Njikọta Isocyanates na Rubber mmiri na-emeghachi omume HTPB na CTBN

Ihe Ndị Dị Mkpa Ị Ga-eburu n'Obi

• Jikọta roba mmiri mmiri na-abụghị polar na isocyanates aromatic iji wuo ihe ndị dị ọnụ ala, mmiri na-eguzogide, nwere ike dị elu.
• Jikọta isocyanates aliphatic na rọba mmiri mmiri iji mepụta ihe mkpuchi doro anya, nke na-egbochi ihu igwe nke na-eguzogide mmebi anyanwụ.
• Debe nke gị Kemịkalụ NCO ndeksi dị n'etiti 1.02 na 1.08 iji hụ na ọ na-agwọ ọrịa zuru oke ma na-arụ ọrụ siri ike.

Kemịstrị na Nhazi Ọrụ

Mmeghachi omume na Kinetics nke otu Terminal

Ị ga-enwerịrị ike ịdepụta ọsọ mmeghachi omume nke isocyanate ị họọrọ na otu njedebe kpọmkwem nke roba mmiri mmiri gị. Polybutadiene nke Kwụsịrị hydroxyl (HTPB) na-emeghachi omume nke ọma na diisocyanates, ebe ọ bụ na ọ na-emeghachi omume nke ọma na diisocyanates, roba ndị a na-eme ka amine kwụsị (ATBN) Mmeghachi omume ozugbo iji mepụta njikọ siri ike nke polyurea. Mgbe ị na-emepụta diisocyanates asymmetrical dị ka IPDI, ihe mkpali kpọmkwem na-agbanwe mmeghachi omume otu. Dịka ọmụmaatụ, trifluoroacetic acid na-eme ka otu isocyanate bụ isi rụọ ọrụ karịa nke abụọ. Ọdịdị kemịkalụ nke otu akụkụ dị nso na-akpali nhọrọ kinetic a kama igbochi steric.

Ndakọrịta nke Polarity na Solubility Parameter

Ijikọta Isocyanates na Rubber mmiri na-emeghachi omume (HTPB vs. CTBN) chọrọ nyocha nke ọma gbasara nha mmiri. Ọkpụkpụ azụ polybutadiene na-abụghị polar na-eguzogide ịgwakọta na isocyanates polar, aromatic. Ị nwere ike iji ntuziaka a jikọta ọkpụkpụ azụ na ọgwụgwọ:

Ọdịdị Isocyanate na Nhazi nkewa siri ike

Usoro ihe eji eme ka ihe dị n'ime molekul nke Isocyanate na-ekpebi nhazi kristal siri ike na nkewa nke usoro. Usoro ihe eji eme ka ihe dị n'ime symmetric dị ka 4,4'-MDI na-agbakọta nke ọma, na-emepụta ngalaba siri ike nke na-eme ka ike mekanik dịkwuo elu. Monomers ndị na-adịghị agbanwe agbanwe dị ka TDI ma ọ bụ IPDI na-emebi nchikọta nke ọma, na-ebelata viscosity resin ma na-eme ka mgbanwe dị ala na okpomọkụ dịkwuo mma. Ị nwere ike ịhazi ike polymer zuru oke site na ịhazi geometries symmetric na asymmetric.

Njikọta Isocyanates na Rubber Liquid Reactive (HTPB Sistemụ)

Polybutadiene nke Hydroxyl-ended (HTPB) nwere azụ hydrocarbon nke na-anaghị enwe polar, nke na-adịghị amị amị. Ị ga-ahọrọ ọgwụgwọ ndị dabara adaba iji gbochie mmiri ma nọgide na-enwe iguzosi ike n'ezi ihe. Ịdakọtara Isocyanates na Rubber Liquid Reactive (Sistemụ HTPB chọrọ inyocha ma mmeghachi omume kemịkalụ na ihe achọrọ n'ime igwe ikpeazụ.

MDI na TDI maka ndị na-akpọ Hydrophobic Elastom

Diisocyanates na-esi ísì ụtọ dị ka diphenylmethane diisocyanate (MDI) na toluene diisocyanate (TDI) Na-emeghachi omume ngwa ngwa na HTPB hydroxyl end-groups. Ụdị ihe ndị a na-esi ísì ụtọ na-enye ike anụ ahụ pụrụ iche na ọnụ ala dị ala. MDI na-emepụta akụkụ siri ike, nke siri ike nke ukwuu n'ime netwọk elastomeric. Ngwugwu a dị oke arọ na-eme ka ike nrụgide dịkwuo elu ma na-eme ka mgbochi anya dịkwuo elu.

