Dab tsi yog sponge ua npuas ncauj ua los ntawm

Daim txhuam cev yog ib hom polyurethane ua npuas ncauj uas belongs rau saj zawg zog polyurethane ua npuas ncauj. Vim hais tias ntawm cov qauv ntxeem tau honeycomb, nws muaj cov yam ntxwv ntawm softness, elasticity, nqus dej thiab dej tsis kam, thiab yog dav siv nyob rau hauv sofas, txaj, khaub ncaws, saj zawg zog ntim thiab lwm yam lag luam.

1. Cov khoom siv tseem ceeb

1.1 Polyether polyol

Sponges feem ntau siv polyether propylene glycol thiab polyether glycerol, uas muaj kev ua haujlwm tsawg dua (2-3), qis hydroxyl tus nqi thiab qhov hnyav molecular loj. Cov mis mos molecular yog:

1.2 Organic isocyanates

Feem ntau siv yog methylbenzene diisocyanate, hu ua TDI, muaj ob isomers, namely 2, 4-TDI, 2, 6-TDI. Hauv kev tsim cov sponge 2,4-TDI suav rau 80 feem pua, 2,6-TDI 20 feem pua

1.3 Dej

Hauv kev tsim cov sponges, dej yog indispensable. Dej reacts nrog TDI kom tso CO2 roj, uas kuj plays lub luag hauj lwm nyob rau hauv txoj kev loj hlob ntawm saw.

1.4 Catalyst

Cov catalysts uas txhawb cov tshuaj tiv thaiv ntawm polyether polyol nrog isocyanate kom cov saw yog stannous octoate thiab dibutyltin. Cov catalysts uas txhawb kev sib txuas lus sib txuas thiab tuaj yeem txhawb nqa CO2 roj tso tawm los ntawm cov tshuaj tiv thaiv ntawm isocyanate thiab dej suav nrog triethanolamine, triethylenediamine, triethylamine, thiab lwm yam.

1.5 External foaming agent

Feem ntau siv yog cov tshuaj fluorocarbon uas tsis tshua muaj boiling, xws li monofluorotrichloromethane (F-11). Txij li nws tsis yog ib puag ncig tus phooj ywg, cyclopentane feem ntau yog siv los hloov F-11, lossis dichloromethane, thiab cov nyhuv zoo. Yog tias nws tsis yog rau kev tsim khoom ntawm ultra-lub teeb extra-lub teeb raw kuj tseem tuaj yeem hloov kho kom tsim nyog, thiab cov chaw ua npuas ncauj sab nraud tsis siv.

1.6 Ua npuas ncauj stabilizer

(Foam stabilizer) Silicone ua npuas ncauj stabilizer feem ntau yog siv. Tam sim no, silicon-carbon bond Si-C copolymer feem ntau yog siv, thiab qhov ntau npaum li cas yog 0.5 feem pua ​​-5 feem pua.

2. Lub hauv paus ntsiab lus synthesis ntawm daim txhuam cev

Nyob rau hauv cov txheej txheem synthesis ntawm daim txhuam cev, feem ntau yog cov saw kev loj hlob, foaming thiab cross-linking, thiab lwm yam. Cov tshuaj tiv thaiv no muaj feem xyuam rau cov qauv molecular, functionality, thiab molecular hnyav ntawm raw cov ntaub ntawv.

2.1 Chain extension cov tshuaj tiv thaiv

Isocyanate thiab ua haujlwm tsis zoo ntawm polyether polyol saw txuas ntxiv cov tshuaj tiv thaiv, vim tias cov isocyanate ntau dhau hauv cov tshuaj tiv thaiv yog li 5 feem pua, yog li cov khoom kawg ntawm cov saw txuas ntxiv yog isocyanate pawg, uas yog pheej rov ua kom cov saw hlau loj hlob sai.

2.2 Cov tshuaj tiv thaiv foaming yog nrog los ntawm kev loj hlob ntawm cov saw hlau

Nyob rau hauv cov txheej txheem ntawm kev tsim cov sponge, cov roj foaming feem ntau yog los ntawm cov tshuaj tiv thaiv ntawm TDI thiab dej los tsim cov pa roj CO2 ntau, thiab tib lub sijhawm, cov amine tsim tawm tshiab reacts nrog cov isocyanate los tsim cov urea bond compound, uas yog rov qab nrog kev loj hlob ntawm cov saw hlau.

2.3 Cross-linking reaction

Cov tshuaj tiv thaiv kev sib txuas yog qhov tseem ceeb heev rau kev npaj daim txhuam cev. Yog tias nws tshwm sim ntxov dhau los yog lig dhau lawm, qhov zoo ntawm daim txhuam cev yuav txo qis lossis txawm tias yuav raug muab pov tseg.

2.3.1 Crosslinking ntawm multifunctional compounds

Cov tshuaj tiv thaiv ntawm polyether polyol thiab isocyanate ncaj qha cuam tshuam rau qhov ntom ntawm daim txhuam cev. Qhov hnyav molecular ntawm qhov crosslinking point yog 2000-20000. Qhov me me qhov hnyav molecular, ntau dua qhov crosslinking ceev, siab dua qhov hardness ntawm npuas, thiab cov txheeb ze txo qis hauv softness thiab elasticity.

2.3.2 Biuret Crosslinking

Dej reacts nrog isocyanate los tsim cov urea bond compound, uas ntxiv reacts nrog isocyanate los ua ib qho tri-directional biuret cross-linking compound.

2.3.3 Allophanate Crosslinking

Cov hydrogen ntawm nitrogen atom hauv pawg urethane reacts nrog cov isocyanate los ua ib qho allophanate nrog peb txoj kev sib txuas.

3. Daim txhuam cev ntau lawm tshuab thiab txheej txheem

Tam sim no, feem ntau ntawm daim txhuam cev ntau lawm txais cov txheej txheem ib-kauj ruam ua npuas ncauj. Ntau yam khoom siv raw tau ntxiv sai sai rau hauv lub thawv tsim nyob rau hauv high-speed stirring, thiab cov saw loj hlob, foaming, cross-linking, curing thiab lwm yam kev cuam tshuam yog ua tiav nyob rau hauv lub thawv tsim, thiaj li ua kom tiav daim txhuam cev. Ntau lawm. Qhov zoo ntawm cov txheej txheem no yog cov txheej txheem luv luv, cov khoom siv viscosity tsawg, tswj tau yooj yim, txuag hluav taws xob, cov cuab yeej siv me me, thiab cov khoom siv dav dav.