1.Mankhwala oletsa hydrolysisCholinga chachikulu ndikuletsa njira yothira madzi m'ma polima a polyester.

Mu ntchito zomwe zimagwiritsidwa ntchito ndi ma polima okhala ndi ma ester bond, monga PBT, PET, PLA, ndi polyurethanes (TPU, CPU), mamolekyu amadzi amaukira mosavuta ma ester kapena urethane bond mu unyolo wa mamolekyu pansi pa kutentha kwakukulu ndi chinyezi. Izi zimapangitsa kuti unyolo usweke ndi hydrolysis, kuchepa kwa kulemera kwa mamolekyu a polima, ndipo chifukwa chake, kusweka, kusweka, ndi kutayika kwa magwiridwe antchito. Ma anti-hydrolysis agents amagwiritsidwa ntchito polimbana ndi njira iyi ya hydrolysis. Ma anti-hydrolysis agents amagawidwa m'magulu awiri: oyambitsa ndi oyambitsa. Ma anti-hydrolysis agents oyambitsa amachotsa malo oyambira kapena zinthu za hydrolysis kudzera mu zochita za mankhwala, zomwe zimayimira njira yayikulu komanso yothandiza kwambiri. Ma anti-hydrolysis agents oyambitsa, kumbali ina, amatseka kapena kuyamwa chinyezi kudzera mu zochita zathupi.

Zoletsa hydrolysis zakuthupi sizitenga nawo mbali mu zochita za mankhwala koma zimaletsa kulowa kwa chinyezi kudzera munjira zakuthupi. Mitundu yoyimira imaphatikizapo zeolites, calcium oxide (CaO), diatomaceous earth, silane, ndi waxes. Zeolites ndi calcium oxide, kudzera mu kapangidwe kawo kokhala ndi mapoko kapena zochita za mankhwala, zimayamwa ndikutseka chinyezi chomwe chimayamwa ndi polima panthawi yokonza ndikugwiritsa ntchito, makamaka kuteteza zinthu kuti zisawonongeke chifukwa cha kuchuluka kwa chinyezi musanagwiritse ntchito (monga kupanga jakisoni ndi kutulutsa), makamaka zimagwira ntchito ngati "desiccant". Silane ndi waxes, kumbali ina, zimasamukira pamwamba pa chinthucho, ndikupanga chotchinga cha hydrophobic, kapena kukulitsa njira yolowera chinyezi kudzera mu zodzaza (monga dongo), makamaka kuteteza pamwamba pa chinthucho.

Zoletsa za hydrolysis zomwe zimayambitsa hydrolysis zimatha kuchitapo kanthu ndi magulu a carboxyl (-COOH) kumapeto kwa unyolo wa polima kapena ndi magulu a carboxyl omwe amapangidwa panthawi ya hydrolysis, zomwe zimasokoneza njira yodziyimira yokha ya hydrolysis motero zimapangitsa kuti pakhale kukhazikika kwakukulu. Izi makamaka zimaphatikizapo zoletsa za carbodiimide, oxazoline, epoxy, ndi aziridine hydrolysis.

2. Carbodiimide ndiye choletsa hydrolysis chothandiza kwambiri komanso chogwiritsidwa ntchito kwambiri.

Pakadali pano ma Carbodiimides ndi gulu logwiritsidwa ntchito kwambiri komanso lothandiza kwambiri la mankhwala oletsa hydrolysis. Amachitapo kanthu ndi magulu a carboxyl opangidwa ndi polymer hydrolysis kuti apange N-acylurea yokhazikika, motero amachotsa chothandizira cha hydrolysis reaction ndikusokoneza autocatalytic cycle. Ma Oxazoline derivatives, gulu lina lofunika la mankhwala oletsa hydrolysis, ali ndi mphete ya oxazoline ngati gulu lawo logwira ntchito. Mphete ya oxazoline imatha kuchitapo kanthu ndi magulu a carboxyl ndi hydroxyl kuti apange ester amides kapena diesters, motero kukhazikika kumapeto kwa polymer. Ma polima ogwiritsidwa ntchito ndi epoxy amagwiritsa ntchito reactivity yayikulu ya magulu a epoxy kuti apereke kukhazikika. Magulu a epoxy amatha kuchitapo kanthu ndi magulu a carboxyl, hydroxyl, komanso amino, potero amatseka magulu awa oletsa.