Ọkpụkpụ azụ HTPB (Ọ bụghị polar) + MDI/TDI (Ọ na-esi ísì ụtọ) ===> Elastomer Ọdịdị Hydrophobic 

TDI na-enye obere viscosity mbụ karịa MDI. Ị nwere ike ịwụnye usoro dabere na TDI n'ime ebu dị mgbagwoju anya ngwa ngwa. Agbanyeghị, TDI na-egosipụta nrụgide uzuoku dị elu. Ị ga-ejikwa TDI na ikuku ikuku ọzọ iji chebe ndị ọrụ.

Ọgwụ abụọ a na-esi ísì ụtọ na-echekwa àgwà ndị na-egbochi mmiri nke HTPB. Ha na-echebe elastomer ikpeazụ gị pụọ na mmiri ịmịkọrọ, asịd ndị na-ebelata mmiri, na alkalis mmiri.

Rịba ama: Akụkụ siri ike nke na-esi ísì ụtọ na-emebi n'okpuru ìhè ultraviolet (UV) kpọmkwem. Jiri MDI na TDI mee ihe karịsịa n'ime ebe a kpuchiri ekpuchi, kpuchie ya, ma ọ bụ n'ime ụlọ ebe ọ na-adịghị ihe ọ bụla na-egosi na UV dị.

IPDI na HDI maka Usoro Ndị Na-adịghị Mfe

Aliphatic isocyanates na-edozi nsogbu ịka nká na mmebi ìhè. Isophorone diisocyanate (IPDI) na hexamethylene diisocyanate (HDI) na-eguzogide radieshon UV kpamkpam. Ha na-egbochi uto nke elu na mgbawa n'oge mkpughe n'èzí ogologo oge.

IPDI nwere otu NCO abụọ na-anaghị adabara nhata. Otu NCO bụ isi na-emeghachi omume nwayọ nwayọ, ebe otu NCO nke abụọ na-emeghachi omume ngwa ngwa n'okpuru oke okpomọkụ. Ị nwere ike iji ọdịiche kinetic a chịkwaa ndụ ite na usoro ịtụ ihe gị.

HDI na-enye mgbanwe kwụ ọtọ. Ọdịdị aliphatic ya nke na-agbanwe okpomọkụ nkewa microphase, nke na-echekwa ike mgbanwe ruo n'ọnọdụ dị ala.

• Uru IPDI: Ogologo ndụ ite, usoro ọgwụgwọ a na-achịkwa, nkwụsi ike okpomọkụ dị elu.
• Uru HDI: Ike mgbanwe dị elu nke obere okpomọkụ, ezigbo iguzogide UV, na obere viscosity.

Njikọta Isocyanates na Rubber Mmiri Na-eme Ka Ọ Dịghachi (HTPB na aliphatic curatives na-eme ka anya doo anya, kwụsie ike na agba, na ihe mkpuchi na-eguzogide ihu igwe.

Nhazi Prepolymer na Nhazi Stoichiometry

Ngwakọta otu-ose ozugbo nwere ike ibute mmeghachi omume exothermic a na-achịkwaghị achịkwa na nkewa nke usoro. Ị nwere ike igbochi nsogbu ndị a site na imepụta ihe Prepolymer nke NCO kwụsịrị mbụ. Mmepụta Prepolymer na-ebelata mmepụta okpomọkụ zuru oke n'oge ọgwụgwọ ikpeazụ ma na-ebelata mwepụta monomer na-agbanwe agbanwe.

1. Nkwadebe Mmeghachi omume: Jiri resin HTPB kpọrọ nkụ chajie ihe na-eme ka ... dị n'ime ya.
2. Mwepụ Mmiri: Mmiri na-eme ka resin ahụ dị ọcha na okpomọkụ 90°C iji wepụ mmiri fọdụrụnụ. Mmiri na-emeghachi omume na otu NCO, na-emepụta afụ carbon dioxide na ebe urea na-adịghị ike.
3. Mgbakwunye Isocyanate: Tinye diisocyanate ị họọrọ n'okpuru ákwà mkpuchi nitrogen kpọrọ nkụ.
4. Mgbatị Agbụ A Na-achịkwa: Debe okpomọkụ dị n'etiti 70°C na 80°C ruo mgbe ọdịnaya NCO ga-adaba.

