Nā nīnau hoʻohālike a me ke kūkākūkā ʻana no ka Polymer
I. Hoʻolauna
He mau hui kemika nā polymers me nā ʻano molekala nui i haku ʻia me nā ʻāpana liʻiliʻi e hana hou ʻia ana i kapa ʻia ʻo monomers. Hiki ke loaʻa nā polymers ma nā ʻano like ʻole a hoʻohana ʻia i nā ʻano he nui o ke ola o kēlā me kēia lā, mai nā plastics a me ka rubber a hiki i nā protein a me ka DNA i loko o ke kino o ke kanaka. Ma kēia ʻatikala, e ʻimi mākou i kekahi mau pilikia hoʻohālike e pili ana i nā polymers a hāʻawi i nā hoʻonā no kēlā me kēia pilikia e kōkua i ka hoʻomaopopo ʻana i kēia manaʻo paʻakikī.
II. Nā Manaʻo Kumu o nā Polymers
Ma mua o ko mākou komo ʻana i ke kūkākūkā ʻana i nā nīnau, aia kekahi mau manaʻo nui e pono e hoʻomaopopo ʻia:
1. Monomers a me Polymerization: ʻO nā Monomers nā ʻāpana kumu e hana ai i nā polymers ma o ke kaʻina hana polymerization. ʻElua ʻano nui o ka polymerization: ka hoʻohui a me ka condensation.
2. ʻAno Polymer: Hiki i nā Polymers ke linear, lālā, a i ʻole crosslinked.
3. Nā ʻAno Polymers: Thermoplastics, thermosets, a me elastomers, nona kēlā me kēia ʻano he ʻokoʻa nā waiwai kino a me ka thermal.
III. Nā Nīnau Hoʻohālike a me ke Kūkākūkā ʻana
Nīnau 1: E wehewehe i ka ʻokoʻa ma waena o ka hoʻohui a me ka polymerization condensation, a hāʻawi i hoʻokahi laʻana o kēlā me kēia.
Kūkākūkā:
– Hoʻohui polymerization: He hana kahi e hoʻopili ai nā monomers e loaʻa ana nā pilina pālua me kekahi me ka ʻole o ka hoʻokumu ʻia ʻana o kahi mole liʻiliʻi. ʻO kahi laʻana ka hoʻokumu ʻia ʻana o ka polyethylene mai nā monomers ethylene.
– Condensation polymerization: He hana e hoʻopili ai nā monomers ma ka wehe ʻana i kahi mole liʻiliʻi e like me ka wai a i ʻole methanol. ʻO kahi laʻana o ka condensation polymerization ka hoʻokumu ʻia ʻana o ka nylon mai ka adipic acid a me ka hexamethylenediamine, kahi i wehe ʻia ai ka wai i ka mole liʻiliʻi.
Nīnau 2: He aha nā polymers thermoplastic a me thermoset? E hāʻawi i nā laʻana.
Kūkākūkā:
– Nā polymers Thermoplastic: Nā polymers e palupalu i ka wā e hoʻomehana ʻia ai a paʻakikī i ka wā e hoʻomaʻalili ʻia ai. ʻAe kēia iā lākou e hoʻololi hou ʻia i nā manawa he nui. ʻO nā laʻana e komo pū me ka polyethylene, polystyrene, a me PVC.
– Nā polymers Thermosetting: ʻAʻole hiki ke hoʻoheheʻe hou ʻia nā polymers, ke hana ʻia,. ʻO kēia ma muli o ke alo o nā pilina cross-linked mau loa. ʻO nā laʻana e komo pū me Bakelite a me epoxy.
Nīnau 3: Loaʻa i kahi polymer kahi kaulahao kalapona nui pololei me nā mea pani atom chlorine ma kēlā me kēia kaulahao kalapona ʻelua. E ʻike i ka polymer a wehewehe pehea e hoʻohālikelike ai kona mau waiwai kino me nā mea o ka polyethylene.
Kūkākūkā:
ʻO ka polymer i wehewehe ʻia ʻo polyvinyl chloride (PVC). Hana ʻia ʻo PVC mai ka vinyl chloride, a ʻo nā mea pani chlorine e hoʻolilo iā ia i ʻoi aku ka paʻa a ʻoi aku ke kūpaʻa i nā aila a me nā kemika ma mua o ka polyethylene. ʻOi aku ka paʻa o ka PVC i ke ahi a ʻoi aku ke kaumaha ma mua o ka polyethylene ma muli o nā ʻātoma chlorine kaumaha.
Nīnau 4: Hiki i nā polymers kūlohelohe e like me ka laholio (elastomers) ke hana ʻia i ka vulcanization. E wehewehe i ke kaʻina hana vulcanization a me kona hopena i nā waiwai kino o ka laholio.
Kūkākūkā:
ʻO ka Vulcanization ke kaʻina hana o ka hoʻomehana ʻana i ka laholio me ka sulfur. Hoʻokumu kēia i nā loulou kea ma waena o nā kaulahao polymer, e hoʻolilo ana i ka laholio i ʻoi aku ka elastic, ikaika, a kūpaʻa i nā loli o ka mahana. Hoʻonui kēia kaʻina hana i ke kūpaʻa i ka abrasion a me ka ʻaʻahu, e hoʻolilo ana i ka laholio i ʻoi aku ka paʻa no nā noi ʻoihana e like me nā kaila kaʻa.
Nīnau 5: E helu i ka helu o nā ʻāpana hana hou (kekelē o ka polymerization) no ka polyethylene me ka awelika o ke kaumaha molekala o 28.000 g/mol. ʻO ka nuipa molekala o ka ethylene monomer he 28 g/mol.
Kūkākūkā:
Hiki ke helu ʻia ke kekelē o ka polymerization (n) me ka hoʻohana ʻana i ke ʻano hana:
\[ n = \frac{\text{Kaumaha molekala o ka polymer}}{\text{Kaumaha molekala o ka monomer}} \]
\[ n = \frac{28000 \, \text{g/mol}}{28 \, \text{g/mol}} = 1000 \]
No laila, aia ma kahi o 1000 mau ʻāpana hana hou i ka polymer.
IV. Hopena
Hiki i nā kūkākūkā e pili ana i nā polymers ke uhi i nā kumuhana like ʻole, mai ko lākou ʻano kumu a me nā ʻano a hiki i ko lākou mau waiwai kino a me ke kemika a me nā noi i ke ola o kēlā me kēia lā. Ma o nā nīnau a me nā kūkākūkā ʻana, hiki ke hoʻoholo ʻia he mau mea kemika paʻakikī nā polymers e pāʻani ana i kahi kuleana koʻikoʻi i nā ʻoihana like ʻole a me ka biology. Me ka hoʻomaopopo hohonu ʻana i ko lākou mau waiwai a me nā kaʻina hana hoʻokumu, hiki iā mākou ke hoʻomaopopo maikaʻi pehea e hoʻomaikaʻi ai i kā lākou hoʻohana ʻana i nā noi ʻenehana a me nā ʻepekema like ʻole. Ke hoʻomau nei nā Polymers i kahi wahi noiʻi ikaika no ka hoʻomohala ʻana i nā mea ʻoi aku ka maikaʻi a me ka launa pū ʻana me ke kaiapuni.
