Te Whakataurite i ngā Isocyanates me ngā Rapa Wai Tauhohe HTPB me CTBN
Ngā Whakaaro Matua
- Tātaitia ngā rapa wai kore-porowhita ki ngā isocyanate kakara hei hanga rauemi iti te utu, ātete-wai, engari he kaha nui.
- Whakakotahitia ngā isocyanate aliphatic me ngā rapa wai hei hanga i ngā hiri mārama, ātete ki te huarere, e ātete ana ki ngā kino o te rā.
- Puritia tō Matū NCO i waenga i te 1.02 me te 1.08 hei whakarite kia pakari rawa te āhua me te kaha o te mahi.
Te Mahere Matū me te Mahi
Te Tauhohenga me te Kinetika o te Rōpū Whakamutunga
Me mahere e koe te tere tauhohenga o te isocyanate i whiriwhiria e koe ki ngā rōpū pito motuhake o tō rapa wai. Te polybutadiene kua whakamutua te hauwai-kōpū (HTPB) ka tauhohe mārie ki ngā diisocyanates, i te wā ngā rapa kua whakamutua ki te amine (ATBN) ka tauhohe tonu ki te hanga hononga polyurea kaha. Ina hangaia e koe ngā diisocyanates kore taurite pēnei i te IPDI, ka whakarerekēhia e ngā whakakorikori motuhake te tauhohenga rōpū. Hei tauira, ka whakahohehia e te waikawa trifluoroacetic te rōpū isocyanate tuatahi i runga ake i te tuarua. Ko te āhua matū o ngā rōpū taha tata e akiaki ana i tēnei whiriwhiringa nekeneke kaua ki te aukati steric.
Te Taurite i ngā Tawhā o te Pōra me te Wairewatanga
Ko te whakataurite i ngā Isocyanates ki ngā Rapa Wai Tauhohe (HTPB vs. CTBN) me āta arotake i ngā tawhā wairewa. Kāore ngā tuara polibutadiene kore-polar e ātete ki te whakaranu ki ngā isocyanates kakara polar. Ka taea e koe te whakamahi i te aratohu e whai ake nei hei whakataurite i ngā tuara me ngā rongoā:
| Momo Rapa Wai | Rōpū Mahi | Taurite Isocyanate Pai rawa atu | Painga Mahi Matua |
|---|---|---|---|
| Kore-Polar (HTPB) | -Āe | TDI / MDI / IPDI | Te Āhua Pai o te Wai |
| Pōra (CTBN) | -COOH | MDI / Ngā Ranu Epoxy | Ātete Pānga Teitei |
Te Āhuahanga Isocyanate me te Hanganga Wāhanga Mārō
Ko te ōritetanga ngota ngota isocyanate te mea e whakatau ana i te whakatiotanga o te wāhanga mārō me te wehenga ā-wāhanga. Ka piri ngā hanganga kakara ōrite pērā i te 4,4'-MDI, ka hanga he rohe mārō e whakanui ana i te kaha ā-ringa. Ka whakararuraru ngā monomer kore ōrite pērā i te TDI, i te IPDI rānei i te tākai tata, ka whakaiti i te matotoru o te kapia, ka whakarei ake i te ngāwari o te pāmahana iti. Ka taea e koe te whakatikatika i te pakari whānui o te polymer mā te whakataurite i ngā āhua ōrite me ngā āhua kore ōrite.
Te Whakaōrite i ngā Isocyanate ki ngā Rapa Wai Tauhohe (Ngā Pūnaha HTPB)
He tino kore-polar, he hydrophobic te pūtake o te hydrocarbon o te Hydroxyl-terminated polybutadiene (HTPB). Me whiriwhiri e koe ngā rongoā hototahi hei pupuri i te ātete makuku me te pupuri i te hanganga tika. Ko te whakataurite i ngā Isocyanates ki ngā Rapa Wai Tauhohe (ngā pūnaha HTPB me tātari i te tauhohenga matū me ngā tono miihini whakamutunga.