Gome: Kuyerekeza kwa Zotsutsa za Common Reactive Hydrolysis

Mitundu ya mankhwala oletsa hydrolysis	kabodiimide	Ma polima a gulu logwira ntchito la epoxy	Oxazolinides
Njira Yaikulu	Zimakhudzana ndi magulu a carboxyl opangidwa ndi hydrolysis kuti apange N-acylurea yokhazikika, motero zimasokoneza kayendedwe ka autocatalytic.	Gulu lake la epoxy limatha kuchitapo kanthu ndi magulu osiyanasiyana monga carboxyl, hydroxyl, ndi amino.	Mphete yake ya oxazoline imatha kuchitapo kanthu ndi magulu a carboxyl ndi hydroxyl.
Ubwino waukulu	●Kukana kwambiri hydrolysis, komwe kumakhala ndi zotsatirapo zazikulu kwambiri.	●Kugwira ntchito zambiri: Kumaphatikiza ntchito za kukulitsa unyolo ndi kukonza mamolekyu omwe awonongeka.	● Kuchitapo kanthu kwa ntchito ziwiri, ndi ntchito zosiyanasiyana
	Kuchuluka kwa zinthu zomwe zawonjezeredwa ndi kochepa (0.5%-2.0%), ndipo sikukhudza kwambiri mawonekedwe a chinthucho.	● Zingathandize kusungunuka kwa madzi ndi kukhuthala kwa madzi	● Ingagwiritsidwe ntchito ngati chogwirizanitsa m'machitidwe ena.
	● Chitetezo chabwino	● Kugwirizana bwino ndi ma polima
Zoyipa zazikulu	● Mtengo wake ndi wokwera kwambiri	●Pokhala chinthu chimodzi choletsa hydrolysis, mphamvu yake si yofanana ndi ya carbodiimide.	● Nthawi zambiri mitengo imakhala yokwera mtengo kwambiri
	● Amayang'ana makamaka magulu a carboxyl; sachitapo kanthu mwachindunji ndi magulu a hydroxyl.	● Kuwonjezera kwambiri kungayambitse kulumikiza kapena kugawanitsa.	● Sichithandiza kwambiri pa ntchito zonse zomwe zimagwiritsidwa ntchito
Ntchito zachizolowezi	● Polyester: PBT, PET, PLA, PBAT	● Kubwezeretsanso pulasitiki: Kukonza rPET, ndi zina zotero.	● Polyester (PET, PBT)
	● Polyurethane: TPU, CPU (zopondera nsapato, mapayipi, ndi zina zotero)	● Polyamide (Nayiloni)	●Polyamide
		● Machitidwe a polyester omwe amafuna kukhuthala nthawi imodzi	● Aloyi ya polimeri (monga chogwirizanirana)

 

3. Carbodiimide imaletsa njira ya hydrolysis mwa kuchitapo kanthu ndi ma carboxylic acid kuti apange mapangidwe a acylurea.

Ma polima a polyester samakhala ndi chinyezi chokwanira. Pa kutentha kwambiri komanso chinyezi, ma ester bond mu polima amachita ndi madzi, zomwe zimapangitsa kuti kapangidwe ka unyolo wautali ka macromolecule kasweke ndikupanga magulu a carboxyl. Magulu a carboxyl awa amatha kupanga ma H+ ioni, zomwe zimapangitsa kuti hydrolysis reaction ikhale ndi asidi, zomwe zimapangitsa kuti zinthu zosiyanasiyana zichepetse kwambiri komanso kuti moyo wautumiki ukhale waufupi kwambiri. Ma carbohydrate, omwe ali ndi magulu ogwira ntchito a carbodiimide (N=C=N), amatha kuchita ndi magulu a carboxyl omwe amapangidwa panthawi ya polymer hydrolysis kuti apange mapangidwe a acylurea okhazikika, nthawi yomweyo kuchepetsa kuchuluka kwa gulu la carboxyl ndikuletsa hydrolysis yowonjezera. Ndi amodzi mwa mankhwala oletsa hydrolysis omwe amagwiritsidwa ntchito kwambiri omwe alipo pakadali pano.