Nzọụkwụ 1: Oke Isocyanate + HTPB ===> Prepolymer NCO-Ekwụsịla + Monomer efu Nzọụkwụ 2: Prepolymer + Agbụ Extender ===> Netwọk Polyurethane a gwọrọ agwọ 

Ị ga-agbakọ stoichiometry gị nke ọma. Debe ihe nrịbama NCO zuru oke (nha nhata nke otu NCO na otu OH) n'ime oke 1.03 ruo 1.06.

$$\text{NCO Index} = \frac{\text{Ngụkọta nha nhata nke NCO}}{\text{Ngụkọta nha nhata nke OH}}$$

Ndekọ NCO dị n'okpuru 1.00 na-ahapụ agbụ HTPB na-anaghị emeghachi omume. Mkpụrụ ndụ mmiri ndị a na-anaghị emeghachi omume na-arụ ọrụ dị ka ihe eji plasticizers achọghị, nke na-ebelata modulus tensile gị ma na-emebi iguzogide kemịkalụ. N'aka nke ọzọ, ndeksi NCO dị n'elu 1.10 na-emepụta njikọ gabigara ókè. Ọtụtụ njikọ na-akpata ọdịda na-adịghị ike n'okpuru ibu mmetụta siri ike. stoichiometry kpọmkwem na-ekwe nkwa arụmọrụ kachasị.

Usoro nhọrọ CTBN, ATBN, na HTBN

Otu akụkụ nke carboxyl, amine, na hydroxyl dị na azụ roba nitrile chọrọ atụmatụ nhọrọ ezubere iche. Ị nwere ike imeziwanye ike mgbawa, iguzogide kemịkalụ, na arụmọrụ okpomọkụ nke ukwuu site na ijikọ roba ndị a na-arụ ọrụ na isocyanates ziri ezi.

Ngwakọta Epoxy-Polyurethane nwere CTBN na MDI

Carboxyl-ended butadiene acrylonitrile (CTBN) nwere otu carboxylic acid dị n'ime ya (-COOH) na azụ polar nitrile. Mmeghachi omume kpọmkwem n'etiti carboxylic acid na diisocyanates na-emepụta njikọ anhydride na-adịghị agbanwe agbanwe ma wepụta gas carbon dioxide. Ị nwere ike iwepụ afụfụ gas site na ịmepụta netwọk ngwakọ epoxy-polyurethane kama.

CTBN + Resin Epoxy karịrị akarị ===> Epoxy-Emechaala Rubber Prepolymer Epoxy Prepolymer + 4,4'-MDI + Agbụ Extender ===> Matrix Ngwakọta siri ike 

Nke mbụ, jiri resin epoxy gabigara ókè mee ihe CTBN iji mepụta roba epoxy-endated intermediate. Na-esote, tinye 4,4'-MDI na ihe ndọtị diol iji wuo azụ polyurethane jikọtara ọnụ gburugburu mpaghara roba ahụ.

Ndụmọdụ Ọkachamara: Debe ihe dị na acrylonitrile (AN) n'ime CTBN n'etiti 18% na 26%Oke AN a kpọmkwem na-akwalite nkewa nke usoro n'oge a na-agwọ ọrịa. Obere mpaghara roba nke nha micron na-apụta na matrix ahụ, na-emepụta ihe mgbochi dị irè megide mgbasa mgbawa.

MDI na-enye akụkụ siri ike na-esi ísì ụtọ nke na-ejikọ na matrix polar. Mgbe nrụgide dị ike rutere na ngwakọ a gwọrọ agwọ, ngalaba CTBN ndị a gbasaara agbasa na-amịkọrọ ike mmetụta. Ị na-enweta ike mgbawa dị elu n'emeghị ka ike mekaniki okpomọkụ ma ọ bụ modulus tensile ghara ịdị irè.