MDI me TDI mō ngā Elastomers Hydrophobic
Ngā diisocyanate kakara pērā i te diphenylmethane diisocyanate (MDI) me te toluene diisocyanate (TDI) tere te tauhohe ki ngā rōpū mutunga hydroxyl HTPB. Ka tukuna e ēnei momo kakara he kaha ā-tinana tino pai, he iti hoki te utu. Ka hangaia e te MDI ngā wāhanga mārō, he matotoru, he tino tioata i roto i te whatunga elastomeric. Ka whakanui ake tēnei tākai matotoru i te kaha kume me te ātete ki te haehae.
HTPB Backbone (Kore-polar) + MDI/TDI (Kakara) ===> Elastomer Hanganga Waipēhi He iti ake te matotoru tīmatanga o te TDI i te MDI. Ka taea e koe te riringi i ngā hanganga e hangai ana ki te TDI ki roto i ngā pokepokea uaua. Heoi, he teitei ake te pēhanga kohu o te TDI. Me whakamahi koe i te hauhautanga tāpiri hei tiaki i ngā kaiwhakahaere.
| Momo Isocyanate | Taumata Matatini | Te Auau Tauhohenga | Painga Matua |
|---|---|---|---|
| MDI | Waenga - Teitei | Tere | Te Kaha Kuku me te Kaha Haehae |
| TDI | Tino Iti | Tino Tere | Whakakī Māmā i te Momo |
Ka tiakina e ngā rongoā kakara e rua ngā āhuatanga ātete wai o te HTPB. Ka tiakina tō elastomer whakamutunga mai i te mimiti wai, ngā waikawa waimeha, me ngā kawakore wai.
Tuhipoka: Ka pirau ngā wāhanga mārō kakara i raro i te mārama ultraviolet (UV) tika. Whakamahia te MDI me te TDI i ngā wāhi tanumia, pania, i roto rānei i te whare, ina iti noa te pānga o te UV.
IPDI me HDI mō ngā Hanganga Pūmau-Māmā
Ka whakatauhia e ngā isocyanate aliphatic ngā take koroheketanga wera me te pirau mārama. Ka ātete katoa a Isophorone diisocyanate (IPDI) me te hexamethylene diisocyanate (HDI) i ngā hihi UV. Ka ārai i te kōwhai me te ngatata o te mata i te wā roa e noho ana i waho.
E rua ngā rōpū NCO kāore i te rite ki te IPDI. Ka puhoi te tauhohe a te rōpū NCO tuatahi, engari ka tere ake te tauhohe a te rōpū NCO tuarua i raro i ngā pāmahana teitei. Ka taea e koe te whakamahi i tēnei rerekētanga nekeneke hei whakahaere i tō oranga-pot me te tukanga maka.
Ka whakaratohia e te HDI te ngāwari raina. Ka whakaitihia e tōna hanganga aliphatic ōrite ngā pāmahana wehenga moroiti, e pupuri ana i te ngāwari ki raro i ngā āhuatanga i raro i te kore.
- Ngā painga o te IPDI: He roa ake te ora o te kohua, he huringa whakamaroke ka taea te whakahaere, he pumau teitei i te pāmahana.
- Ngā painga o te HDI: He tino ngāwari ki te pāmahana iti, he ātete UV pai rawa atu, he iti ake te matotoru.
Mā te whakataurite i ngā Isocyanates ki ngā rapa wai tauhohe (HTPB me ngā aliphatic curatives ka puta he māramatanga whatu, he pumau tae, me ngā hiri ātete ki te huarere.
Te Hanganga Prepolymer me te Arotautanga Stoichiometry
Ka taea e te ranunga kotahi-pana tika te whakaputa i ngā tauhohenga wera kore whakahaere me te wehenga ā-wāhanga. Ka taea e koe te ārai i ēnei raruraru mā te hanga i tētahi Prepolymer kua whakamutua e te NCO tuatahi. Ka whakaitihia e te hanganga prepolymer te whakaputanga wera katoa i te wā o te whakamaroke whakamutunga, ā, ka whakaitihia hoki ngā tukunga monomer pūngoi.
- Te Whakarite Tauhohenga: Whakakīia tō tauhohenga ki te kapia HTPB maroke.
- Te Tango i te Makuku: Tangohia te hau o te kapia mā te korehau i te 90°C hei whakakore i te makuku e toe ana. Ka tauhohe te wai ki ngā rōpū NCO, ka puta he mirumiru hauhā me ngā ngoikore o te urea.