Mankhwala oletsa hydrolysis a Carbodiimide ndi osiyanasiyana ndipo amatha kugawidwa m'magulu a monomeric ndi polymeric. Mankhwala a monomeric carbodiimide ali ndi gulu limodzi lokha la carbodiimide ndipo ndi mankhwala ang'onoang'ono a mamolekyulu. Mankhwala a polymeric carbodiimide nthawi zambiri amakhala ndi magulu awiri kapena angapo a carbodiimide, amakhala ndi kulemera kwakukulu kwa mamolekyulu, ndipo ali m'gulu la kapangidwe ka polymer kautali.

Monomeric carbodiimidemankhwala oletsa hydrolysisNdi zamadzimadzi kapena makhiristo owala achikasu mpaka bulauni kutentha kwa chipinda. Zimasungunuka mu zosungunulira zachilengedwe koma sizisungunuka m'madzi, ndipo zili ndi ubwino monga kuyera kwambiri, kukonzekera kosavuta, komanso kuchita zinthu mwachangu. 2,6-Diisopropylphenyl)carbodiimide ndiye mankhwala oletsa hydrolysis a monomeric carbodiimide omwe amagwiritsidwa ntchito kwambiri pamsika.

 

Ma carbodiimides a polymeric ndi ufa wachikasu mpaka bulauni kapena zakumwa zokhuthala kutentha kwa chipinda, ndi kulemera kwa mamolekyulu nthawi zambiri kumakhala kopitilira 1000, pomwe kulemera kwa mamolekyulu a oligomers kumayendetsedwa pafupifupi 2000. Ma carbodiimides a polymeric nthawi zambiri amapezeka pochita ma monomers a diisocyanate, ma catalysts, ma solvents, ndi ma end-capping agents kutentha koyenera. Choyamba, ma diisocyanate monomers amakumana ndi condensation reaction pansi pa catalyst kuti apeze prepolymer yokhala ndi magulu angapo a carbodiimide ndi magulu a isocyanate end. Kenako, magulu a isocyanate amachita ndi active hydrogen kuchokera ku end-capping agent kuti apeze ma polycarbodiimides. Ma polycarbodiimides wamba amapezeka pochita ma condensation a 2,4,6-triisopropylphenyl-1,5-diisocyanate ndi end-capping ndi 2,6-diisopropylphenyl monoisocyanate.

 

4. Malo omwe amagwiritsidwa ntchito nthawi zambiri a carbodiimide

PET, monga chinthu chodziwika bwino cha polyester, ili ndi mphamvu zabwino kwambiri zamakaniko, kukhazikika kwa mawonekedwe, kukana mankhwala, ndi mphamvu zowunikira, ndipo imagwiritsidwa ntchito kwambiri m'minda yaulimi, mafakitale, zomangamanga, zamankhwala, ndi magalimoto. PET imapangidwa kudzera mu polycondensation ya PTA ndi ethylene glycol; ma ester bond amatha kuwonongeka kwambiri ndi hydrolytic, zomwe zimapangitsa kuti kukhuthala kwa polymer kuchepe komanso kuwonongeka kwakukulu kwa magwiridwe antchito. PET hydrolysis imachepetsa kugwiritsa ntchito zinthu zake zapansi pamadzi m'malo otentha kwambiri, chinyezi, kapena akunja. Kafukufuku wofanana wapeza kuti kuphatikiza monomeric anti-hydrolysis agents mu PET masterbatch kukonzekera zitsanzo zamafilimu kumathandizira kukana kutentha, kukalamba kutentha, komanso kutalikitsa zinthu zamafilimu. Aromatic carbodiimide imasonyeza bwino kwambiri hydrolysis performance.

