Taw qhia txog roj hmab
Lo lus roj hmab los ntawm Indian lo lus cau uchu, uas txhais tau tias "ntoo ntawm kua muag". Cov roj hmab ntuj yog tsim los ntawm coagulating thiab ziab cov latex uas ntws tawm ntawm tsob ntoo roj hmab thaum nws tapping. Xyoo 1770, British chemist J. Priestley tau tshawb pom tias roj hmab tuaj yeem siv los tshem cov cwj mem sau. Thaum lub sij hawm, cov khoom siv rau lub hom phiaj no hu ua roj hmab, thiab nws tseem siv niaj hnub no. Cov saw hlau molecular ntawm roj hmab tuaj yeem sib txuas. Cross-linked roj hmab muaj peev xwm rov qab tau sai thaum deformed los ntawm sab nraud quab yuam, thiab muaj lub cev zoo thiab txhua yam khoom thiab tshuaj lom neeg ruaj khov. Roj hmab yog cov khoom siv tseem ceeb ntawm kev lag luam roj hmab thiab siv dav hauv kev tsim cov khoom siv roj hmab xws li cov log tsheb, hoses, tapes, thiab cables. Clover ntoo muab cov roj hmab ua lag luam tshaj plaws. Thaum nws raug mob (xws li qia bark txiav),
Tsis tas li ntawd, fig ntoo thiab qee cov euphorbiaceae muab roj hmab. Lub teb chaws Yelemees tau sim kom tau cov roj hmab los ntawm cov chaw tsim khoom no thaum Ntiaj Teb Tsov Rog II thaum cov khoom siv roj hmab raug cuam tshuam, tab sis tom qab ntawd hloov mus ua cov roj hmab hluavtaws.
Cov ntoo roj hmab qub tau loj hlob nyob rau hauv South America, thiab tom qab hloov cov khoom siv dag zog, kuj tseem muaj cov ntoo roj hmab ntau nyob rau sab hnub tuaj Asia. Qhov tseeb, Asia tau dhau los ua qhov tseem ceeb tshaj plaws ntawm cov roj hmab.
Cov tawv nqaij ua los ntawm guayule tuaj yeem txo qhov rhiab heev.
raw khoom
Cov roj hmab ntuj yog tsim los ntawm latex, nyob rau hauv uas qee yam ntawm cov khoom siv tsis yog roj hmab tseem nyob hauv cov khoom siv roj hmab. Feem ntau hais lus, cov roj hmab ntuj muaj 92 feem pua mus rau 95 feem pua cov roj hmab hydrocarbons thiab 5 feem pua rau 8 feem pua tsis yog roj hmab hydrocarbons. Vim muaj ntau txoj kev ua, thaj chaw tsim khoom sib txawv, thiab txawm tias lub caij xaiv sib txawv, qhov feem ntawm cov khoom xyaw no yuav sib txawv, tab sis lawv nyob hauv qhov ntau.
Protein tuaj yeem txhawb cov roj hmab vulcanization thiab ncua kev laus. Ntawm qhov tod tes, cov protein muaj zog nqus dej, uas yuav ua rau cov roj hmab nqus dej noo thiab ua pwm, txo cov rwb thaiv tsev ua haujlwm. Protein kuj muaj qhov tsis zoo ntawm kev ua kom sov ntau lawm.
Cov acetone extract muaj qee cov roj fatty acids thiab sterols ntau dua, qee qhov ua raws li ntuj antioxidants thiab accelerators, thiab qee qhov uas pab cov dispersion ntawm hmoov complexing agents thiab softening ntawm raw roj hmab thaum lub sij hawm sib tov.
Cov hmoov tshauv feem ntau muaj cov ntsev xws li magnesium phosphate thiab calcium phosphate, thiab cov hlau me me xws li tooj liab, manganese thiab hlau. Txij li cov valence hlau ions sib txawv no yuav ua rau cov roj hmab aging, lawv cov ntsiab lus yuav tsum tau tswj.
Cov dej noo hauv cov kua nplaum qhuav yog tsawg dua 1 feem pua, thiab nws yuav evaporate thaum ua. Txawm li cas los xij, yog tias cov ntsiab lus noo noo siab dhau lawm, nws yuav tsis tsuas yog ua rau cov roj hmab nyoos yooj yim rau pwm thaum lub sijhawm khaws cia, tab sis kuj cuam tshuam rau kev ua cov roj hmab, xws li tus neeg sawv cev sib tov yog yooj yim rau agglomerate; cov txheej txheem calendering thiab extrusion yog ib qho yooj yim los tsim cov npuas; cov txheej txheem vulcanization ua rau huab cua npuas lossis spongy.