Guhuza Isocyanati na Reactive Liquid Rubbers HTPB na CTBN

Ibintu by'ingenzi byakunzwe

• Huza imipira y'amazi itari iy'ibara ry'umuhondo n'iy'isocyanati ihumura neza kugira ngo ukore ibikoresho bihendutse kandi bidashobora amazi kandi bikomeye cyane.
• Huza isocyanati za alifatiki n'udupira tw'amazi kugira ngo ukore ibifunga bisobanutse kandi bidashobora kwangizwa n'izuba.
• Komeza ibyawe imiti ya NCO igipimo kiri hagati ya 1.02 na 1.08 kugira ngo habeho gukira neza no gukora neza.

Ikarita y'Ubutabire n'Imikorere

Uburyo bwo gukora ibikorwa bya Terminal Group Reactivity na Kinetics

Ugomba gushyira hamwe umuvuduko w'ihinduka rya isocyanate wahisemo n'amatsinda yihariye y'umupira wawe w'amazi. Polybutadiene yavuyeho hidroxyl (HTPB) ikora neza hamwe na diisocyanate, mu gihe imipira ivamo amine (ATBN) Guhita bikora kugira ngo bikore imikoranire ikomeye ya polyurea. Iyo ukoze diisocyanates zidafite ingano nka IPDI, catalysts runaka zihindura reactivity y'amatsinda. Urugero, aside trifluoroacetic ikoresha itsinda ry'ibanze rya isocyanate kurusha irindi rya kabiri. Imiterere ya shimi y'amatsinda yo ku ruhande rwegereye ni yo ituma habaho iyi kinetic selectivity aho kuba steric ibangamira.

Guhuza Ibipimo bya Polarite na Solubility

Guhuza Isocyanates na Reactive Liquid Rubbers (HTPB vs. CTBN) bisaba gusuzuma neza ibipimo by'umushongi. Udusimba tw'umugongo twa polybutadiene tudakoresha polar turwanya kuvanga na polar, isocyanates zihumura neza. Ushobora gukoresha ubuyobozi bukurikira kugira ngo uhuze utwo dusimba n'imiti ivura:

Isocyanate Geometry n'imiterere y'ibice bikomeye

Ubusumbane bwa molekile ya Isocyanate bugena imiterere y’ibice bikomeye n’itandukaniro ry’ibice. Imiterere y’ibirungo ingana nka 4,4'-MDI irakomera cyane, bigatuma habaho imiterere ikomeye yongera imbaraga za mekanike. Monomeri zingana nka TDI cyangwa IPDI zibangamira uburyo bwo gupakira hafi, zigabanya ubukana bwa resin kandi zikongera ubushyuhe buke. Ushobora kunoza ubukana bwa polymer muri rusange uhuza imiterere y’ibirungo ingana n’iy’ibirungo.

Guhuza Isocyanati na Reactive Liquid Rubber (HTTPB Systems)

Polybutadiene yavuyeho hidroxyl (HTPB) ifite umugongo wa hydrocarbon udahindagurika cyane, udatera amazi. Ugomba guhitamo imiti ijyanye n'iyo miti kugira ngo irinde ubushuhe kandi ikomeze kuba myiza. Guhuza Isocyanates na Reactive Liquid Rubbers (Sisitemu za HTPB zisaba gusesengura uburyo imiti ikoreshwa mu gupima ubushyuhe n'uburyo ikoreshwa mu gupima ubushyuhe bwa nyuma.

MDI na TDI kuri Elastome zikoresha amazi

Diisocyanate zihumura neza nka diphenylmethane diisosianati (MDI) na toluene diisosianati (TDI) Ikora vuba hamwe na HTPB hydroxyl end-groups. Izi aromatic types zitanga imbaraga zidasanzwe kandi zihendutse. MDI ikora ibice bikomeye kandi bikomeye cyane mu muyoboro wa elastomeric. Iyi pfunyika ikomeye yongera imbaraga zo gukurura no kongera ubushobozi bwo kwirinda amarira.