Kupanga kwa polyurethane kumagwiritsa ntchito mitundu yosiyanasiyana ya ma monomers, kumalola kuti zinthu ziyende bwino, komanso kumapereka zabwino monga mphamvu zambiri, kukana kukwawa, kukana kutentha bwino, komanso kusavuta kuikonza. Imagwiritsidwa ntchito kwambiri mu zomatira, zokutira, ma elastomers, mapulasitiki opangidwa ndi thovu, ndi ulusi wopangidwa. Polyurethane yamtundu wa polyester imapangidwa kuchokera ku polyols ya polyester ya oligomeric, yomwe ili ndi ma ester bond ambiri mu unyolo wawo wa mamolekyu, zomwe zimapangitsa kuti hydrolysis isagwire bwino ntchito. Carbodiimide anti-hydrolysis agents imakhala ndi zotsatira zochepa pa polyurethane synthesis ndipo imatha kuwonjezeredwa ku polyester polyol panthawi yopangira. Kuphatikiza apo, polymeric carbodiimides yokonzedwa ndi isocyanate condensation ili ndi magulu a -N=C=O, zomwe zimawathandiza kutenga nawo mbali mu reaction kuti akonze polyurethane yosagwira hydrolysis. Kuphatikiza apo, carbodiimides imatha kuwonjezeredwa panthawi yosakaniza polyurethane. Kafukufuku wofanana wasonyeza kuti kuwonjezera kwa carbodiimides kumatha kuchepetsa asidi woyambirira wa polyester polyol, kuletsa polyester hydrolysis, ndikuwonjezera bwino kukana kwa hydrolysis kwa TPU.

Ma polima osinthika pogwiritsa ntchito polyester monga PBAT, PLA, ndi polyglycolic acid (PGA) ali ndi mphamvu zabwino zogwirizanitsa zinthu, zosinthika, chitetezo, zopanda poizoni, komanso ali ndi mphamvu zabwino zakuthupi ndi zamakanika, zomwe zikuwonetsa chiyembekezo chachikulu mu zida zamankhwala, zida zopakira, ndi ulimi. Komabe, zinthuzi zosinthika zonse zimakhala ndi vuto la hydrolytic ndi kutentha pang'ono, zimawonongeka mosavuta panthawi yokonza, kusungira, ndi kugwiritsa ntchito, zomwe zimapangitsa kuti magwiridwe antchito azichepa komanso kulephera kufika pa nthawi yomwe amayembekezeredwa. Carbodiimide imatha kukhudzidwa ndi magulu a carboxyl omwe ali mu unyolo wa mamolekyulu a PBAT, PLA, ndi PGA kuti apange kapangidwe ka acylurea kokhazikika, nthawi yomweyo kuletsa hydrolysis ndikuwonjezera kukhazikika kwa kutentha.

MDI yosinthidwa ndi Carbodiimide (yomwe imadziwikanso kuti MDI yosungunuka) ndi imodzi mwa zinthu zazikulu zosinthidwa za diphenylmethane diisocyanate (MDI). Imapangidwa ndi condensation reaction ya MDI pogwiritsa ntchito chothandizira kupanga magulu a carbodiimide. MDI yosinthidwa ndi Carbodiimide imadziwika ndi kukhala yamadzimadzi kutentha kwa chipinda, yosavuta kusunga, komanso kukhala ndi moyo wautali. Nthawi yomweyo, imatha kusintha kwambiri kukana kwa hydrolysis kwa zinthu za polyurethane.

Ngati mukufuna kudziwa zambiri za mankhwala oletsa hydrolysis, musazengereze kuteroLumikizanani nafe.