YPolyester vs Polyamide
Polymers yog cov molecules loj, thiab muaj tib lub qauv tsim rov ua dua. Cov units rov ua dua yog hu ua monomers. Cov monomers no yog sib koom ua ke nrog covalent bonds los tsim ib lub polymer. Lawv muaj qhov hnyav molecular thiab muaj ntau dua 10,000 atoms. Nyob rau hauv cov txheej txheem synthesis, uas yog hu ua polymerization, ntev polymer chains tau txais. Muaj ob lub ntsiab ntawm cov polymers nyob ntawm lawv cov txheej txheem synthesis. Yog hais tias cov monomers muaj ob daim ntawv cog lus ntawm carbons, polymers tuaj yeem ua ke los ntawm kev sib txuas ntxiv. Cov polymers no hu ua ntxiv polymers. Hauv qee qhov kev cuam tshuam polymerization, thaum ob lub monomers koom nrog, ib qho me me zoo li dej raug tshem tawm. Xws li cov polymers yog condensation polymers. Polymers muaj qhov sib txawv ntawm lub cev thiab tshuaj lom neeg ntau dua li lawv cov monomer. Ntxiv mus, raws li tus naj npawb ntawm rov qab units hauv cov polymer, nws cov khoom sib txawv. Muaj ntau cov polymers tam sim no nyob rau hauv ib puag ncig ntuj, thiab lawv ua lub luag haujlwm tseem ceeb heev. Synthetic polymers kuj tau siv dav rau ntau lub hom phiaj. Polyethylene, polypropylene, PVC, nylon, thiab Bakelite yog ib co ntawm cov hluavtaws polymers. Thaum tsim cov khoom siv hluavtaws, cov txheej txheem yuav tsum tau tswj xyuas kom tau txais cov khoom xav tau ib txwm.
YPolyester
Polyesters yog cov polymers nrog ester ua haujlwm pab pawg. Txij li thaum muaj ntau esters, nws yog hu ua polyester. Muaj cov polyesters ntuj thiab hluavtaws polyesters. Muaj ntau ntau hom polyesters, nyob ntawm seb muaj pes tsawg leeg ntawm cov saw tseem ceeb. Lawv yog aliphatic, semi aromatic thiab aromatic polyesters. Polylactic acid thiab polyglycolide acid yog cov piv txwv rau aliphatic polyesters. Polyethylene terephthalate thiab polybutylene terephthalate yog semi aromatic polyesters, whereas vectran yog aromatic polyester. Synthesis ntawm polyester yog ua los ntawm cov tshuaj tiv thaiv polycondensation. Lub diol nrog diacid reacts los tsim ib qho kev sib txuas ntawm ester thiab qhov polymerization txuas ntxiv mus txog rau qhov xav tau polyester yog synthesized. Polyesters tau dav tsim thiab muaj kev lag luam loj tom qab polyethylene thiab polypropylene. Polyesters yog cov thermoplastics, yog li cov cua sov tuaj yeem hloov lawv cov duab. Tsis tas li ntawd, lawv tuaj yeem ua thermoset, ib yam nkaus. Thaum raug kub siab, lawv yog combustible. Polyester yog siv los tsim cov ntaub. Cov ntaub no yog siv los ua cov khaub ncaws xws li ris, tsho thiab tsho. Tsis tas li ntawd lawv tau siv los ua cov khoom vaj tsev zoo li cov ntaub pua tsev, cov pam vov, thiab lwm yam. Polyester fibers kuj siv los ua lub raj mis, lim, insulating tapes, thiab lwm yam. Cov polyesters ntuj yog biodegradable, yog li lawv tuaj yeem siv dua. Lawv muaj cov cuab yeej zoo thiab tshuaj lom neeg, uas tso cai rau lawv siv rau ntau lub hom phiaj raws li tau hais los saum no. Lwm qhov zoo dua ntawm polyester yog lawv cov tshuaj toxicity tsawg.
YPolyamide
Polyamide yog cov polymer nrog cov pab pawg amide. Monomer yuav tsum muaj ib pawg amine thiab ib pawg carboxylic ntawm ob qho kawg los ua ib qho polyamide. Thaum cov amine pawg ntawm ib molecule reacts nrog cov carboxylic pawg ntawm lwm molecule, ib tug dej molecule raug tso tawm, thiab ib tug peptide daim ntawv cog lus yog tsim. Muaj tej yam ntuj tso thiab dag polyamides. Proteins yog ntuj thiab tseem ceeb heev polyamide polymer pom nyob rau hauv cov kab mob lom. Nylon yog ib qho hluavtaws polymer, thiab nws yog thawj cov khoom siv hluavtaws zoo. Tsis tas li ntawd, nws yog ib qho ntawm feem ntau siv polymers. Polyamides yog siv rau textiles, tsheb thiab sportswear.
Qhov txawv ntawm Polyester thiab Polyamide yog dab tsi?
• Hauv polyesters, ester functional pab pawg yog tam sim no whereas nyob rau hauv polyamides, amide functional pawg yog tam sim no.
• Cov monomer ntawm polyester yuav tsum muaj pawg carboxylic thiab ib pawg hydroxyl, whereas polyamide monomer yuav tsum muaj pawg carboxylic thiab ib pawg amine.
