Iyini i-polyurethane?Yiziphi izinzuzo kanye nokubi izinto polyurethane?

Kusukela ekuqaleni kokukhiqizwa kwezimboni ngawo-1950, izinto zokwakha ze-polyurethane (okungukuthi, ama-polymers aphezulu e-molecular aqukethe amaqembu e-carbamate ochungechungeni oluyinhloko lwama-macromolecules - i-NHCOO) athuthuke ngokushesha.Uma kuqhathaniswa nezinto zenjoloba ye-polymer, inezici zayo eziyingqayizivele.Ingasebenzisa izinombolo ezihlukene zamaqembu asebenzayo kanye nezinhlobo ezahlukene zamaqembu asebenzayo ngokuvumelana nezidingo ezihlukene zokusebenza, futhi isebenzise izinqubo ezihlukene zokukhiqiza ukukhiqiza imikhiqizo ye-polyurethane enezici ezihlukahlukene zokusebenza nezici.

Kukhona nezinto ezisetshenziswayo ezingekho esigabeni senjoloba, njengamapulasitiki anegwebu, imikhiqizo yepulasitiki eqinile, okokunamathela, imicu yokwenziwa ekwazi ukumelana nokuqina, isikhumba sokwenziwa, izinto zokunamathisela, njll.

Izinto ze-polyurethane okwamanje zisetshenziswa kabanzi emikhakheni ehlukahlukene, isibonelo, embonini ye-aerospace, imikhiqizo yayo eqinile, imikhiqizo ethambile kanye nemikhiqizo yegwebu ilula kunezinto zensimbi (ezibaluleke kakhulu ezindizeni), ezisetshenziswa kakhulu kumasembozo enjini yendiza, amabhuleki esivinini, izimpondo. Amakhava, okokugcwalisa ithangi likaphethiloli wendiza, ama-buoys okulawula ukusetshenziswa kukaphethiloli e-carburetor, njll., kanye namafreyimu ahlukahlukene okusekela kanye nama-cushions ezihlalo zokuhlobisa ingaphakathi, kanye nokufaka izinto embonini yezokuthutha.Amakhushini ezihlalo, ifenisha yasendlini, ngisho namathayi awahlukaniseki emikhiqizweni ye-polyurethane, futhi ukuthuthukiswa kwakamuva nokusetshenziswa kwemikhiqizo yezesekeli ezimunca ukushaqeka kwezimoto kuye kwabangela okwengeziwe.

Nakuba kunezinhlobo eziningi zemikhiqizo ye-polyurethane, ukuhlukaniswa komkhiqizo wayo akuyona into engaphezu: imikhiqizo yegwebu eguquguqukayo, imikhiqizo eqinile kanye nama-elastomers.

Uma umshini wokubumba umkhiqizo uxubene nerabha ye-polyurethane, ngokuvamile iqinile futhi ingavuthwa ngesibabule, i-peroxide ne-polisocyanate, futhi ingaklanywa ngokuya ngenqubo yokukhiqiza kanye nefomula yemikhiqizo yenjoloba evamile.Endabeni ye-thermoplastic elastomers, ingacutshungulwa ngokubunjwa komjovo noma ukubunjwa kokucindezela.Endabeni yepulasitiki ye-polyurethane, ingakhiqizwa nge-tape casting.

Ukuthatha imikhiqizo eguquguqukayo yegwebu le-polyurethane njengesibonelo, inqubo yokukhiqiza ivamise ukubunjwa kwezingxenye ezimbili ze-liquid reaction.Okusho ukuthi, iqembu elilodwa liwukusabela kokuqala okuxubile kwe-polyol polymer ne-isocyanate, bese lezi zinto ezisabelayo ezingenhla zixutshwa nelinye iqembu elihlanganisa amanzi, i-ejenti ephuphumayo, i-stabilizer, i-catalyst kanye nama-agent ahlukahlukene asizayo ukukhiqiza i-organic aminoformaldehyde Ester.Ngesikhathi esifanayo, ama-reactants afana namaqembu e-urea asebenzisa lokhu kusabela ukuze akhiqize i-carbon dioxide, ekhulula inani elikhulu lokushisa, bese esebenzisa ama-catalysts ukulungisa isivinini sokugwetshwa, futhi ekugcineni aqedele umkhiqizo wegwebu elifanayo.

Njengamanje, imboni yokukhiqiza izimoto ihlale ithuthuka mayelana nokuphepha, ukunethezeka nokuqina, futhi kunezidingo eziphakeme zokuqina ngaphansi kwezimo zokusebenza eziphakeme kakhulu zezingxenye ze-elastomer ezibamba ukushaqeka kanye nokumanzisa.Uhlobo olusha lwe-shock absorber elenziwe ngegwebu le-polyurethane elithambile selivele ezimakethe zakwamanye amazwe, futhi izakhiwo zalo ezingokomzimba nezomshini kanye nomphumela wokudambisa zingcono kancane kunezesekeli zokudambisa iraba.