Polyether Polyols
Ob tsev neeg loj ntawm polyether polyols yog polytetramethylene ether glycols (PTMEG) thiab polypropylene glycols (PPG).
PTMEG yog thawj polyol siv nyob rau hauv high-performance polyurethane elastomers. PTMEG-raws li polyurethanes muaj kev tiv thaiv zoo tshaj plaws rau hydrolytic cleavage, zoo mechanical zog tuav ntawm qhov kub thiab txias, siab resiliency, zoo ua cov yam ntxwv, thiab zoo heev mechanical thiab dynamic zog. Strain-induced crystallization ntawm PTMEG mos ntu, kev ua haujlwm tsis zoo, thiab cov kua qaub qis yog txhua yam ua rau muaj txiaj ntsig zoo ntawm cov khoom siv polyurethane elastomers.
PPG polyols muaj cov tshuaj hydrolysis zoo heev thiab tsis muaj qhov kub thiab txias. Txawm li cas los xij, thaum piv rau PTMEG polyols, PPG polyols muaj cov khoom siv tsis zoo thiab muaj ntau dua rau cov thermo-oxidative degradation.
Nyob rau hauv lub xeev ua kua ntawm chav tsev kub, PPG polyols ua ib qho kev xaiv zoo heev rau chav tsev kub.
Polyethers muaj qhov kub hloov pauv iav qis (Tg), uas ua rau muaj kev tuav pov hwm zoo ntawm lub cev thiab cuam tshuam rau qhov kub thiab txias. Lawv yog cov kev xaiv tsim nyog rau cov ntawv thov uas qhov chaw urethane yuav tsum ua nyob rau hauv qhov chaw txias heev.
Txawm hais tias polyether polyols muaj kev ruaj ntseg hydrolytic zoo heev, lawv muaj kev tiv thaiv tsis zoo rau cov uas tsis yog-polar, hydrocarbon-raws li cov kuab tshuaj thiab yuav tsum tsis txhob siv rau hauv cov ntawv thov uas cov khoom yuav raug rau cov roj ntxhia. Nyob rau hauv cov cheeb tsam no, lawv cov khoom yuav deteriorate sai sai.
PTMEG-raws li urethanes yog cov khoom xaiv rau cov ntawv thov uas cov khoom hauv qab no tseem ceeb:
Zoo impingement abrasion (siab resiliency)
Hydrolytic stability nyob rau hauv cov av ntub / ntub dej
Cov khoom zoo dynamic (log, rollers, yob npog)
Kev siv kub tsawg
Tsis tas li ntawd, PTMEGs muaj cov viscosities tsawg, ua rau lawv yooj yim rau kev ua thiab ua tiav kev sib xyaw zoo.