- Tāpiritanga Isocyanate: Tāpirihia te diisocyanate kua whiriwhiria e koe ki raro i te paraikete hauota maroke.
- Toronga Mekameka Whakahaeretia: Kia mau tonu te pāmahana i waenga i te 70°C me te 80°C kia tau ra ano te nui o te NCO.
Hipanga 1: Isocyanate Taikaha + HTPB ===> Prepolymer Kua Whakamutua e te NCO + Monomer Koreutu Hipanga 2: Prepolymer + Whakaroa Mekameka ===> Whatunga Polyurethane Kua Whakaorahia Me tino tatau koe i tō stoichiometry. Kia mau tonu te taupū NCO whānui (te ōwehenga ōrite o ngā rōpū NCO ki ngā rōpū OH) ki roto i te awhe 1.03 ki te 1.06.
$$\text{Taupū NCO} = \frac{\text{Ngā Taurite Katoa o te NCO}}{\text{Ngā Taurite Katoa o te OH}}$$
Ko te taupū NCO i raro iho i te 1.00 ka waiho hei mekameka HTPB kāore i tauhohe. Ka mahi ēnei ngota wai kāore i tauhohe hei mea hanga kirihou kāore e hiahiatia, ka whakaiti i tō modulus kume, ka whakaiti hoki i te ātete matū. I tetahi atu taha, ko te taupū NCO i runga ake i te 1.10 ka nui rawa te hononga whakawhiti. He nui rawa ngā hononga whakawhiti ka pakarukaru i raro i te kawenga pānga hihiri. Mā te stoichiometry tika ka tino pai te mahi.
Ngā Rautaki Kōwhiri CTBN, ATBN, me HTBN
Me whai rautaki whiriwhiri kua whakaritea mō ngā rōpū pito carboxyl, amine, me te hydroxyl i runga i ngā tuara rapa nitrile. Ka taea e koe te whakapai ake i te pakari o te pakaru, te ātete matū, me te mahi wera mā te hono i ēnei rapa mahi me ngā isocyanates tika.
Ngā Ranunga Epoxy-Polyurethane me te CTBN me te MDI
Kei roto i te carboxyl-terminated butadiene acrylonitrile (CTBN) ngā rōpū waikawa carboxylic whakamutunga (-COOH) me te tuara nitrile polar. Mā ngā tauhohenga tika i waenga i ngā waikawa carboxylic me ngā diisocyanates ka puta he hononga anhydride kore pumau, ka tukuna he hau waro hauhā. Ka taea e koe te whakakore i ngā mirumiru hau mā te hanga whatunga ranu epoxy-polyurethane.
CTBN + Resin Epoxy Taikaha ===> Prepolymer Rapa Kua Whakamutua ki te Epoxy Prepolymer Epoxy + 4,4'-MDI + Whakaroa Mekameka ===> Matrix Ranu Whakapakari Tuatahi, tauhohehia te CTBN ki te kapia epoxy nui rawa kia puta he takawaenga rapa kua oti te whakamutu ki te epoxy. Muri iho, tāpirihia te 4,4'-MDI me te whakaroa mekameka diol hei hanga i te tuara polyurethane kua honoa ki ngā rohe rapa.
Tohutohu Ngaio: Puritia te ihirangi acrylonitrile (AN) ki roto CTBN i waenga i te 18% me te 26%. Ka whakatairangahia e tēnei awhe AN motuhake te wehenga wāhanga i te wā e whakamaroke ana. Ka puta mai ngā rohe rapa iti rite ki te maikorona i te anga, ka hanga he ārai whai hua ki te horapa o te kapiti.
Ka whakaratohia e te MDI ngā wāhanga mārō kakara kaha e herea ana ki te matihiko porowhita. Ina pā te ahotea hihiri ki te ranu kua rongoatia, ka mimitihia e ēnei rohe CTBN marara te kaha pānga. Ka whiwhi koe i te pakari whati teitei me te kore e whakararu i te pumau miihini wera, te modulus kume rānei.
