Ngā Tauira Pātai me te Kōrero mō te Whakamāramatanga me te Hanganga o ngā Polymers
Ko ngā pūmua he matū rauropi nui e titoa ana i ngā waeine e mōhiotia ana ko ngā monomer. I roto i te matū, he mahi nui tā ngā pūmua i roto i te whānuitanga o ngā tono, mai i ngā ahumahi kirihou me te kakahu ki te rongoā koiora. Ka matapakihia e tēnei tuhinga te whakamāramatanga o ngā pūmua me tōna hanganga, me te whakarato hoki i ētahi tauira raruraru me ngā otinga hei whakahōhonu ake i tō tātou māramatanga ki tēnei ariā.
Te Mārama ki ngā Pūmua
I ahu mai te kupu polymer i ngā kupu "poly," arā, he maha, me te "mer," arā, he wāhanga, he wae rānei. Nō reira, ko te polymer he ngota nui i hangaia mai i ngā wae iti maha e kiia nei ko ngā monomer. Ka honoa ēnei monomer mā roto i ngā tauhohenga polymerization hei hanga i ngā hanganga mekameka roa.
Ngā Tauira o ngā Pūmua Taiao me ngā Pūmua Hanga:
1. Ngā Pūmua Taiao:
– Cellulose: He mea tito mai i ngā monomer glucose i roto i ngā pakitara pūtau tipu.
– Pūmua: He mea tito mai i ngā waikawa amino hei monomer.
– Rapa māori: He mea hanga mai i te pūmua isoprene.
2. Ngā Pūmua Hanga:
– Polyethylene (PE): Whakamahia hei hanga putea kirihou.
– Polypropylene (PP): Whakamahia i roto i ngā ipu kirihou me ngā taonga o te whare.
– Polyvinyl chloride (PVC): Rauemi mō ngā paipa me ngā taputapu hauora.
Hanganga Pūmua
I runga i te hanganga, ka taea te wehewehe i ngā pūmua ki ētahi momo i runga i tō rātou āhua me te whakaritenga mekameka. Ko ngā momo hanganga pūmua ēnei:
1. Hanganga Raina:
– Ko ngā pūmua he hanganga rārangi, he mekameka roa, he tika hoki o ngā monomer e hono tahi ana. Ko ētahi tauira ko te polyethylene me te polystyrene.
2. Hanganga Peka:
– He mekameka matua tō ngā pūmua peka, ā, he poto ngā peka e puta mai ana i te mekameka matua. Hei tauira, ko te polypropylene peka.
3. Hanganga Whatunga (Hononga-whakawhiti):
– He mekameka kei roto i ēnei pūmua e hono tahi ana hei hanga i tētahi whatunga toru-ahu. Ko ētahi tauira ko te kapia epoxy me te bakelite.
4. Hanganga Poraka Copolymer:
– E rua, neke atu rānei ngā momo monomer e whakaritea ana i roto i te āhua raupapa, ā, e hanga ana i ngā poraka motuhake i te mekameka polymer. Hei tauira, ko te SBS (styrene-butadiene-styrene).
Ngā Pātai Tauira me te Kōrero
Hei mārama ake ki te tikanga me te hanganga o ngā pūmua, anei ētahi tauira pātai me ā rātou matapakinga.
Pātai 1:
Pātai: Whakahuatia ngā rerekētanga matua e toru i waenga i ngā pūmua thermoplastic me ngā pūmua thermoset!
Kōrero:
– Kirihou wera:
– Ka rewa ina werahia, ā, ka whakapakeke ina whakamataohia, ka taea te mahi i tēnei mahi i ngā wā maha.
– He rārangi, he paku peka rānei te hanganga ngota ngota.
– Ngā Tauira: Polyethylene (PE), Polypropylene (PP).
– Te whakamahana:
– Ka pāngia e ngā huringa matū kore e taea te hoki anō ina werahia, ka whakapakeketia i te weranga tuatahi, engari kāore e taea te rewa anō.
– He hanganga whatunga toru-ahu tōna e kore e taea te whakarerekē.
