Cov roj hmab roj hmab butyl yog cov roj hmab dawb-zoo li cov roj hmab zoo li cov khoom siv ceev ntawm 0.92G \ / CM3. Nws yog tsis muaj ntxhiab, insoluble hauv dej, thiab soluble hauv hexane thiab chloroform. Cov khoom tseem muaj huab cua qis permeability, kev ua kom zoo nkauj, thiab ua tau zoo. Ozone kuj, tshuaj lom neeg kuj, hluav taws xob rwb thaiv tsev, cov kev tiv thaiv hluav taws xob, hluav taws xob nqus thiab lwm yam ntxwv.