nkhani

Chopangira filimu ndiye gawo lalikulu la cholowetsa ulusi wagalasi, chomwe nthawi zambiri chimakhala 2% mpaka 15% ya gawo lalikulu la fomula yolowetsa, ntchito yake ndikulumikiza ulusi wagalasi kukhala mitolo, popanga chitetezo cha ulusi, kuti mitolo ya ulusi ikhale ndi mulingo wabwino wa kuuma, agglomeration, kuti ikwaniritse zofunikira za ndondomeko yotsatira muzinthu zagalasi za ulusi. Zopangira filimu zomwe zimagwiritsidwa ntchito kwambiri mu mapangidwe agalasi a infiltrant ndi ma polima, kuphatikiza ma epoxy resins, polyurethane, polyester, phenolic resins, modified polypropylene dispersions, kapena emulsions. Kagwiridwe ka zinthu zopangira filimu kumadalira makamaka kapangidwe ka molekyulu ndi kulemera kwa molekyulu ya polima. Kwa chopangira chomwecho chopangira filimu, kuuma kwaulusi wagalasiikhoza kulamulidwa ndi kulemera kwa mamolekyulu a chinthu chopanga filimu, ndipo chinthu chopanga filimu chokhala ndi kulemera kwakukulu kwa mamolekyulu chidzakhala ndi kuuma kwakukulu kwa ulusi wagalasi, womwe ndi woyenera kuchiza pamwamba pa chinthucho.kulimbikitsa zinthu zagalasi zodulidwa ndi thermoplastic, pomwe chopangira filimu chokhala ndi kulemera kochepa kwa mamolekyulu ndi choyenera kupanga ulusi womwe umagwiritsidwa ntchito popangira ndi kukoka. Ma polima a epoxy resin ali ndi magulu a aliphatic hydroxyl, ether, ndi epoxy, ndipo pali kukopana kwakukulu kwa mankhwala pakati pa magulu a polar mu zopangira filimu za epoxy, kotero zimakhala ndi kumamatira bwino komanso kuphatikizika bwino pa ulusi wagalasi;

Kuphatikiza apo, gulu la epoxy lomwe lili mu epoxy film-forming agent limatha kuchitapo kanthu ndi gulu la terminal hydroxyl, gulu la terminal carboxyl, gulu la terminal amino, ndi magulu ena ogwira ntchito mu mapulasitiki opanga monga PBT, PET, PA, PC, ndi zina zotero, kuti liwongolere mphamvu yolumikizirana pakati pa ulusi wagalasi ndi resin. Ma polymer film-forming agents ali ndi magulu ambiri a ester, ma unsaturated chemical bonds, ndi magulu ophikira mu unyolo waukulu, ndipo magwiridwe antchito awo amadalira mtundu wa asidi ndi mowa womwe umagwiritsidwa ntchito popanga polyester ndi chiŵerengero. Pamene base resin ndi unsaturated polyester resin, ma unsaturated double bonds mu polyester film-forming agent amatha kupanga polymer ndi cross-link ndi ma double bonds mu base resin kuti apange chemical bond yamphamvu kapena physical entanglement, zomwe zimawonjezera mphamvu yolumikizirana pakati. Ma polyester film-forming agents nthawi zambiri amakhala ndi mphamvu zabwino kwambiri zonyowetsa ndi kulowa ndipo motero amagwiritsidwa ntchito ngati ma wetting agents mu pultrusion, winding, spraying, chevron, ndi zinthu zina. Unyolo wa molekyulu wa polyurethane wopanga filimu uli ndi kapangidwe ka carbamate kobwerezabwereza, kukhalapo kwa magulu a polar awa kumapangitsa kuti polyurethane ndi ulusi wagalasi zikhale ndi mgwirizano wabwino kwambiri, zigawo zofewa ndi zolimba za molekyulu zomwe zimakhala ndi kusinthasintha kwakukulu komanso kukana kukwawa, nthawi yomweyo, polyurethane yomwe ili mgulu la isocyanate imatha kulowetsedwa ndi amino coupling agent ndi matrix resin mu chemical reaction, kuti ilimbikitse kulumikizana kwa interfacial, kukonza magwiridwe antchito azinthu zopangidwa ndi zinthu zosiyanasiyanazinthu.