Thermoplastic polyurethane (TPU) yog hom polyurethane uas tuaj yeem muab cov yas ua kom sov thiab yaj los ntawm cov kuab tshuaj. Piv nrog myurethane thiab cam khwb cia polyurethane, TPU muaj tsawg rau tsis muaj tshuaj lom neeg cov qauv tshuaj, thiab nws cov molecular charets yog qhov tseem ceeb tawm. Txawm li cas los xij, nws muaj qee tus naj npawb ntawm cov ntoo khaub lig lub cev.
The concept of physical crosslinking was first proposed by Schollenberger CS in 1958. It refers to the reversible "connection points" that exist between linear polyurethane molecular chains when exposed to heat or solvents. Cov ntsiab lus no tsis yog tshuaj hla kev suav, tab sis lawv ua zoo li lawv. Ua tsaug rau cov ntsiab lus ntawm lub cev, polyurethane ua cov morphology ntau. Lub hydrogen bonds nyob rau hauv polyurethane txhawb nqa cov qauv no thiab txhim kho nws txoj kev tiv thaiv kom av noo.
Dab tsi yog cov kev faib tawm ntawm polyurethane tpu?
Txij li tam sim no peb paub dab tsi thermoplastic polyurethane yog, cia saib nws cov kev faib tawm. Nyob ntawm cov txheej txheem sib txawv, TPU tuaj yeem muab faib ua ntau pawg.
Piv txwv li:
Raws li cov qauv Segment Segment, TPU tuaj yeem faib rau hauv polyester-raws, muaj cov pab pawg polybutadiene, thiab cov pab pawg ntawm Esther, lossis pawg neeg sab nrauv, feem ntau.
Raws li cov qauv segment nyuaj, muaj hom polyurethane thiab polyurethane-urea hom, tsim nrog diol lossis cov sib zog sib luag.
Feem ntau ntawm kev faib tawm yog polyester-based thiab polyether-based tpu.
Ntxiv kev faib tawm muaj xws li:
Raws li crosslinking: purely thermoplastic (linear, tsis muaj crosslinks) thiab semi-thermopinast (nrog me crosslinks xws li urethane-urethans-devere).
Raws li kev siv Xaus: Cheebtsam kev cai (ntau yam tubing (sheath
Yuav ua li cas yog polyurethane tpu synthesized?
Txawm hais tias TPU los ntawm ntau pawg, lawv txhua tus poob rau hauv tsev neeg polyurethane ntawm cov qib molecular. Yog li cas yog li cas tpu synthesized?
Raws li cov txheej txheem sib txawv, TPU yog feem ntau tsim los ntawm kev ua haujlwm polymerization lossis daws teeb meem.
Hauv cov polymerization, muaj ob txoj kev tseem ceeb:
Npaj ua ntej: Diisocyanates rov qab nrog macrodiols ua ntej, tom qab los ntawm kev ntxiv ntawm cov saw txuas ntxiv los tsim tpu.
Ib-leeg-tua txoj kev: Macrodiols, Diisocyanates, thiab saw txuas yog txhua qhov sib xyaw thiab siv tau ib txhij los ua TPU.
Hauv kev daws teeb meem polymerization, Diisocyanates yog thawj zaug yaj nyob rau hauv ib lub kuab tshuaj, thiab thaum kawg cov saw txuas tau ua rau muaj TPU.
Hom kev muag muag muag, cov ntsiab lus hnyav, cov ntsiab lus ntawm lub xeev nyuaj lossis cov kev sib cav sib ceg Ntawm tib lub hardness, polyether-based tpu feem ntau muaj qhov qis dua li polyester-based tpu.
Panyurethane Tpu ua tiav li cas?
Thaum synthesized, Tpu Pellets yuav tsum tau ua tiav rau hauv cov khoom lag luam kawg uas siv ntau txoj kev siv ntau txoj kev, feem ntau cov kev ua tiav thiab kev ua haujlwm.
Cov txheej txheem melting siv cov txheej txheem ua tiav cov yas xws li kev txhaj tshuaj moulding, compression, hloov moulding, hloov moulding, thiab centrifugal moulding).
Kev ua cov tshuaj cuam tshuam nrog cov pellots hauv cov kuab tshuaj lossis polymerizing ncaj qha rau cov kev daws teeb meem, uas yog tom qab ntawd siv rau txheej, kiv, thiab lwm yam txheej txheem.
Elastomeric TPU feem ntau tsis tas yuav vulcanization, uas shotens ntau lawm cycles thiab tso cai rau kev rov ua dua cov khoom siv pov tseg.