Umugongo wa HTPB (Utari polar) + MDI/TDI (Impumuro nziza) ===> Elastomer y'imiterere ya Hydrophobic 

TDI itanga ubushyuhe buke bw'ibanze ugereranyije na MDI. Ushobora gusuka imiterere ishingiye kuri TDI mu bimera bigoye byoroshye. Ariko, TDI igaragaza umuvuduko mwinshi w'umwuka. Ugomba gufata TDI ukoresheje umwuka mwinshi kugira ngo urinde ababikora.

Uburyo bwombi bwo kuvura butuma HTPB ikomeza kwirukana amazi karemano. Burinda elastomer yawe ya nyuma kwangirika kw'amazi, aside igabanya ubukana, na alkali zo mu mazi.

Icyitonderwa: Ibice bikomeye bihumura neza birangirika bitewe n'urumuri rwa ultraviolet (UV). Koresha MDI na TDI cyane cyane mu bikoresho bitwikiriwe, bitwikiriwe, cyangwa mu nzu aho ingaruka za ultraviolet zidakomeza kuba nkeya.

IPDI na HDI ku bijyanye n'imashini zihamye z'urumuri

Isosianati za Aliphatic zikemura ibibazo byo gusaza kw'ubushyuhe no kwangirika k'urumuri. Isophorone diisosianati (IPDI) na hexamethylene diisosianati (HDI) birwanya burundu imirasire ya UV. Birinda ko ubuso buhinduka umuhondo cyangwa bucikagurika mu gihe kirekire cyo hanze.

IPDI igizwe n'amatsinda abiri ya NCO adahuje. Itsinda rya mbere rya NCO rikora buhoro buhoro, mu gihe itsinda rya kabiri rya NCO rikora vuba iyo ubushyuhe buri hejuru. Ushobora gukoresha iri tandukaniro rya kinetic kugira ngo ugenzure ubuzima bw'inkono yawe n'uburyo bwo kuyitera.

HDI itanga uburyo bworoshye bwo guhuza. Imiterere yayo ya aliphatic igabanya ubushyuhe bwo gutandukanya microphase, ibi bikaba bituma ubushyuhe bukomeza kwiyongera kugeza kuri sub-zero.

• Inyungu za IPDI: Igihe kirekire cyo gukora mu nkono, imikorere yo kuyitunganya igenzurwa, ubushyuhe bwinshi butuje.
• Inyungu za HDI: Ubushyuhe buke cyane, ubwiyongere bwiza bw'imirasire ya UV, ubushyuhe buke.

Guhuza Isocyanates na Reactive Liquid Rubbers (HTPB na aliphatic curatives bitanga imiterere y'urumuri, ibara rihoraho, kandi bigatera imitako idahindagurika mu gihe cy'ikirere.

Gutunganya Prepolymer na Stoichiometry

Kuvanga inshuro imwe gusa bishobora gutera ingaruka zitagenzurwa zo mu bwoko bwa exothermic ndetse no gutandukana kw'ibyiciro. Ushobora gukumira ibi bibazo ukoresheje uburyo bwo gukora Prepolymer yavuyeho na NCO mbere. Gutunganya prepolymer bigabanya umusaruro w'ubushyuhe mu gihe cyo gushyushya burundu kandi bigabanya imyuka ihumanya ya monomer.

1. Gutegura igisubizo: Shyira ingufu kuri resin yumye ya HTPB muri reactor yawe.
2. Gukuraho ubushuhe: Gukuraho gaze mu buryo bwa vacuum kuri 90°C kugira ngo hakurweho ubushuhe busigaye. Amazi agirana imikoranire n'amatsinda ya NCO, bigatuma habaho utubumbe twa dioxyde de carbone na urea nkeya.
3. Inyongera ya Isocyanate: Shyiramo diisocyanate wahisemo munsi y'igitambaro cyumye cya azote.
4. Kwagura urunigi rugenzurwa: Komeza ubushyuhe buri hagati ya 70°C na 80°C kugeza igihe ingano ya NCO ihagaze neza.