– Ngā Tauira: Te kapia epoxy, te bakelite.
Pātai 2:
Pātai: Me pēhea te whakatau i te taumaha ngota toharite (Mn) me te taumaha taumaha ngota toharite (Mw) o tētahi pūmua?
Kōrero:
– Tau Taumaha Ngota Toharite (Mn):
– Mn = Σ(Ni Mi) / ΣNi
– Ko Ni te maha o ngā ngota ngota me te taumaha ngota ngota ko Mi.
– Taumaha Taumaha Ngota Toharite (Mw):
– Mw = Σ(Ni Mi^2) / Σ(Ni Mi)
– Ka nui ake te taumaha o ngā ngota ngota he nui ake te taumaha ngota, ā, he nui ake i te Mn te taumaha ngota.
Pātai 3:
Pātai: Whakatauhia te momo pūmua mai i te kōrero e whai ake nei: "He hanganga taketake tō tēnei pūmua kei roto ko ngā waeine etirene e tāruarua ana, ā, he ngāwari ake ōna āhuatanga."
Kōrero:
– I runga i te kōrero e titoa ana te pūmua i ngā waeine etilena e tāruarua ana, ā, he āhua ngāwari, ko te pūmua he Polyethylene (PE).
Pātai 4:
Pātai: Whakamāramahia ngā tukanga o te whakakotahitanga tāpiri me te whakakotahitanga whakapūpū mā te hoatu tauira mō ia tukanga.
Kōrero:
– Te Whakapūhuitanga Tāpiri:
– Ko te tukanga e honoa ai ngā monomer me ngā hononga takirua (hei tauira, ngā alkene) ki a rātou anō, me te kore e puta he hua taha.
– Tauira: Polyethylene mai i te ethylene.
– n(C2H4) → [-CH2-CH2-]n
– Te Whakapūhuitanga o te Whakapūngao:
– He tukanga e tauhohe ai ngā monomer e rua, neke atu rānei, me ngā rōpū mahi rerekē e rua, ka hanga he pūmua, ka puta he hua taha pērā i te wai, te methanol rānei.
– Tauira: Nylon-6,6 mai i te hexamethylenediamine me te waikawa adipic.
– H2N-(CH2)6-NH2 + HOOC-(CH2)4-COOH → [-NH-(CH2)6-NH-CO-(CH2)4-CO-]n + 2nH2O
Pātai 5:
Pātai: He aha te tikanga o te regiospecificity i roto i te polymerization, ā, he aha tōna pānga ki te hanganga o te polymer?
Kōrero:
– Te motuhaketanga ā-rohe:
– Ko te regiospecificity e pā ana ki te auau o te hononga o ngā monomer ki roto i te mekameka, e whakatau ana i te whakatakotoranga o ngā hononga matū.
– Ka taea e ngā pūmua te whai hanganga isotactic (kei te taha kotahi o te mekameka ngā whakakapinga katoa), syndiotactic (ka taupatupatu ngā whakakapinga i te tūranga), atactic rānei (ka tohatoha matapōkeretia ngā whakakapinga).
– Tauira: Ka taea te hanga i te polypropylene hei isotactic PP, syndiotactic PP, atactic PP rānei, ā, ka pā tēnei ki ōna āhuatanga ā-tinana, pērā i te tioata me te ira rewa.
Whakamutunga
He whānuitia ngā hanganga me ngā āhuatanga o ngā pūmua, i runga i te momo monomer me te āhua o tō rātou whakaritenga i roto i te mekameka pūmua. Ko te mārama ki te hanganga me te hanganga o ngā pūmua, me te āhua o tō rātou hanganga, he mea nui ki ā rātou tono i roto i te ahumahi me te hangarau. Ka āwhina hoki ngā mahi me ngā kōrero kua whakaratohia ki te whakapakari i ngā ariā matua nui i roto i te matū pūmua. Mā te mārama pai, ka taea e tātou te whakamahi i ngā pūmua i roto i ngā momo tono auaha ā muri ake nei.