Nhazi urea Amine-Isocyanate kpọmkwem site na iji ATBN

Amine nke a na-akpọ butadiene acrylonitrile (ATBN) nwere otu amine nke mbụ ma ọ bụ nke abụọ nke na-arụ ọrụ (-NH2 ma ọ bụ -NHR). Amines na-emeghachi omume na diisocyanates ozugbo n'ọnọdụ okpomọkụ ụlọ. Ha na-emepụta njikọ siri ike nke polyurea na-enweghị mkpa ihe mkpali sịntetik.

Mgbe ejiri Isocyanates mee ihe na Rubber mmiri mmiri na-emeghachi omume (Sistemụ HTPB ma ọ bụ sistemụ ATBN), ị ga-agbanwerịrị ngwa ngwakọta gị iji jikwaa ọdịiche ndị a. ATBN na-emeghachi omume ngwa ngwa nke na ị ga-eji isi ngwakọta pụrụ iche nwere nrụgide dị elu.

ATBN (Amine Ends) + Isocyanate (NCO) ===> Akụkụ siri ike nke Polyurea (njikọ Bidentate) 

Ngalaba siri ike nke polyurea na-emepụta njikọ siri ike nke bidentate hydrogen. Njikọ anụ ahụ ndị a na-ebuli ebe okpomọkụ nke elastomer gị elu karịa 150°C. Ị na-ewepụkwa nsogbu mmetụta mmiri n'oge nhazi. Ndị otu njedebe nke Amine na-emeghachi omume na NCO ngwa ngwa karịa mmiri gburugburu nwere ike ime.

Ndakọrịta HTBN na Sistemụ Na-eguzogide Mmanụ

Butadiene acrylonitrile nke hydroxyl kwụsịrị (HTBN) na-ejikọta ọrụ hydroxyl (-OH) na ọkpụkpụ azụ nitrile polar. Rubber ndị na-abụghị polar na-ada ngwa ngwa mgbe e tinyere ha na mmanụ ọkụ na-abụghị polar, ihe mgbaze aromatic, ma ọ bụ mmiri hydraulic. Otu acrylonitrile polar dị na HTBN na-achụpụ hydrocarbons, na-echebe elastomer gị pụọ ​​na ọzịza nke ihe mgbaze.

HTBN (Azụ̀ Polar) + IPDI/MDI ===> Ihe Mgbochi Hydrocarbon Na-eguzogide Mmanụ 

Ị ga-ejikọta HTBN na diisocyanates dakọtara iji wuo akara siri ike, gaskets, na tankị mmanụ ọkụ:

• Jikọta HTBN na MDI: Ị na-enweta ike kachasị elu nke igwe, oke mgbochi anya mmiri, na ike akwụkwọ ndụ akwụkwọ ndụ ngwa ngwa maka gaskets ụlọ ọrụ mmepụta ihe.
• Jikọta HTBN na IPDI: Ị ga-enweta ihe mkpuchi tankị mmanụ ọkụ na-agbanwe agbanwe, nke na-anaghị agbaji agbaji n'okpuru mgbanwe okpomọkụ dị iche iche.

Ị nwere ike ịgbanwe ọdịnaya nitrile dị na HTBN iji dozie iguzogide ihe mgbaze. Ọkwa acrylonitrile dị elu na-eme ka polarity dịkwuo elu ma na-eme ka iguzogide mmanụ dịkwuo mma. Agbanyeghị, polarity dị elu na-emekwa ka resin viscosity mbụ dịkwuo elu. Ị kwesịrị ikpo ọkụ HTBN ruo 50°C n'oge degassing iji belata viscosity nhazi tupu itinye diisocyanate ị họọrọ.

Usoro na Usoro Nhazi Dị Mkpa

Nchịkọta Stoichiometric na NCO Index

Ị ga-achịkwa oke stoichiometric n'etiti otu isocyanate na-arụ ọrụ na otu njedebe roba. Lekwasị anya na NCO index n'etiti 1.02 na 1.08 iji hụ na njikọ kemịkalụ zuru oke. Ndepụta dị n'okpuru 1.00 na-ahapụ oligomers na-anaghị emeghachi omume. Mkpụrụ ndụ ndị a na-enweghị ihe ọ bụla na-arụ ọrụ dị ka ihe na-eme ka plastik ghara ịdị mma ma na-ebelata iguzosi ike n'ezi ihe nke nhazi. N'aka nke ọzọ, ndepụta dị n'elu 1.10 na-akpata njikọ gabigara ókè, nke na-eme ka elastomer gị gwọrọ gbawaa.

