Daim ntawv thov ntawm polyether- hloov silicone roj hauv polyurethane ua npuas ncauj stabilizers
Polyether- hloov silicone roj, ib qho tseem ceeb additive nyob rau hauv polyurethane ua npuas ncauj cov ntaub ntawv, feem ntau ua hauj lwm raws li ib tug stabilizer thiab tseem hu ua ua npuas ncauj leveler. Txawm hais tias nws qhov ntau npaum li cas hauv cov qauv me me, feem ntau 0.5% rau 2.0% ntawm polyol, nws lub luag haujlwm tseem ceeb heev.
Plaub lub luag haujlwm tseem ceeb ntawm polyether- hloov silicone roj hauv polyurethane ua npuas ncauj yog:
Emulsifying nyhuv:
Nyob rau hauv thawj theem ntawm kev sib xyaw polyether polyol thiab isocyanate, vim lawv tsis zoo miscibility, pawg hydrophobic ntawm polyether- hloov silicone roj yog miscible nrog cov isocyanate, thaum cov pab pawg hydrophilic miscible nrog polyether polyol. Yog li ntawd, nws muaj peev xwm txhawb kev sib tov thiab emulsification ntawm ob, kom ntseeg tau tias cov tshuaj tiv thaiv pib uniformly nyob rau hauv lub system.
Txhim kho Bubble Generation thiab Homogenization:
Polyether- hloov cov roj silicone txo qhov nro ntawm cov tshuaj tiv thaiv kab mob, tso cai rau huab cua kom tawg mus rau hauv cov npuas zoo, tsim cov npuas nuclei. Qhov no muab tej yam kev mob rau cov gases generated los ntawm cov pa roj carbon dioxide thiab lub tshuab tshuab kom nkag mus rau hauv lub npuas nuclei thiab tsim npuas, thaum uas tsis muaj deg nro yog conducive rau npuas loj hlob.
Txhim kho Bubble Stabilization:
Nyob rau hauv qis system viscosity, cov tsim npuas nucleus kua zaj duab xis yog nyias thiab yooj yim ruptured vim kua, coalescence, los yog txhua yam cuam tshuam. Polyether-hloov silicone roj txhim khu kev ruaj ntseg ntawm npuas nuclei los ntawm Gibbs-Marangoni nyhuv, txo cov dej ntws tawm ntawm phab ntsa npuas thiab npuas coalescence. Tsis tas li ntawd, nws cov khoom tsis muaj zog pab txo qis van der Waals rog ntawm cov pa roj -kua interface, ntxiv stabilizing npuas.
Txhim kho Bubble Connectivity:
Nyob rau hauv lub kawg tsim theem ntawm polyurethane saj zawg zog ua npuas ncauj ntaub ntawv, npuas nucleus connectivity yog tseem ceeb heev. Nyob rau hauv qis system viscosity, polyether- hloov silicone roj pab txhawb kev ruaj ntseg ntawm lub npuas nucleus phab ntsa zaj duab xis thiab txhawb cov yeeb yaj kiab kom ncav cuag qhov qhib tseem ceeb - cell thickness, tsim cov xwm txheej rau qhov kawg qhib ntawm npuas nuclei.
Lub luag hauj lwm thiab ntau npaum ntawm Polyether -Modified Silicone Roj
Polyether-hloov silicone roj ua lub luag haujlwm ntawm lub stabilizer nyob rau hauv ib qho - kauj ruam tsim cov polyurethane hloov tau ua npuas ncauj.
Nws qhov ntau npaum li cas yuav tsum tau txiav txim siab los ntawm kev txiav txim siab zoo xws li cov txheej txheem foaming, formulation, foaming loj, thiab qhov loj ntawm cov khoom siv foaming. Feem ntau, qhov ntau npaum li cas yog 0.5 txog 2.5 feem polyether- hloov silicone roj ib 100 feem ntawm polyether polyol. Insufficient dosage may lead to small foam volume, high density, large bubble diameter, cracks and voids inside and on the surface of the foam, and even foam collapse. Kev sib ntxiv ntau dhau tsis yog tsuas yog siv tsis tau xwb tab sis kuj tseem tuaj yeem txo cov npuas dej ua haujlwm.
