Chii chinonzi Moisture-cured polyurethane

Chii chinonzi Moisture-cured polyurethane

Unyoro-yakagadziriswa polyurethane is one-part polyurethane kuti kurapa kwayo kunotangira hunyoro hwezvakatipoteredza. Iyo munyoro-inorapika polyurethane inonyanya kuve neisocyanate-yakamiswa pre-polymer. Mhando dzakasiyana dzepre-polymer dzinogona kushandiswa kupa inodiwa pfuma. Semuyenzaniso, isocyanate-yakapera polyether polyols inoshandiswa kupa yakanaka kuchinjika nekuda kwekudzika kwayo kwegirazi tembiricha. Kubatanidza chikamu chakapfava, senge polyether, uye chikamu chakaomarara, senge polyurea, inopa kuomarara kwakanaka uye kuchinjika kwejasi. Uyezve, zvivakwa zvinodzorwawo nekusarudza marudzi eisocyanates kuti abatanidze ne pre-polymer.

Mhando mbiri huru dze isocyanates dzinonhuhwirira isocyanate uye aliphatic isocyanate. Inonhuhwirira isocyanate ine yakakwira reactivity. Nekudaro, ine kusasimba kwekunze kwekugara uye kuomarara kwakakomba. Mimwe mienzaniso yeanonhuwirira isocyanate toluene diisocyanate(TDI) uye 4,4'diphenylmethane diisocyanate(MDI). Kune rimwe divi, aliphatic isocyanate, senge, isophorone diisocyanate (IPDI), inopa yakanakisa mamiriro ekunze uye. ruvara kuchengetedza; zvisinei, iyo reactivity yealiphatic isocyanate yakaderera, saka mamwe macatalyst anogona kudiwa. Naizvozvo, mhando dze isocyanate dzakakosha kuti uwane inodiwa pfuma. Uyezve, zvinowedzera, zvinonyungudutsa, pigment, nezvimwe zvinogona kuwedzerwa zvichienderana nekushandisa. Nekudaro, zviwanikwa zvemwando-yakarapwa polyurethanes zvinofanirwa kudzorwa kuti dzisanyorova kuitira kuti dziwane kuchengetedza kugadzikana uye firimu pfuma.

Imwe mukana we mwando-kupora polyurethane ndechokuti chimwe chikamu. Nokudaro, zviri nyore kushandisa sezvo pasina chiyero chakakodzera chekusanganiswa chinodiwa, kana zvichienzaniswa nezvikamu zviviri zvekuputira. Iyo mwando-yakaporeswa PU inobatanidzwa nekuita kweIsocyanate-yakamiswa pre-polymer uye mvura mumhepo, ichigadzira maamine uye shoma shoma yekabhoni dhaibhorosi. Pakupedzisira, kuita kwemaamine uye yakasara isocyanate-yakamiswa pre-polymer inoitika iyo, inoumba urea linkage.