Te Hanganga Tika o te Amine-Isocyanate Urea me te ATBN
Kei roto i te amine-terminated butadiene acrylonitrile (ATBN) ngā rōpū mutunga amine tuatahi, tuarua rānei (-NH2, -NHR rānei). Ka tauhohe tonu ngā amine ki ngā diisocyanates i te pāmahana rūma. Ka hangaia e rātou he hononga polyurea pakari, kāore e hiahiatia he whakakorikori hangai.
| Inenga Mahi | Polyurethane (HTPB/MDI) | Polyurea (ATBN/MDI) |
|---|---|---|
| Tere o te Tauhohenga | Waenga (Meneti ki ngā Hāora) | Tino Tere (Hekona ki te Miniti) |
| Tepe Wera | 100°C - 120°C | 150°C - 180°C |
| Te Hononga Hauwai | Ngā Here Urea/Urethane Kotahi | Ngā Here Urea Bidentate Matotoru |
| Te aro ki te makuku | Teitei (Mōrearea hanga hau) | Iti (Ka hinga te Amine i te wai) |
Ina Whakatauritehia ngā Isocyanates ki ngā Rapa Wai Tauhohe (Ngā pūnaha HTPB, ngā pūnaha ATBN rānei), me whakarerekē e koe ō taputapu whakaranu kia taea ai te whakahaere i ēnei rerekētanga nekeneke. He tere rawa te tauhohenga a te ATBN, me whakamahi koe i ngā pane whakaranu pēhanga teitei motuhake.
ATBN (Ngā Mutunga Amine) + Isocyanate (NCO) ===> Ngā Wāhanga Mārō Polyurea (Te Herenga Bidentate) Ka hangaia e ngā rohe mārō polyurea te hononga hauwai bidentate kaha. Mā ēnei hononga whakawhiti ā-tinana ka ara ake te pūwāhi pirau wera o tō elastomer ki runga ake i te 150°C. Ka whakakorea hoki e koe ngā raruraru aro ki te makuku i te wā tukatuka. He tere ake te tauhohenga o ngā rōpū mutunga amine ki te NCO i te wai taiao.
Te Hototahitanga HTBN i roto i ngā Pūnaha Ātete-Wai
Te akirironitirīni butadiene kua whakamutua ki te hauwai-kōpū (HTBN) Ka whakakotahi i te mahi hydroxyl (-OH) me te tuara nitrile polar. Ka tere te pakaru o ngā rapa kore-polar ina pāngia e ngā wahie kore-polar, ngā whakarewa kakara, ngā wai waipēhi rānei. Ka panaia e ngā rōpū acrylonitrile polar i roto i te HTBN ngā hauwaiwai, ka tiaki i tō elastomer mai i te pupuhi o te whakarewa.
HTBN (Tuarai Pōro) + IPDI/MDI ===> Ārai Waro-Ātete Wahie Me taurite te HTBN ki ngā diisocyanate hototahi hei hanga hiri pakari, gaskets, me ngā arai tāke wahie:
- Tāruatia te HTBN me te MDI: Ka tutuki i a koe te pakari ā-mīhini mōrahi, te ātete teitei ki te haehae, me te kaha matomato tere mō ngā gaskets ahumahi.
- Tāruatia te HTBN ki te IPDI: Ka whiwhi koe i ngā paninga tāke wahie ngāwari, pumau ki te UV, ā, e ātete ana ki te pakaru i raro i ngā nekehanga pāmahana hihiri.
Ka taea e koe te whakarerekē i te nui o te nitrile i roto i te HTBN hei whakatikatika i te ātete whakarewa. Ko ngā taumata acrylonitrile teitei ake ka whakanui ake i te polarity me te ātete wahie. Heoi, ko te polarity teitei ake ka whakanui ake i te matotoru o te kapia tuatahi. Me whakamahana e koe te HTBN ki te 50°C i te wā e tango ana i te hau hei whakaiti i te matotoru tukatuka i mua i te whakauru i tō diisocyanate whiriwhiri.