Intambwe ya 1: Isocyanate irenze urugero + HTPB ===> Prepolymer ya NCO-Exterminated + Monomer idafite ingano Intambwe ya 2: Prepolymer + Chain Extender ===> Umuyoboro wa Polyurethane wakize 

Ugomba kubara stoichiometry yawe witonze. Komeza igipimo rusange cya NCO (igipimo kingana na NCO ku matsinda ya OH) kiri hagati ya 1.03 na 1.06.

$$\text{NCO Index} = \frac{\text{Ingano zose za NCO}}{\text{Ingano zose za OH}}$$

Igipimo cya NCO kiri munsi ya 1.00 gisiga imiyoboro ya HTPB idakora neza. Izi molekile z'amazi zidakora neza zikora nk'imashini zikora pulasitiki zidakenewe, bigabanya modulus yawe yo gukurura kandi bikangiza ubushobozi bwo kurwanya imiti. Ku rundi ruhande, igipimo cya NCO kiri hejuru ya 1.10 gitera guhuza cyane. Impande nyinshi zitera kunanirwa gucika intege mugihe cy'ingufu zihinduka. Stoichiometry nziza ihamya imikorere ntarengwa.

Ingamba zo guhitamo CTBN, ATBN, na HTBN

Amatsinda ya Carboxyl, amine, na hydroxyl ku migongo ya nitrile rubber asaba ingamba zo guhitamo zigamije. Ushobora kunoza cyane gukomera kw'amavunika, kurwanya imiti, no gukora neza k'ubushyuhe uhuza izi rubber zifite imikorere n'isocyanate zikwiye.

Epoxy-Polyurethane Hybrides hamwe na CTBN na MDI

Acrylonitrile ya butadiene (CTBN) igizwe n'amatsinda ya aside karubokisilike (-COOH) n'umugongo wa nitrile wo mu gice cy'inyuma cy'amazi. Impuzandengo zitaziguye hagati ya aside karubokisilike na diisocyanates bitanga isano idahamye ya anhydride kandi bigasohora gaze ya dioxyde de carbone. Ushobora gukuraho utubumbe twa gaze ukoresheje imiyoboro ya epoxy-polyurethane hybrid.

CTBN + Epoxy Resin irenze urugero ===> Epoxy-Terminated Rubber Prepolymer Epoxy Prepolymer + 4,4'-MDI + Chain Extender ===> Toughened Hybrid Matrix 

Ubwa mbere, shyiramo CTBN ukoresheje resin ya epoxy irenze kugira ngo habeho icyuma gikoreshwa mu gupima epoxy. Hanyuma, ongeramo 4,4'-MDI n'umuyoboro wa diol kugira ngo ukore urutirigongo rwa polyurethane rufatanye n'urundi ruhande rw'urutirigongo.

Inama y'inzobere: Bika ibikubiye muri acrylonitrile (AN) mu CTBN iri hagati ya 18% na 26%. Uru rwego rwihariye rwa AN rutuma habaho gutandukana kw'ibice mu gihe cyo gushya. Uduce duto twa rubber ingano ya mikoroni dusohoka muri matrix, bigatuma habaho imbogamizi zikomeye zo kwirinda gukwirakwira kw'iminyururu.

MDI itanga ibice bikomeye bihumura neza bifatanya na matrix ya polar. Iyo stress ihinduka ku bwoko bwa hybrid bwakize, izi domaine za CTBN zitatanye zifata ingufu z'ingaruka. Ugira imbaraga zo gucika intege cyane utitaye ku bushyuhe cyangwa uburyo bwo gukurura.

