Ngā Tauira Pātai e Matapaki ana i te Whakapūhuitanga Whakatōtō
Ko te whakapūhuitanga kondensasi he momo tauhohenga whakapūhuitanga e whakaputa ana i ngā pūhuitanga mā te hono i ngā monomer mā te tango i ngā ngota iti, pērā i te wai, te methanol, te HCl rānei. He mahi nui tā tēnei tukanga i roto i te hanganga o ngā rauemi pūhuitanga e whakamahia ana i ia rā. I roto i tēnei tuhinga, ka tūhuratia e mātou ngā tauira me te matapaki i te whakapūhuitanga kondensasi hei whakahōhonu ake i tō mātou māramatanga ki tēnei ariā.
He Kupu Whakataki ki te Whakapūhui Whakapūngao
I mua i te ruku hohonu ki ngā pātai, me titiro matatau tātou ki te whakapūhuitanga o te konupūnga. Ko te whakapūhuitanga o te konupūnga te tukanga hanganga o te pūhui mā te tauhohenga o ngā monomer e rua, neke atu rānei, kei roto ngā rōpū mahi, ko te tikanga me te whakakorenga o ngā ngota iti pēnei i te wai hei hua taha. He nui ake te taumaha ngota o te pūhui ka puta i ngā monomer. Ko ngā tauira noa o te whakapūhuitanga o te konupūnga ko te hanganga o ngā polyesters me ngā polyamides.
Ngā Tauira o ngā Pūmua mai i te Pūmuatanga Whakapūtātanga
1. Polyester: I hangaia mai i te tauhohenga o te waikawa terephthalic (benzene-dicarboxylate) me te ethylene glycol. Hei tauira hua: PET (polyethylene terephthalate).
2. Polyamide (Nailona): I hangaia mai i te tauhohenga o te waikawa adipic me te hexamethylene diamine. Tauira hua: Nailona-66.
3. Polycarbonate: I hangaia mai i te tauhohenga i waenga i te bisphenol A me te phosgene.
Ngā Tauira Pātai e Matapaki ana i te Whakapūhuitanga Whakatōtō
Kei raro nei ētahi tauira pātai me ngā kōrero hei āwhina i a koe ki te mārama ki te tukanga whakapūhui konupūmā.
Pātai 1: Te Hanganga o te Polyester
Pātai: Whakamāramahia te tauhohenga e hanga ai te polyester mai i te ethylene glycol me te waikawa terephthalic. Tuhia te hanganga o te polymer ka puta mai, ka tatau i te papatipu ngota whanaunga o te wāhanga iti rawa o te polymer.
Kōrero:
Ka hangaia te polyester mā te tauhohenga whakapūpū i waenga i te ethylene glycol (CH₂OH-CH₂OH) me te waikawa terephthalic (C₆H₄(COOH)₂).
Ka taea te tuhi i tēnei tauhohenga hanganga penei:
\[ n \, (\kuputuhi{CH}_2\kuputuhi{OH-CH}_2\kuputuhi{OH}) + n \, (\kuputuhi{C}_6\kuputuhi{H}_4(\kuputuhi{COOH})_2) \rightarrow (\kuputuhi{O}-\kuputuhi{C}_6\kuputuhi{H}_4-\kuputuhi{COO}-\kuputuhi{CH}_2-\kuputuhi{CH}_2-\kuputuhi{O})_n + 2n\, \kuputuhi{H}_2\kuputuhi{O} \]
Ko te hanganga o tēnei polyester ka puta he wai hei hua taha. Hei whakatau i te hanganga taketake o te polyester, me titiro tātou ki te wāhanga e tāruarua ana o te mekameka polymer:
Hanganga taketake o te PET (Polyethylene Terephthalate):
\[
\kuputuhi{-O-}\kuputuhi{C}_6\kuputuhi{H}_4\kuputuhi{-COO-CH}_2\kuputuhi{-CH}_2\kuputuhi{-}
\]
Ka taea te tatau i te papatipu ngota whanaunga o te waeine iti rawa o te polyester penei:
– Papatipu ngota o te -CH₂-CH₂-O- (ethylene glycol kāore he H₂O): 60 g/mol
– Papatipu ngota o te -COO- (rōpū ester): 44 g/mol
– Papatipu ngota o te C₆H₄ (benzene kāore he H₂O): 76 g/mol
Te tapeke o ngā papatipu ngota o ngā wāhanga iti rawa:
\[
60 + 44 + 76 = 180 karamu/mol
\]
Pātai 2: Te Hanganga o te Polyamide (Nailona-6,6)
Pātai: Whakamāramahia te tukanga hanga i te Nylon-6,6 mā te tauhohenga whakapūhui o te waikawa adipic me te hexamethylene diamine. Whakauruhia te hanganga wae taketake o te Nylon-6,6, me te tatau i te papatipu ngota whanaunga o te wae iti rawa.
