Roj Hmab yog ib yam khoom uas muaj elastic heev uas muaj peev xwm ntawm reversible deformation. Nws muaj elasticity zoo nyob rau hauv chav tsev kub thiab muaj peev xwm undergo tseem ceeb deformation nyob rau hauv tsawg tsawg sab nraud quab yuam, thiab ces rov qab mus rau nws qub lub xeev thaum lub zog raug tshem tawm. Roj hmab yog ib qho amorphous polymer tag nrho nrog lub iav hloov pauv kub (Tg), thiab nws qhov hnyav molecular feem ntau loj heev, ntau tshaj li ntau pua txhiab.
Muaj ob hom roj hmab: roj hmab ntuj thiab hluavtaws roj hmab. Cov roj hmab ntuj yog ua los ntawm cov roj hmab uas tau muab rho tawm los ntawm cov nroj tsuag xws li cov ntoo roj hmab thiab cov nyom roj hmab; hluavtaws roj hmab yog tsim los ntawm polymerization tshwm sim ntawm ntau yam monomers. Cov khoom siv roj hmab tau siv dav hauv ntau yam ntawm kev lag luam thiab peb lub neej txhua hnub.
Hauv peb lub tebchaws kev lag luam, kev lag luam roj hmab yog ib qho tseem ceeb tshaj plaws hauv kev tsim kho kev lag luam. Nws muab cov khoom siv tseem ceeb txhua hnub - siv cov khoom thiab cov khoom siv roj hmab kho mob rau peb lub neej thiab nws tseem muab ntau yam khoom siv roj hmab rau kev lag luam hnyav xws li mining, tsheb thauj mus los, kev siv tshuab, hluav taws xob thiab lwm yam. Yog li peb tuaj yeem hais tias kev lag luam roj hmab tseem ceeb heev hauv ntiaj teb.
Xyoo 2004, tag nrho thaj chaw cog ntawm cov roj hmab ntuj hauv Suav teb yog nyob ib ncig ntawm 696200 hectares. Qhov chaw txiav yog 451900 hectares thiab cov roj hmab qhuav qhuav ntawm 573300 tons. Ntawm lawv, thaj chaw cog qoob loo cog qoob loo yog 411000 hectares, thiab thaj chaw ntiag tug yog 285200 hectares, suav txog 59.03% thiab 40.97% ntawm tag nrho cov roj hmab hauv lub tebchaws, raws li.
Txoj kev loj hlob ntawm Tuam Tshoj txoj kev lag luam roj hmab yog dav. Xyoo 2010, tag nrho cov khoom siv roj hmab hauv Suav teb tau nce mus txog 2.3 lab tons, thiab cov khoom lag luam ntawm kev lag luam roj hmab tau hloov pauv zoo. Peb lub teb chaws tau them nyiaj ntau rau kev txhim kho ntawm kev lag luam roj hmab. Ntau cov npoj yaig muaj qhov loj ntawm kev lag luam roj hmab thiab ntau tus neeg ua haujlwm hauv kev lag luam roj hmab. Ntawm no peb yuav qhia ntau hom roj hmab uas peb feem ntau pom hauv peb lub neej.
Ua ntej, Ntuj roj hmab.
Ntuj Roj Hmab yog cov roj hmab feem ntau siv hauv ntau qhov chaw. Nws yog ib qho khoom siv ntuj tsim los ntawm cis-1,4-polyisoprene. 91% mus rau 94% ntawm nws cov khoom yog roj hmab hydrocarbons (cis-1,4-polyisoprene). Qhov seem ntawm nws yog cov proteins, fatty acids, tshauv, thiab suab thaj uas tsis yog roj hmab.
Lub ntuj roj hmab peb feem ntau peb siv yog latex los ntawm Brazilian roj hmab ntoo. Nws yog elastic khoom tom qab solidification thiab ziab.
Qee cov neeg nyob hauv zos hauv Cetral thiab South America twb tau pib siv cov roj hmab ntuj ua ntej Columbus nrhiav tau lub tebchaws Asmeskas xyoo 1492.
Xyoo 1736, Fabkis thawj zaug tshaj tawm txog keeb kwm ntawm cov roj hmab, cov txheej txheem ntawm kev sau cov latex, thiab kev siv cov roj hmab ntuj hauv South America. Tom qab no Europeans pib nkag siab txog cov roj hmab ntuj thiab kawm ntxiv txog nws cov nqi siv.
Tom qab ntau tshaj 100 xyoo, tus kws tshawb fawb Asmeskas C. Goodyear tau tshawb pom qhov sib ntxiv ntawm sulfur thiab lead carbonate rau cov roj hmab hauv xyoo 1839. Nws pom tias tom qab qhov sib ntxiv, cov khoom siv roj hmab zaum kawg yuav tsis mos thiab nplaum txawm tias nws raug kub thiab tshav ntuj. Thiab nws tseem tuav zoo elasticity zoo li ua ntej. Lub sijhawm no, cov txheej txheem ntawm roj hmab vulcanization tau tsim. Thiab tom qab ntawd Natural roj hmab tau paub tiag tiag rau nws cov nqi tshwj xeeb thiab dhau los ua cov khoom siv tseem ceeb hauv ntau qhov kev lag luam.
Cov roj hmab ntuj muaj ntau yam zoo heev tshwj xeeb tshaj yog nws zoo heev resilience, rwb thaiv tsev, dej tsis kam, thiab plasticity, nrog rau cov khoom tseem ceeb xws li roj tsis kam, acid tsis kam, alkali tsis kam, kub tsis kam, txias tsis kam, siab tsis kam, thiab hnav tsis kam tom qab kev kho mob tsim nyog, yog li nws muaj ntau yam kev siv.
Piv txwv li, cov kaus mom los nag, hnab dej sov, thiab cov hlua khi hlua khi siv hauv peb lub neej txhua hnub; Cov chaw kho mob, hnab looj tes phais, cov hlab ntshav, thiab cov hnab looj tes; Ntau yam log tsheb siv hauv kev thauj mus los; Conveyor siv, thauj siv, kua qaub thiab alkali resistant hnab looj tes siv nyob rau hauv kev lag luam; Irrigation hoses thiab ammonia hnab siv hauv kev ua liaj ua teb; Lub suab balloons siv rau kev ntsuas huab cua; Sealing thiab shock resistant khoom siv nyob rau hauv kev sim; Lub dav hlau, tso tsheb hlau luam, phom loj, thiab lub npog ntsej muag roj siv los tiv thaiv lub tebchaws; Txawm hais tias siab -cov khoom siv txuj ci thiab thev naus laus zis xws li foob pob hluav taws, lub ntiaj teb dag lub ntiaj teb, thiab lub dav hlau tsis tuaj yeem ua yam tsis muaj roj hmab ntuj.
Los ntawm Hnub Qhia, peb pom tias txij li xyoo 2012, Tuam Tshoj cov khoom lag luam roj hmab kev lag luam tau ua tiav ib xyoos - ntawm - xyoo nce ntawm 6.47% hauv cov khoom tsim tawm, thiab ib xyoos - ntawm - xyoo nce ntawm 2.59% hauv kev tsim cov log tsheb. Ntawm lawv, kev tsim cov log tsheb radial tau nce los ntawm 3.13% xyoo-ntawm- xyoo, thiab kev tsim tag nrho cov hlau radial log tsheb tau nce 6.55% xyoo-rau- xyoo. Tus nqi hloov pauv radial mus txog 87.23%, nce ntawm 0.46 feem pua ntawm cov ntsiab lus xyoo-rau- xyoo.