Uburyo bwa Amine-Isocyanate Urea bukorwamo ATBN

Amine-terminated butadiene acrylonitrile (ATBN) ifite amatsinda y’amine abanza cyangwa ay’inyongera (-NH2 cyangwa -NHR). Amine zigira ingaruka hamwe na diisocyanates ako kanya ku bushyuhe bw’icyumba. Zikora imiyoboro ikomeye ya polyurea idakeneye catalysts za sintetike.

Iyo uhuza Isocyanate na Reactive Liquid Rubber (Sisitemu za HTPB cyangwa sisitemu za ATBN), ugomba guhindura ibikoresho byawe byo kuvanga kugira ngo uhangane n'iri tandukaniro rya kinetic. ATBN ikora vuba cyane ku buryo ugomba gukoresha imitwe yihariye yo kuvanga ifite umuvuduko mwinshi.

ATBN (Amine Ends) + Isocyanate (NCO) ===> Ibice bikomeye bya Polyurea (Guhuza Bidentate) 

Uduce duto twa polyurea dukomokamo dukora imigozi ikomeye ya hydrogen. Iyi migozi ihuza imiterere y’umubiri yongera ubushyuhe bwa elastomer yawe hejuru ya 150°C. Nanone kandi, bikuraho ibibazo byo kwangirika k’ubushuhe mu gihe cyo kuyitunganya. Amatsinda ya amine akorana na NCO vuba cyane kurusha uko amazi yo mu kirere ashobora kubikora.

Uburyo HTBN Ikorana na Sisitemu Irwanya Amavuta

Ubutadiene acrylonitrile (HTBN) butadiene yavuyeho hidroxyl Ihuza imikorere ya hydroxyl (-OH) n'umugongo wa nitrile wo mu gice cy'inyuma. Ingufu zitari zo mu gice cy'inyuma zinanirwa vuba iyo zihuye n'ibicanwa bitari byo mu gice cy'inyuma, ibintu bihumura neza, cyangwa amazi ya hydraulic. Amatsinda ya acrylonitrile yo mu gice cy'inyuma muri HTBN yirukana hydrocarbons, ikarinda elastomer yawe kubyimba kw'ibicanwa.

HTBN (Umugongo w'Isonga) + IPDI/MDI ===> Uruzitiro rwa Hydrocarboni rudakoresha lisansi 

Ugomba guhuza HTBN na diisocyanates zijyanye nayo kugira ngo ukore seal, gaskets, na liner za lisansi ziramba:

• Huza HTBN na MDI: Ugera ku bukomere bukabije bwa mekanike, udashobora kwangirika cyane, kandi ukagira imbaraga zihuse z'icyatsi kibisi kuri gasket zo mu nganda.
• Huza HTBN na IPDI: Ubona irangi ry'ibigega bya lisansi rihindagurika kandi rihoraho mu buryo bwa UV, ririnda gucikagurika mu gihe cy'impinduka z'ubushyuhe.

Ushobora guhindura ingano ya nitrile muri HTBN kugira ngo uhindure ubushobozi bwo kurwanya solvent. Urugero rwinshi rwa acrylonitrile rwongera polarity kandi rukongera ubushobozi bwo kurwanya lisansi. Ariko, polarity nyinshi yongera ubushobozi bwo gushyushya resin. Ugomba gushyushya HTBN kugeza kuri 50°C mu gihe cyo gukuramo imyuka kugira ngo ugabanye ubushobozi bwo gutunganya mbere yo gushyiramo diisocyanate wahisemo.

Ibipimo by'ingenzi byo gutegura no gutunganya

Ibipimo bya Stoichiometric n'igenzura ry'ibipimo bya NCO

Ugomba kugenzura neza igipimo cya stoichiometric hagati y’amatsinda ya isocyanate akorana n’amatsinda ya rubber end-groups. Gerageza ku gipimo cya NCO kiri hagati ya 1.02 na 1.08 kugira ngo urebe ko imiti ihuza neza. Igipimo kiri munsi ya 1.00 gisiga oligomers zidakora neza. Izi molekile zikora nk'imashini zikora plastike zidakenewe kandi zigagabanya ubuziranenge bw'imiterere. Ku rundi ruhande, igipimo kiri hejuru ya 1.10 gitera guhuza cyane, bigatuma elastomer yawe ivurwa icika intege.