Kōrero:
Ka hangaia te nairon-6,6 mai i te tauhohenga whakapūpū i waenga i te waikawa adipic (HOOC-(CH₂)₄-COOH) me te hexamethylene diamine (H₂N-(CH₂)₆-NH₂).
Ko te tauhohenga hanganga ko:
\[ n \, (\text{HOOC-(CH}_2\text{)}_4\text{ -COOH}) + n \, (\text{H}_2\text{N-(CH}_2\text{)}_6\text{ -NH}_2) \rightarrow (\text{-NH-(CH}_2\text{)}_6\text{-NH\text_(CH}}_2\text{-NH\text_(CH}}_2}} 2n \, \text{H}_4\text{O} \]
Hanganga taketake o te Nairon-6,6:
\[
\kuputuhi{-NH-(CH}_2\kuputuhi{)}_6\kuputuhi{-NH-CO-(CH}_2\kuputuhi{)}_4\kuputuhi{-CO-}
\]
Papatipu ngota whanaunga o te waeine iti rawa:
– Papatipu ngota o te -NH-(CH₂)₆-NH- (hexamethylene diamine tangohia te H₂O): 114 g/mol
– Papatipu ngota o te -CO-(CH₂)₄-CO- (waikawa adipic kāore he H₂O): 142 g/mol
Te tapeke o ngā papatipu ngota o ngā wāhanga iti rawa:
\[
114 + 142 = 256 karamu/mol
\]
Pātai 3: Polycarbonate
Pātai: Me pēhea te tauhohenga o te bisphenol A me te phosgene e hanga ai i te polycarbonate? Tuhia te hanganga taketake o te polycarbonate, ka tatau i te papatipu ngota whanaunga o te waeine iti rawa.
Kōrero:
Ka hangaia te polycarbonate mā te tauhohenga i waenga i te bisphenol A (C₁₅H₁₆O₂) me te phosgene (COCl₂).
Ka taea te tuhi i te tauhohenga hanganga penei:
n + 2n \, \text{HCl} \]
Hanganga taketake o te Polycarbonate:
\[
\text{-O-CO-OC}_6\text{H}_4\text{C}(\text{CH}_3)_2\text{C}_6\text{H}_4\text{O}-
\]
Papatipu ngota whanaunga o te waeine iti rawa:
– Papatipu ngota o te C₆H₄-C(CH₃)₂-C₆H₄ (bisphenol A kāore he H₂O): 224 g/mol
– Papatipu ngota o te -COO-: 28 g/mol
Te tapeke o ngā papatipu ngota o ngā wāhanga iti rawa:
\[
224 + 28 = 252 karamu/mol
\]
Whakamutunga
I roto i tēnei tuhinga, kua matapakihia e mātou te ariā o te whakapūhuitanga konupūmā, e kapi ana i ngā tauhohenga taketake me ngā hanganga o ētahi pūhui rongonui i hangaia e tēnei tukanga. Mā te whakarato tauira me ngā matapakinga, ko te whāinga o tēnei tuhinga he whakamārama i te mahi a ēnei tauhohenga me te pehea e taea ai e tātou te tatau i ngā papatipu ngota whanaunga o ngā waeine iti rawa i roto i te mekameka pūhui. He mea nui te māramatanga pai ki te whakapūhuitanga konupūmā nā te mea he whānuitia te whakamahinga o tēnei tukanga i roto i te ahumahi hei hanga i ngā momo rauemi me ngā āhuatanga ahurei me te whānuitanga o ngā tono.
