Kev tsim cov tshuaj polyols rau cov ntawv thov cov khoom noj
Polyols uas siv rau hauv cov ntawv thov cov zaub mov muaj feem ntau los ntawm hydrogenation ntawm cov suab thaj lossis cov hmoov txhuv nplej siab. Cov txheej txheem no cuam tshuam nrog cov qab zib los yog cov hmoov txhuv nplej siab nrog cov roj kub ntawm cov tshuaj tua hluav taws kub siab thiab muaj ib qho hlau hlau zoo li Nickel lossis Palladium.
Thaum lub sij hawm hydrogenation, ob txoj hlua khi nyob hauv cov piam thaj lwg me me yog cov athal nrog hydrogen atoms, ua rau polyols los ua.
Tom qab cov tshuaj tiv thaiv, cov polyols yog huv los ntawm distillation lossis crystallization kom ua tiav cov khoom lag luam siab.
Kev tsim cov polyether polyols rau polyurethane ua npuas ncauj thiab lwm yam kev siv
Polyols siv nyob rau hauv polyurethane ua npuas ncauj thiab lwm cov ntawv thov uas tsis yog cov khoom siv-cov khoom siv ntsig txog cov khoom siv los ntawm polymerization ntawm alkylene oxides. Hauv hom no, txawm tias antylene oxide (po) los yog ethylene oxide (xws li muaj cov pa ntxig oms, xws li glycerol lossis dipropylene glycol.
Cov tshuaj tiv thaiv no siv nyob rau hauv lub xub ntiag ntawm catalyst, feem ntau yog cov poov tshuaj hydroassst zoo li cov poov tshuaj hydrocksium, uas ua kom yooj yim ntawm cov oxide rau statter molecule. Qhov tshwm sim yog qhov tsim ntawm polyols nrog ntau cov hydroxyl (OH) pawg. Cov polyols pab ua polymeric caj qaum rau polyurethane ua npuas ntau lawm. Isocyanates, nrog rau cov khoom ntxiv ntxiv xws li tshuab cov neeg sawv cev thiab cov catalysts, yog tom qab ntawd tov nrog cov polyols los tsim cov npuas dej.
Finnetuning Polyols rau Kev Ua Haujlwm
Kho cov molecular hnyav ntawm ib polyol tuaj yeem hloov nws cov yam ntxwv thiab, vim tias, hloov pauv seb nws ua li cas hauv daim ntawv thov. Piv txwv li, cov ua npuas ncauj hauv lub cim ua npuas ncauj yog ua los ntawm kev sib xyaw ntawm polyols nrog hnyav dua thiab qis dua molecular hnyav dua li ib lub txaj pw. Qhov hnyav molecular tuaj yeem cuam tshuam kev siv taus, lossis ntev npaum li cas nws yuav siv lub txaj kom rov qab tom qab koj nias koj txhais tes mus rau hauv npuas dej.
Kho cov pa roj teeb hauv polyols kuj tuaj yeem hloov pauv kev ua tau zoo. Piv txwv li, qee cov polyols ua nrog cov roj carbon uas ntes tau ntawm cov pob zeb fossil-raws cov pa roj carbon monoxide.
Koj tuaj yeem pom cov dab neeg zoo sib xws hauv lwm cov kev thov thiab kev faib cov roj ntsha ua rau cov viscosity, ntws ntawm cov khoom siv, thiab cov yeeb yaj kiab tuab. Ib qho ntxiv, hloov cov qauv siv tshuaj ntawm polyols los ntawm kev sib xyaw ua cov pab pawg ua haujlwm xws li cov carboxyl, lossis epoxy pawg tuaj yeem txhim kho cov nplaum, cov kab ke ntawm cov txheej.