Qhov sib txawv tseem ceeb ntawm atactic isotactic thiab syndiotactic polymers yog tias atactic polymers muaj lawv cov neeg hloov pauv hauv ib qho random thiab isotactic polymers muaj lawv cov neeg hloov pauv nyob rau hauv tib sab, whereas cov syndiotactic polymers muaj lawv cov hloov pauv hauv cov qauv sib txawv.
Tacticity yog ib lub tswv yim tshuaj uas piav qhia txog tus txheeb ze stoichiometry ntawm cov chaw chiral uas nyob ib sab hauv macromolecule. Ib tug macromolecule yog ib tug loj molecule xws li ib tug polymer. Tacticity yog qhov tseem ceeb hauv kev txiav txim siab cov khoom ntawm polymer. Nws yog vim hais tias cov qauv ntawm cov polymer tswj lwm yam khoom xws li rigidity, crystallinity, thiab lwm yam.
Dab tsi yog Atactic Polymer?
Ib qho atactic polymer yog cov khoom siv polymer uas cov khoom hloov pauv hauv cov saw hlau tau teeb tsa hauv qhov sib txawv. Feem ntau, cov polymers uas tsim los ntawm cov dawb radical polymerization muaj cov qauv no; Piv txwv li, polyvinyl chloride. Atactic polymers muaj cov qauv amorphous vim yog kev sib koom ua ke ntawm cov pab pawg hloov pauv.
Daim duab 01: Cov qauv dav dav ntawm Atactic Polymer
Txawm li cas los xij, cov khoom siv hluav taws xob no tseem ceeb hauv cov cuab yeej siv hluav taws xob, xws li. polystyrene. Txawm hais tias nws yog atactic, peb tuaj yeem tau txais cov khoom siv syndiotactic polystyrene yog tias peb siv cov catalyst tshwj xeeb. Txawm li cas los xij, kev lag luam tsim polystyrene yog atactic vim manufacturers tsis siv cov catalysts. Txij li thaum muaj cov pab pawg sib txawv ntawm qhov sib txawv, cov saw hlau polymer tsis tuaj yeem teem caij raws li kev txiav txim. Yog li ntawd, polystyrene yog cov khoom siv semi-crystalline.
Thaum xav txog cov qauv ntawm cov khoom siv polymer, peb hu ob lub polymer uas nyob ib sab ua "diad". Yog hais tias lub diad muaj ob qhov sib npaug, taw qhia tib yam, peb hu nws ua meso diad. Hauv atactic polymers, qhov feem pua ntawm cov meso diads no txawv ntawm 1-99%.
YIsotactic Polymer yog dab tsi?
Isotactic polymer yog ib qho polymer uas muaj cov khoom hloov pauv ntawm tib sab ntawm cov saw hlau. Qhov ntawd txhais tau tias; Txhua qhov hloov pauv ntawm cov khoom siv polymer yog nyob ntawm tib sab ntawm lub nraub qaum ntawm cov polymer.
Daim duab 02: Cov qauv ntawm Isotactic Polymer
Piv txwv li, kev lag luam npaj polypropylene yog isotactic. Nws txoj kev tsim khoom yog Ziegler-Natta catalysis. Feem ntau, cov polymers no yog semi-crystalline. Lawv qhia ib tug helix configuration. Tsis tas li, cov khoom no muaj 100% meso diads.
YDab tsi yog Syndiotactic Polymer?
Syndiotactic polymers yog cov khoom siv polymer uas muaj cov khoom hloov pauv hauv cov qauv sib txawv. Yog li ntawd, cov pab pawg hloov pauv muaj lwm txoj haujlwm raws li tus txha caj qaum ntawm cov polymer.
Daim duab 03: Cov qauv ntawm Syndiotactic Polymer
Yog tias peb tsim cov polystyrene ntawm metallocene catalysis polymerization, nws muab cov khoom siv polystyrene syndiotactic thiab nws yog cov khoom siv crystalline. Cov polymer muaj 100% racemo diads (diad muaj ob chav nyob rau hauv kev tawm tsam).
Qhov txawv ntawm Atactic Isotactic thiab Syndiotactic Polymer yog dab tsi?
Muaj peb hom polymers raws li kev sib tw: atactic polymers, isotactic polymers, thiab syndiotactic polymers. Qhov sib txawv tseem ceeb ntawm atactic isotactic thiab syndiotactic polymers yog tias atactic polymers muaj lawv cov neeg hloov pauv hauv ib qho random thiab isotactic polymers muaj lawv cov neeg hloov pauv nyob rau tib sab, hos cov syndiotactic polymers muaj lawv cov hloov pauv hauv cov qauv sib txawv.
Ntxiv mus, atactic polymers feem ntau yog amorphous thiab isotactic polymers yog semi-crystalline, whereas syndiotactic polymers feem ntau yog crystalline. Tsis tas li ntawd, lwm qhov sib txawv tseem ceeb ntawm atactic isotactic thiab syndiotactic polymers yog atactic polymers muaj 1-99% meso diads thaum isotactic polymers muaj 100% meso diads thiab syndiotactic polymers muaj 100% racemo diads.
Cov hauv qab no qhia txog qhov sib txawv ntawm atactic isotactic thiab syndiotactic polymer, ib sab.
Summary – Atactic Isotactic vs Syndiotactic Polymer
Muaj peb hom polymers raws li lawv cov tacticity: atactic polymer, isotactic polymer, thiab syndiotactic polymer. Qhov sib txawv tseem ceeb ntawm atactic isotactic thiab syndiotactic polymer yog qhov atactic polymers muaj lawv cov neeg hloov pauv hauv qhov sib txawv thiab cov isotactic polymers muaj lawv cov neeg hloov pauv nyob rau tib sab, hos cov syndiotactic polymers muaj lawv cov hloov pauv hauv cov qauv sib txawv.