Ishusho y'aho ibintu biherereye n'itandukaniro rya mikoro

Gutandukanya microphase bigenga imikorere ya mashini ya matrix ya polymer yawe yavuwe. Imigongo ya rubber itari polar isanzwe yirukana ibice bikomeye bya urethane polar cyangwa urea. Ushobora guhindura uku kudahuza kwa shimi kugira ngo wishyire hamwe mu gihe cyo gushonga. Imiterere ikomeye yatanye ikora nk'imirongo ihuza imiterere kugira ngo yongere imbaraga zo gukurura. Hagati aho, imiterere yoroshye ya rubber ikomeza kugumana ubworoherane mu bushyuhe buke kandi ikanyunyuza ingufu z'ingufu zihinduka.

Gutunganya Ubukana n'Uburyo bwo Kunoza Ubuzima bw'Inkono

Iyo uhuza Isocyanates na Reactive Liquid Rubbers (imiti ya HTPB, akenshi ifite viscosity nyinshi bibangamira kuzuza neza imyuka no kuyikuraho neza. Ibinyabutabire bidakora neza bigabanya ubushyuhe, ariko bitera ubushyuhe buke mu gihe cyo guhumeka. Ahubwo, HTPB ifite uburemere buke cyane bw’ibinyabutabire ikora nk'umusemburo ugabanya ubushyuhe mu buryo bwa polymer, bigatuma ubushyuhe bugabanuka neza mu gihe ibungabunga imiterere y’ibanze y’ibikoresho.

Inama: Shyushya irabu yawe y'amazi kugeza kuri dogere selisiyusi 50 mbere yo kongeramo umuti wo kuvura kugira ngo wongere igihe cyo gukora mu nkono no kwihutisha kurekura ibibuno.

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• Huza HTPB itari polar na MDI cyangwa TDI kugira ngo wongere ubushobozi bwo kudakoresha amazi n'ubushyuhe buri hasi kandi byoroshye ku giciro gito.
• Huza HTPB na aliphatic IPDI cyangwa HDI kugira ngo urusheho kwihanganira UV kandi umara igihe kirekire mu nkombe.
• Koresha imipira ya nitrile (CTBN, ATBN, HTBN) muri sisitemu y'izuba kugira ngo wongere imbaraga zo kuvunika no kurwanya amavuta.
• Genzura neza stoichiometry ya NCO. Ibipimo nyabyo birinda oligomer zidakora neza kudatuma elastomer yawe icika intege.

Ibibazo Bikunze Kubazwa

Ni gute wahitamo hagati ya MDI na IPDI kuri sisitemu za HTPB?

Inama yihuse: Huza uburyo bwawe bwo kuvura n'aho porogaramu yawe iherereye.

Hitamo MDI iyo ukeneye imbaraga nyinshi zo gukurura no ku giciro gito mu gukoresha mu nzu. Hitamo IPDI ku miti yo hanze isaba uburimbane bwa UV no kumara igihe kirekire mu nkono.

Kuki ugomba kugumana igipimo cya NCO kiri hagati ya 1.02 na 1.08?

Iyi ratio yihariye ituma habaho guhuza kw'ibinyabutabire neza. Irinda koroshya icyuma cy'amazi kidakoreshejwe neza kandi ikabuza guhuza cyane gukora elastomer ishaje.

Ni gute CTBN yongera ubukana bw'ivunika mu bivange bya epoxy-polyurethane?

CTBN yinjira mu duce duto twa rubber mu gihe cyo kuyitunganya. Utu duce twa rubber duto cyane dufata ingufu z'ingaruka kandi tugahagarika ikwirakwira ry'imivuniko muri matrix yawe ya polymer yavuwe.