Qhov Tseem Ceeb Qhov txawv - Ntuj vs hluavtaws roj hmab
Roj hmab tuaj yeem ua tau ob txoj hauv kev; ib txwm los yog artificially. Ob qho tib si ntuj thiab hluavtaws roj hmab tuaj yeem ua vulcanized, feem ntau nrog leej faj; tab sis nyob rau qee lub sijhawm tshwj xeeb, lwm tus neeg sawv cev kuj tau siv nyob ntawm cov khoom xav tau. Qhov sib txawv tseem ceeb ntawm cov roj hmab ntuj thiab cov roj hmab hluavtaws yog lawv cov keeb kwm. Ob leeg yog polymers, tab sis ntuj roj hmab yog tsim los ntawm cov latex tau los ntawm ib tsob ntoo, whereas hluavtaws roj hmab yog ib tug dag polymer tsim los ntawm kev siv roj av byproducts. Lawv muaj cov khoom sib txawv ntawm lub cev thiab tshuaj lom neeg thiab lawv cov ntawv thov kev lag luam sib txawv nyob ntawm cov khoom ntawd. Cov roj hmab ntau ntau yog siv los tsim cov tsheb log tsheb.
Natural Rubber yog dab tsi?
tsob ntoo roj hmab ntuj, Hevea brasilensis yog tsob ntoo ib txwm nyob rau Brazil; Nws kuj loj hlob hauv South East Asia, Africa, thiab South America. Cov roj hmab ntuj yog cov polymer uas yog tsim los ntawm cov kua txiv hmab txiv ntoo uas tau sau los ntawm tsob ntoo roj hmab no. Tom qab sau cov kua, nws raug rau huab cua nyob rau hauv lub tshav kub me ntsis.
Lub monomer ntawm cov roj hmab ntuj yog 2-methyl-1, 3-butadiene (isoprene), CH2=C(CH3)-CH=CH2. Cov tshuaj tiv thaiv polymerization yog:
nCH2=C(CH3)-CH=CH2 -[CH2-C(CH3)=CH-CH2n –
Natural roj hmab tau los ua kev lag luam muaj txiaj ntsig tom qab kev tsim cov roj hmab vulcanized (cua sov nyob rau hauv muaj leej faj) los ntawm Charles Goodyear. Nws muab cov roj hmab zoo heev, ruaj khov thiab sib xyaw ua ke.
Dab tsi yog Synthetic Rubber?
Synthetic roj hmab yog cov khoom tsim tawm polymer uas yog tsim los ntawm cov khoom siv roj av. Cov roj hmab hluavtaws kuj muaj ntau daim ntawv thov kev lag luam zoo ib yam li cov roj hmab ntuj; nyob rau hauv kev lag luam tsheb rau cov log tsheb, hoses, siv, flooring, qhov rooj, thiab qhov rais.
Piv rau cov roj hmab ntuj, cov txiaj ntsig tseem ceeb ntawm cov roj hmab hluavtaws suav nrog cov roj zoo thiab qhov kub thiab txias thiab muaj peev xwm los tsim cov khoom lag luam nrog qhov zoo tsis tu ncua. Cov hluavtaws hluavtaws ua los ntawm butadiene yog suav tias yog cov roj hmab hluavtaws tseem ceeb tshaj plaws.
Dab tsi yog qhov txawv ntawm Natural thiab Synthetic Rubber?
Composition & Production:
Natural Roj Hmab: Cov roj hmab ntuj yog lub ntuj polymeric compound tsim los ntawm cov roj hmab ntawm Hevea brasiliensis. Nws feem ntau muaj poly-cis-isoprene thiab qee cov kab tsis huv xws li cov proteins thiab av.
Synthetic Roj Hmab: Cov roj hmab hluavtaws yog cov khoom siv hluavtaws hluavtaws uas yog tsim los ntawm polymerization ntawm ntau yam roj av-raws li precursors uas hu ua monomers. Cov khoom siv roj hmab uas muaj ntau tshaj plaws yog styrene-butadiene, synthesized los ntawm copolymerization ntawm styrene thiab 1, 3-butadiene. Qee yam ntawm lwm cov hluavtaws hluavtaws polymers yog tsim los ntawm polymerization ntawm monomers xws li isoprene (2-methyl-1, 3-butadiene), chloroprene (2-chloro-1, 3-butadiene), thiab isobutylene (methylpropene) los ntawm kev ntxiv me me. kom muaj nuj nqis ntawm isoprene rau kev sib txuas. Cov polymers no tau sib xyaw nrog lwm cov monomers hauv qhov sib txawv los hloov lawv lub cev, tshuaj thiab cov khoom siv kho tshuab.
Properties:
Natural Rubber: Cov roj hmab ntuj yog cov khoom hnyav molecular polymeric thiab elastomer nrog viscoelastic zog. Nws yog insoluble nyob rau hauv ntau cov kuab tshuaj xws li dej, cawv, acetone, dilute acids thiab alkalis. Tab sis, nws yog soluble hauv ether, carbon disulfide, carbon tetrachloride, petrol, thiab turpentine. Raw ntuj roj hmab muaj zog tensile tsawg thiab puas resistant.
Synthetic Rubber: Muaj ntau hom roj hmab hluavtaws, thiab lawv cov khoom sib txawv ntawm ib hom mus rau lwm qhov. Qee qhov tseem ceeb tshaj plaws hluavtaws roj hmab nrog rau lawv cov khoom muaj npe hauv qab no.
| Qeb | Properties |
| Styrene butadiene roj hmab (SBR) | puas ua haujlwm, qis elasticity, zoo dua tshav kub thiab kev laus ua haujlwm, cov khoom siv hluav taws xob zoo heev |
| YPolybutadiene roj hmab (BR) | sib xyaw nrog SBR lossis NRrabrasion-tiv taus, zoo elasticity, hloov tau ntawm qhov kub thiab txias |
| Isoprene roj hmab (IR) | Ntau lub tshuab ntxhua khaub ncaws, pob tshab |
| Acrylonitrile butadiene roj hmab (NBR) | Roj thiab roj resistant, zoo kub distortion kub zog, puas resistant |
| Chloroprene roj hmab (CR) | Nplaim retardant, tiv taus roj, roj, huab cua thiab kev laus, abrasion resistant |
| Butyl roj hmab (IIR) | Tsawg permeability rau gases, resistant rau kev laus, ozone thiab tshuaj, zoo mechanical zog, puas resistant, zoo hluav taws xob rwb thaiv tsev zog |
