa bohlokoa saemulsion ea polymer, 'me ke habohlokoa ka ho khetheha ho sebelisa emulsion nakong ea mocheso o tlaase.Ho nka mehato e nepahetseng ho ka etsa hore emulsion ea polymer e be le mocheso o fokolang oa ho etsa filimi o finyellang litlhoko tsa tšebeliso.Ka mohlala, ho eketsa polasetiki ho emulsion ho ka nolofatsa polymer le ho fokotsa haholo mocheso o fokolang oa ho etsa filimi ea emulsion, kapa ho fetola mocheso o fokolang oa ho etsa filimi.Li-emulsions tse phahameng tsa polymer li sebelisa li-additives, joalo-joalo.
MFFT ea LongouVAE phofo e ka sebelisoang hape ea latexhangata e pakeng tsa 0°C le 10°C, e tloaelehileng haholo ke 5°C.Ka mocheso ona, hophofo ea polymere hlahisa filimi e tsoelang pele.Ho e-na le hoo, ka tlas'a mocheso ona, filimi ea redispersible polymer powder ha e sa tsoela pele ebile e senya.Ka hona, mocheso o fokolang oa ho etsa filimi ke pontšo e emelang mocheso oa kaho oa morero.Ha re bua ka kakaretso, ha mocheso o tlase o tlase oa ho etsa filimi, ho na le bokhoni ba ho sebetsa hantle.
Phapano lipakeng tsa Tg le MFFT
1. Mocheso oa phetoho ea khalase, mocheso oo ntho e bonolo.Haholo-holo e bua ka mocheso oo li-polymer tsa amorphous li qalang ho ba bonolo.Ha e amane feela le sebopeho sa polymer, empa hape le boima ba eona ba molek'hule.
2.Ntho e bonolo
Ho ea ka matla a fapaneng a ho sisinyeha a li-polymers, boholo ba lisebelisoa tsa polima hangata li ka ba maemong a mane a latelang a 'mele (kapa maemo a mochini): boemo ba khalase, boemo ba viscoelastic, boemo bo otlolohileng haholo (boemo ba rabara) le boemo ba phallo ea viscous.Phetoho ea khalase ke phetoho pakeng tsa boemo bo tsitsitseng haholo le boemo ba khalase.Ho latela pono ea sebopeho sa limolek'hule, mocheso oa phetoho ea khalase ke ntho e khathollang ea karolo ea amorphous ea polymer ho tloha sebakeng se leqhoa ho ea sebakeng se qhibilihileng, ho fapana le mohato.Ho na le mocheso oa phetoho ea mohato nakong ea phetoho, kahoo ke phetoho ea karolo ea bobeli (e bitsoang phetoho ea mantlha ho mechanics ea polymer dynamic).Ka tlas'a mocheso oa phetoho ea khalase, polymer e boemong ba khalase, 'me liketane tsa limolek'hule le likarolo ha li khone ho sisinyeha.Ke liathomo feela (kapa lihlopha) tse etsang limolek'hule tse thothomelang moo li leng teng;ha e ntse e le mocheso oa phetoho ea khalase, le hoja liketane tsa limolek'hule E ke ke ea sisinyeha, empa likarolo tsa ketane li qala ho tsamaea, li bontša thepa e phahameng ea elastic.Haeba mocheso o eketseha hape, ketane eohle ea molek'hule e tla tsamaea 'me e bontše thepa ea ho phalla ha viscous.Mocheso oa phetoho ea khalase (Tg) ke thepa ea bohlokoa ea 'mele ea li-polymers tsa amorphous.
Mocheso oa phetoho ea khalase ke e 'ngoe ea lithempereichara tse ikhethang tsa li-polymers.Ho nka mocheso oa phetoho ea khalase e le moeli, li-polymers li bontša litšobotsi tse fapaneng tsa 'mele: ka tlas'a mocheso oa phetoho ea khalase, thepa ea polymer ke polasetiki;ka holim'a mocheso oa phetoho ea khalase, thepa ea polymer ke rabara.Ho latela pono ea lits'ebetso tsa boenjiniere, moeli o kaholimo oa ts'ebeliso ea mocheso oa mocheso oa mocheso oa likhalase tsa polasetiki ke moeli o tlase oa ts'ebeliso ea rabara kapa li-elastomers.
Nako ea poso: Jan-04-2024