Nhagharị ngalaba na nkewa nke obere usoro

Nkewa nke microphase na-achịkwa arụmọrụ nke matriks polymer gị a gwọrọ agwọ ozugbo. Ọkpụkpụ roba na-abụghị polar na-achụpụ akụkụ urea polar ma ọ bụ urea siri ike n'ụzọ ebumpụta ụwa. Ị nwere ike ịgbanwe enweghị ike kemịkalụ a iji mee ka njikọ onwe onye dị n'oge ọgwụgwọ. Ngalaba siri ike agbasasị na-arụ ọrụ dị ka njikọ anụ ahụ iji kwalite ike nrụgide. Ka ọ dịgodị, ngalaba rọba dị nro na-aga n'ihu na-echekwa mgbanwe dị ala na okpomọkụ ma na-amịkọrọ ike mmetụta ike.

Nhazi Viscosity na Nhazi Pot-Life

Mgbe ejiri Isocyanates mee ihe na Rubber mmiri na-emeghachi omume (usoro HTPB, ọ na-abụkarị viscosity mbụ dị elu na-egbochi ijupụta ebu na iwepụ ya nke ọmaIhe mgbaze ndị na-anaghị emeghachi omume na-ebelata viscosity, mana ha na-emepụta oghere ndị na-adịghị ike n'oge uzuoku. Kama nke ahụ, HTPB dị oke ala na-arụ ọrụ dị ka ihe na-eme ka mmiri gbazee na usoro polymer, na-enye ohere maka mbelata viscosity dị irè ebe ọ na-echekwa ihe ndị bụ isi nke ihe ahụ.

Ndụmọdụ: Kpoo rọba mmiri mmiri gị ruo 50°C tupu ị tinye ọgwụgwọ iji mee ka ite ahụ dịgide ogologo oge ma mee ka afụ ahụ na-apụ ngwa ngwa.

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• Jikọọ HTPB na-abụghị polar na MDI ma ọ bụ TDI iji mee ka hydrophobicity na obere okpomọkụ dịkwuo mma ma dị ọnụ ala.
• Jikọta HTPB na aliphatic IPDI ma ọ bụ HDI maka iguzogide UV dị elu na ndụ ogologo oge.
• Jiri rọba nitrile (CTBN, ATBN, HTBN) mee ihe n'ime sistemu polar iji mee ka ike mgbawa na iguzogide mmanụ dịkwuo elu.
• Jikwaa stoichiometry nke NCO nke ọma. Oke ziri ezi na-egbochi oligomers ndị na-anaghị emeghachi omume ka ha ghara ime ka elastomer gị daa mbà.

Ajụjụ Ndị A Na-ajụkarị

Kedu otu esi ahọrọ n'etiti MDI na IPDI maka sistemụ HTPB?

Ndụmọdụ Ngwa Ngwa: Dakọtara ọgwụgwọ gị na gburugburu ebe ị na-eji ya.

Họrọ MDI mgbe ịchọrọ ike nrụgide dị elu na ọnụ ala dị ala maka ojiji n'ime ụlọ. Họrọ IPDI maka usoro mpụga nke chọrọ nkwụsi ike UV na ndụ ogologo oge nke ite.

Gịnị mere ị ga-eji nọgide na-enwe ndeksi NCO n'etiti 1.02 na 1.08?

Nkewa a kpọmkwem na-eme ka njikọ kemịkalụ zuru oke. Ọ na-egbochi roba mmiri mmiri na-anaghị emeghachi omume ime ka matriks gị dị nro ma na-egbochi njikọ gabigara ókè site n'ịmepụta elastomer na-agbawa agbawa.

Kedu ka CTBN si eme ka ike mgbawa dị na ngwakọ epoxy-polyurethane ka mma?

CTBN na-abanye n'ime obere mpaghara rọba mgbe a na-agwọ ya. Mpekere rọba ndị a na-amịkọrọ ike mmetụta ma na-akwụsị mgbasa mgbawa n'ime matriks polymer gị a gwọrọ agwọ.