Ngā Tawhā Whakatakoto me te Tukatuka Tino Hira
Ngā Tauwehenga Stoichiometric me te Mana Whakahaere Taupū NCO
Me tino whakahaere e koe te ōwehenga stoichiometric i waenga i ngā rōpū isocyanate hohe me ngā rōpū mutunga rapa. Me whai i te taupū NCO i waenga i te 1.02 me te 1.08 kia tino honoa ai te matū. Mēnā he taupū kei raro iho i te 1.00 ka waiho ngā oligomer kāore i tauhohe. Ka mahi ēnei ngota kore utu hei mea hanga kirihou kāore e hiahiatia, ā, ka whakaiti i te hanganga pai. I tetahi atu taha, mēnā he taupū kei runga ake i te 1.10 ka nui rawa te honoa, ka pakarukaru ai tō elastomer kua rongoatia.
Te Āhua o te Rohe me te Wehenga o te Āhuatanga Moroiti
Ko te wehenga ā-moroiti te mea e whakahaere tika ana i te mahi ā-pūkaha o tō matrix polymer kua whakamaroketia. Ko ngā tuara rapa kore-pororaru ka pana noa i ngā wāhanga mārō urethane pororaru, urea rānei. Ka taea e koe te whakarite i tēnei kore hototahi matū hei akiaki i te huihuinga-ā-unoa i te wā e whakamaroketia ana. Ko ngā rohe mārō kua mararahia he hononga ā-tinana hei whakanui ake i te kaha kume. I taua wā, ka tiakina e ngā rohe ngohengohe rapa tonu te ngāwari o te pāmahana iti me te mimiti i te kaha pānga hihiri.
Te Matatini Tukatuka me te Arotautanga o te Ora-Pot
Ina whakatauritea ngā Isocyanates ki ngā rapa wai tauhohe (ngā hanganga HTPB, he maha ngā wā ka nui te matotoru tīmatanga ka aukati i te whakakī me te tango hau whai hua i roto i te pokepokea aiKa whakaitihia e ngā whakarewa kore-tauhohe te matotoru, engari ka hangaia he āputa ngoikore i te wā e mimiti ana. Engari, ka mahi te HTPB taumaha ngota tino iti hei waimeha tauhohe i roto i ngā hanganga polymer, e āhei ai te whakaiti i te matotoru me te tiaki i ngā āhuatanga matua o te rauemi.
Tohutohu: Whakawerahia tō rapa wai ki te 50°C i mua i te tāpiri i te rongoā hei whakaroa i te ora o te kohua me te tere ake o te tukunga o ngā mirumiru.
- Tātaitia te HTPB kore-polar ki te MDI, ki te TDI rānei hei whakanui ake i te wai-aroha me te ngāwari ki te pāmahana iti, engari he iti te utu.
- Honoa te HTPB ki te aliphatic IPDI, HDI rānei mō te ātete UV pai rawa atu, me te roa ake o te ora o te pahū.
- Whakamahia ngā rapa nitrile (CTBN, ATBN, HTBN) i roto i ngā pūnaha porowhita hei whakanui i te pakari o te pakaru me te ātete ki te hinu.
- Whakahaerehia te stoichiometry NCO kia tino tika. Mā ngā ōwehenga tika ka ārai i te ngoikore o tō elastomer e ngā oligomer kāore i tauhohe.
Ngā Pātai Auau
Me pēhea te whiriwhiri i waenga i te MDI me te IPDI mō ngā pūnaha HTPB?
Tohutohu Tere: Tātaitia tō rongoā ki te taiao tono.
Kōwhiria te MDI ina hiahia koe ki te kaha kume teitei me te utu iti mō ngā tono o roto. Kōwhiria te IPDI mō ngā hanganga o waho e hiahia ana ki te pumau UV me te roa o te ora o te kohua.
He aha me pupuri ai e koe te taupū NCO i waenga i te 1.02 me te 1.08?
Mā tēnei ōwehenga motuhake ka tino honoa te matū. Ka ārai i te rapa wai kāore i tauhohe kia whakangawari i tō hanganga, ā, ka ārai i te nui o te hononga kia kore ai e hanga he elastomer pakarukaru.
Me pēhea te whakapai ake a CTBN i te pakari o te pakaru i roto i ngā ranu epoxy-polyurethane?
Ka tau te CTBN ki roto i ngā wāhi rapa ririki i te wā e whakamaroke ana. Ka mimitihia e ēnei matūriki rapa moroiti te kaha pānga, ā, ka aukati i te horapa o te kapiti puta noa i tō hanganga pūmua kua whakamarokehia.