Kev soj ntsuam microscopic
Cov polylactic acid fibers tau pom los ntawm microscope. Tus ntoo khaub lig ntawm polylactic acid fibers yog kwv yees li ncig, thiab lub longitudinal seem fibers tau du thiab pom.
Polylactic acid fiber ntau hla ntu
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Kev kuaj combustion
Fibers yaj thiab ntsws thaum lawv nyob ze ntawm cov nplaim taws; Fibers yaj thiab hlawv thaum lawv tiv cov nplaim taws; Thaum tawm hauv cov nplaim taws, cov fibers melts thiab hlawv, thiab yaj poob. Cov fibers hlawv nrog me ntsis tshwj xeeb qab zib saj; Cov residue yog daj ntseg daj jelly. Raws li txoj kev kuaj combustion, cov yam ntxwv ntawm polylactic acid fiber ntau zoo ib yam li cov hluavtaws fiber ntau, thiab tsis muaj qhov tshwm sim tshwj xeeb. Txawm li cas los xij, polylactic acid fiber ntau hlawv nrog lub pob tshab pob tshab nplaim taws thaum nws tawm ntawm cov nplaim taws, thiab nws cov residue yog ib qho me me ntawm cov pos hniav daj, uas txawv ntawm polyester fiber. Txawm li cas los xij, qhov tshwm sim ntawm tus cwj pwm no tsis pom tseeb tias nws tsis tuaj yeem lees paub tias yog polylactic acid fiber ntau los ntawm txoj kev no ib leeg.
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Melting point test
Polylactic acid fiber yog yaj ntawm li 150 degree thiab tag nrho yaj ntawm 165 degree ~ 170 degree. Nyob rau hauv txoj kev melting point, lub melting point ntawm polylactic acid fiber yog nyob nruab nrab ntawm 165 degree ~ 170 degree, lub melting point ntawm polyester fiber feem ntau yog hais txog 252 degree, nylon 6 fiber yog hais txog 220 degree, nylon 66 yog hais txog 260 degree, polypropylene fiber. yog hais txog 180 degree, ethylene fiber ntau yog li 160 degree, txawm hais tias nws tuaj yeem txawv ntawm polyester thiab nylon, tab sis yooj yim rau confuse nrog ethylene fiber, Nrog rau kev loj hlob ntawm ntau yam tsawg melting point polyester, nws tsis yooj yim rau siv melting point txoj kev. Kev txheeb xyuas qhov zoo.
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Infrared spectrum
Lub infrared absorption spectrum ntawm polylactic acid tau soj ntsuam
Nws tuaj yeem pom los ntawm infrared absorption spectrum uas muaj lub zog nqus siab kawg ntawm ob daim ntawv cog lus ncab kev co ntawm li 1747cm-1, CO stretching vibration ntawm txog 1076cm-1, thiab muaj ob lub zog nqus siab tshaj plaws ntawm txog 1179cm-1, qhia tias cov fiber ntau muaj ester cov yam ntxwv ntawm kev nqus peaks, belongs rau tsev neeg polyester. Tab sis C=O stretching vibration zaus txoj hauj lwm sib xws rau benzene nplhaib conjugated polyester chav kawm kom siab, lub zog yuav tsis muaj zog.
Hauv kev ntsuas infrared nqus spectrum, daim ntawv qhia spectral absorption ntawm polylactic acid fiber thiab polyester fiber muaj qhov zoo sib xws, tab sis cov yam ntxwv ncov ntawm polylactic acid: 1076cm-1, 1179cm-1, 1747cm-1 , qhia tias cov fiber ntau muaj ester yam ntxwv ntawm lub siab nqus, teej tug mus rau tsev neeg polyester. Raws li lub conjugation ntawm C=O pab pawg thiab benzene nplhaib, lub stretching vibration zaus ntawm C=O pab pawg yog siab tshaj qhov saum toj no txoj hauj lwm, thiab lub zog yog muaj zog los yog tsis muaj zog, polylactic acid fiber thiab polyester fiber ntau tuaj yeem paub qhov txawv.
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Tshuaj tua kab mob
Kev ntsuas tshuaj lom neeg ntawm polylactic acid fiber ntau tau ua los soj ntsuam lub xeev kev puas tsuaj ntawm polylactic acid fiber hauv qee cov kua qaub, alkali, ntsev thiab cov kuab tshuaj organic nyob rau hauv qee yam kev mob ntawm qhov kub thiab txias thiab lub sijhawm so. Yog xav paub ntxiv, saib Table 1.
Lus Cim: S 0 -- yaj tam sim ntawd, S -- yaj, P -- ib nrab yaj, Kuv -- insoluble, △ -- o.
Nyob rau hauv txoj kev xeem dissolution, nws tuaj yeem pom los ntawm cov lus saum toj no tias polylactic acid fiber ntau tuaj yeem yaj hauv dichloromethane thiab boiled dimethylformamide ntawm qhov kub thiab txias, uas tuaj yeem paub qhov txawv ntawm polyester, uas yog lub ntsiab lus tseem ceeb los txheeb xyuas polylactic acid fiber thiab polyester fiber. , polypropylene fiber ntau thiab ethylene fiber. Cov tshuaj solubility ntawm polylactic acid fiber yog tib yam li polyester fiber, tab sis polylactic acid fiber belongs rau linear fatty tsev neeg polyester fiber, thaum polyester belongs rau aromatic tsev neeg polyester fiber. Qhov sib txawv ntawm cov qauv molecular ntawm ob fibers no ua rau pom tseeb qhov sib txawv ntawm cov tshuaj solubility.