Ib qho polymer zoo tib yam yog ib lub sijhawm ntev molecule uas muaj kev sib txuas ntawm cov khoom me me - monomers. Yog hais tias ib tug macromolecule yog tsim los ntawm ntau yam sib txawv ntawm ib tug molecules, ces qhov no yog ib tug copolymer uas combines ob los yog ntau tshaj sib txawv tebchaw.
Lawv tuaj yeem faib raws li cov qauv thiab cov txheej txheem ntawm kev sib txuas.
Regular copolymer
Hom yooj yim thiab nkag siab tshaj plaws. Hauv cov macromolecule nrog cov qauv tsis tu ncua, cov monomers hloov sib npaug: 1-2-1-2-1-2… Hais txog lawv cov khoom, cov copolymer tsis tu ncua yog qhov zoo tshaj rau cov tsis zoo: lawv muaj thermally ruaj khov thiab muaj lub cev zoo dua thiab mechanical zog (elasticity, lub zog, thiab lwm yam). Cov yam ntxwv ntawm lub copolymer, raws li txoj cai, muaj cov khoom ntawm cov khoom sib xws ntawm cov polymers sib xws thiab yog qhov chaw nyob nruab nrab ntawm lawv. Txoj kev tseem ceeb tshaj plaws ntawm kev tau txais yog copolycondensation: thaum ob qho tib si monomer molecules sib xyaw ua ke, ib qho dej molecule raug tso tawm.
Cov polymers tseem ceeb tshaj plaws hauv kev lag luam muaj qhov tseeb ntawm cov qauv stereoregular. Feem ntau cov no yog hluavtaws copolymer-rubbers,muaj cov butadiene thiab ib lossis ntau dua lwm cov monomers:
- Styrene-butadiene roj hmab yog polycondensation khoom ntawm butadiene thiab styrene (vinylbenzene).
- Nitrile butadiene roj hmab - muaj ntau yam ntawm ob qho tib si tsis tu ncua thiab tsis tu ncua (tom kawg, ntawm chav kawm, yog qhov zoo dua qub). Lub monomer yog tsim los ntawm butadiene thiab acrylonitrile molecules.
- Styrene-acrylic copolymer yog qhov tshwm sim ntawm cov polycondensation ntawm styrene thiab methacrylate, ib yam ntawm cov polymer.
Fibres yog qhov tshwj xeeb ntawm cov copolymer tsis tu ncua.
Fibres
Fibers - polymers tau los ntawm cov organic synthesis siv rau hauv kev lag luam textile. Yog li hu ua hluavtaws fabrics yog tsim los ntawm hluavtaws fibers. Lawv txawv ntawm ntuj tsim nyob rau hauv zoo mechanical qualities (tsis-creasing, lub zog, hnav tsis kam, tsis kam mus rau ntau yam deformations). Qee cov fibers hluavtaws yog copolymer:
- nylon yog cov khoom lag luam polycondensation ntawm hexamethylenediamine thiab adipic acid;
- lavsan yog monomer uas muaj condensed ethylene glycol thiab terephthalic acid.
Random copolymers
Lawv tau txais tib yam nrog qhov sib txawv uas nyob rau hauv cov qauv tsim, cov monomers tsis muaj qhov kev hloov pauv nruj, tab sis raug teeb tsa random. Hauv qhov no, lawv tsis sau cov ntawv dav dav ntawm monomer tshiab, tab sis qhiafeem pua ntawm cov molecules ntawm txhua hom. Feem ntau, ib qho random copolymer tuaj yeem muaj ob lossis peb lub ntsiab monomers thiab ob peb ntxiv, uas nws cov ntsiab lus nyob ntawm 1-5% - lawv tau siv rau kev ruaj khov thiab lwm yam kev hloov me me rau cov khoom ntawm cov polymer.
thawj cov roj hmab hluavtaws muaj cov qauv tsis sib xws. Tsuas yog monomer - butadiene - nyob rau hauv cov saw nyob rau hauv txawv configurations; muaj qhov sib txawv ntawm nws cov cis- thiab trans-isomers, thaum cov roj hmab ntuj muaj yuav luag tsuas yog cis-butadiene.
Tam sim no feem ntau cov roj hmab hluavtaws nrog cov khoom siv ntxiv yog random copolymer. Cov no yog fluororubbers, butyl roj hmab, muaj xws li copolymerized isobutylene thiab 1-5% isoprene, rubbers nrog ntxiv ntawm vinyl chloride, styrene, acrylonitrile thiab lwm yam polymer-forming compounds. Tseem muaj xws li cov polymer, hu ua roj hmab, tab sis tsis muaj butadiene los yog isoprene nyob rau hauv nws muaj pes tsawg leeg. Nws yog copolymer ntawm polypropylene thiab polyethylene, ethylene-propylene roj hmab. Nws muaj, raws li koj yuav twv, ntawm cov monomers ntawm ethylene thiab propylene, muaj li ntawm 40 mus rau 70% ntawm molar loj ntawm ethylene.
Block copolymers
hom copolymer no yog tus cwj pwm los ntawm qhov tseeb tias hauv cov qauv kawg cov monomers tsis sib xyaw nrog ib leeg, tab sis tsim cov blocks. Txhua qhov thaiv yog ib yam khoom hauv qhov ntau uas nws muaj kev cuam tshuam tag nrho cov khoom ntawm nws cov polymer zoo tib yam. Qee lub sij hawm ntawm cov blocks sib txawv yuav muaj ib qho molecule ntawm lwm qhov sib xyaw - tus neeg sawv cev sib txuas.
Block polymers yog cov hu ua thermoplastic elastomers. Qhov no yogLub tebchaw ntawm cov blocks ntawm thermoplastics - polystyrene, polyethylene los yog polypropylene - thiab elastomers - butadiene thiab isoprene polymers, lawv random copolymer nrog styrene, ethylene-propylene copolymer twb paub rau peb. Raws li ib txwm muaj, cov thermoplastic elastomers zoo ib yam li elastomers hauv lawv cov khoom siv kho tshuab, tab sis thaum kub kub lawv tig mus rau hauv cov yas loj thiab tuaj yeem ua tiav ib yam li cov thermoplastics.
Graft copolymers
Ntxiv rau cov pab pawg tseem ceeb, graft copolymers muaj cov ceg ntoo ntxiv - chains los ntawm lwm cov monomers, luv dua qhov ntev ntawm cov saw tseem ceeb. Cov ceg tuaj yeem txuas mus rau cov pab pawg nruab nrab molecules.
Txhawm rau kom tau txais cov khoom cog qoob loo, koj thawj zaug xav tau cov saw hlau ua tiav ntawm lub ntsiab polymer. Tsis tas li ntawd, cov saw hlau sab tuaj yeem "sewn" rau nws nyob rau hauv ob txoj kev sib txawv: los qhia ib lub monomer rau hauv cov tshuaj tiv thaiv, uas nyob rau hauv tej yam kev mob polymerizes thiab txuas nyob rau hauv daim ntawv ntawm ib tug saw rau lub ntsiab polymer, los yog "cog" npaj txhij- ua cov saw luv (oligomer) mus rau lub ntsiab polymer los ntawm ib pawg neeg nruab nrab.
Graft copolymers yog tsim los ua kom pom kev hloov pauv ntawm cov pob txha pob txha polymer. Xws li cov khoom siv ntxiv ntawm cov khoom ntawm graft copolymer yog siv: lawv lub cev thiab cov yam ntxwv ntawm cov khoom siv yog txiav txim siab ib txhij los ntawm cov polymers ntawm ob lub ntsiab thiab sab saw.
