Yintoni i-polyurethane?Ziziphi iingenelo kunye nokungalunganga kwezixhobo ze-polyurethane?

Ukususela ekuqaleni kwemveliso yezoshishino kwiminyaka ye-1950, izinto ze-polyurethane (oko kukuthi, iipolymers eziphezulu ze-molecular eziqukethe amaqela e-carbamate kwikhonkco eliphambili le-macromolecules - i-NHCOO) iphuhliswe ngokukhawuleza.Xa kuthelekiswa nezixhobo zerabha ye-polymer, ineempawu zayo ezizodwa.Ingasebenzisa amanani ahlukeneyo amaqela asebenzayo kunye neentlobo ezahlukeneyo zamaqela asebenzayo ngokweemfuno ezahlukeneyo zokusebenza, kwaye isebenzise iinkqubo ezahlukeneyo zokuvelisa ukuvelisa iimveliso ze-polyurethane kunye nokusebenza kunye neempawu ezahlukeneyo.

Kukwakho nemathiriyeli engekhoyo kudidi lwerabha, njengeeplastiki ezinogwebu, iimveliso zeplastiki ezomeleleyo, izinto zokwaleka, iintsinga zokwenziwa ezinokomelela kakhulu, ufele lokwenziwa, izinto zokuncamathelisa, njl.

Izinto zePolyurethane okwangoku zisetyenziswa ngokubanzi kwiinkalo ezahlukeneyo, umzekelo, kwishishini le-aerospace, iimveliso zayo ezinzima, iimveliso ezithambileyo kunye neemveliso zogwebu zikhaphukhaphu kunezixhobo zentsimbi (zibaluleke kakhulu kwinqwelomoya), zisetyenziswa ikakhulu kwizigqubuthelo zeenjini zenqwelomoya, iziqhoboshi zesantya, ii-antenna. Izigqubuthelo, izizalisi zetanki zamafutha eenqwelomoya, ukusetyenziswa kwe-fuel buoys carburetor buoys, njl., kunye nezakhelo ezahlukeneyo zenkxaso kunye nezihlalo zokuhlala zokuhlobisa kwangaphakathi, kunye nokugquma kwishishini lezothutho.Iikhushini zezihlalo, ifanitshala yendlu, kunye namatayara awohlulwa kwiimveliso zepolyurethane, kwaye uphuhliso lwamva nje kunye nokusetyenziswa kweemveliso kwizixhobo ezifunxa ukothuka kweemoto kubangele ngakumbi.

Nangona zininzi iintlobo zeemveliso ze-polyurethane, ulwahlulo lwemveliso yalo alukho ngaphezu: iimveliso ze-foam eziguquguqukayo, iimveliso eziqinileyo kunye ne-elastomers.

Ukuba isixhobo sokubumba imveliso sixutywe irabha ye-polyurethane, ngokuqhelekileyo iqinile kwaye inokutshatyalaliswa ngesulfure, i-peroxide kunye ne-polyisocyanate, kwaye inokuyilwa ngokwenkqubo yokuvelisa kunye nefomula yeemveliso zerabha eziqhelekileyo.Kwimeko ye-elastomers ye-thermoplastic, inokucutshungulwa ngokubunjwa kwenaliti okanye ukubunjwa koxinzelelo.Kwimeko yeplastiki ye-polyurethane, inokuveliswa nge-tape casting.

Ukuthatha iimveliso ze-polyurethane eziguquguqukayo ze-foam njengomzekelo, inkqubo yemveliso idla ngokuba yi-component-component liquid reaction molding.Oko kukuthi, elinye iqela yimpendulo yokuqala edibeneyo ye-polymer ye-polymer kunye ne-isocyanate, kwaye emva koko i-reactants ingentla ixutywe nelinye iqela eliquka amanzi, i-agent ekhupha ugwebu, i-stabilizer, i-catalyst kunye nee-agent ezincedisayo ezahlukeneyo ukuvelisa i-organic aminoformaldehyde Ester.Kwangaxeshanye, ii-reactants ezifana namaqela e-urea zisebenzisa le ndlela yokusabela ukuvelisa ikharbon diokside, zikhupha ubushushu obuninzi, zize ke zisebenzise ii-catalysts ukulungelelanisa isantya sogwebu, kwaye ekugqibeleni zigqibezele imveliso yogwebu efanayo.

Okwangoku, ishishini lokwenziwa kweemoto lihlala liphucula ngokwemiqathango yokhuseleko, intuthuzelo kunye nokuqina, kwaye kukho iimfuno eziphezulu zokuqina phantsi kweemeko zokusebenza eziphezulu zokothuka kunye nokuthomalalisa iinxalenye ze-elastomer.Uhlobo olutsha lwe-absorber olutsha olwenziwe nge-polyurethane foam ethambileyo luye lwavela kwiimarike zangaphandle, kwaye iimpawu zayo zomzimba kunye noomatshini kunye nefuthe lokudambisa zingcono kancinane kunezo zezixhobo zokudambisa irabha.