I. Lub luag haujlwm tseem ceeb ntawm dimethyl silicone roj hauv silicone sealants
Silicone sealant feem ntau yog tsim los ntawm polydimethylsiloxane (piv txwv li, dimethyl silicone roj) ua cov khoom siv hauv paus, ntxiv nrog cov nqi tsim nyog ntawm cov khoom siv, cov yas, cov tshuaj sib txuas, cov khoom sib txuas, thiab cov catalysts. Nyob rau hauv chav tsev kub, silicone sealant reacts nrog ya raws nyob rau hauv cov huab cua los tsim ib tug crosslinked network qauv, uas ces kho rau hauv ib tug elastic silicone roj hmab. Cov sealant no tau siv dav hauv ntau cov ntaub thaiv phab ntsa thiab cov phab ntsa pob zeb rau kev sib txuas thiab kev sib khi, nrog rau lub qhov rooj thiab qhov rais caulking thiab kho kom zoo nkauj sab hauv vim nws yooj yim ntawm daim ntawv thov, zoo heev UV tsis kam thiab siab / qis kub tom qab kho, thiab zoo adhesion rau feem ntau lub tsev substrates.
II. Cov nyhuv ntawm dimethyl silicone roj rau ntawm qhov chaw ziab lub sij hawm ntawm sealant
Lub sij hawm ziab saum npoo yog qhov tseem ceeb ntawm qhov kev ua tau zoo ntawm silicone lub tsev sealants, ncaj qha cuam tshuam rau lub sijhawm ua tiav. Raws li GB / T 14683-2017, "Silicon thiab Modified Silicone Building Sealants," lub sij hawm ziab ntawm silicone sealants nyob rau hauv cov txheej txheem yuav tsum tsis pub dhau 180 feeb.
Cov kev tshawb fawb qhia tau hais tias ua kom cov roj dimethyl silicone roj cov ntsiab lus ncua lub sij hawm ziab ntawm qhov chaw. Qhov no yog vim hais tias cov roj dimethyl silicone tsis muaj cov pab pawg reactive, tsis koom nrog hauv kev kho thiab kev sib txuas ntawm cov tshuaj tiv thaiv silicone sealant system, thiab nthuav tawm qee qhov kev muaj peev xwm tsiv teb tsaws, tsiv mus rau qhov sib cuam tshuam. Qhov no ua rau muaj qhov qis dua ntawm cov neeg ua haujlwm crosslinking ntawm qhov chaw sealant, yog li ua kom qeeb ntawm kev sib txuas thiab kev kho ceev.
Thaum cov roj dimethyl silicone roj cov ntsiab lus tsawg, nws cov nyhuv ntawm tus neeg sawv cev crosslinking concentration ntawm lub sealant nto tsis tseem ceeb; Txawm li cas los xij, ntawm cov ntsiab lus siab dua, tus neeg sawv cev crosslinking concentration ntawm sealant nto txo qis, uas ua rau lub sijhawm ua kom qhuav ntawm qhov chaw kom ntev. Kev tshuaj xyuas ntxiv tau qhia tias lub sij hawm ziab saum npoo ntawm dealcohol-raws li silicone sealants tau yooj yim cuam tshuam los ntawm dimethyl silicone roj cov ntsiab lus. Yog tsis muaj dimethyl silicone roj, lub sij hawm ziab saum npoo ntawm dealcohol-raws li sealant yog kwv yees li ob npaug ntawm oxime-raws li sealant; Thaum cov roj dimethyl silicone cov ntsiab lus nce mus rau 50% ntawm lub cev, lub sij hawm ziab saum npoo ntawm dealcohol-raws li sealant yog kwv yees li peb npaug ntawm oxime-raws li sealant. Qhov no yuav yog vim qhov sib txawv ntawm kev ua haujlwm ntawm cov neeg ua haujlwm crosslinking siv nyob rau hauv ob lub sealants. Qhov siab dua qhov kev ua haujlwm ntawm hydrolytic ntawm tus neeg sawv cev crosslinking, lub sijhawm luv ntawm qhov ziab ntawm qhov chaw thiab qhov nrawm dua qhov detackification ntawm sealant. Kev ua haujlwm hydrolytic ntawm tus neeg sawv cev crosslinking hauv dealcohol-raws li sealant yog qis dua li hauv oxime-raws li sealant, yog li nws lub sij hawm ziab saum npoo yog ntev dua, thiab lub sij hawm ziab saum npoo yuav qeeb qeeb nrog nce dimethyl silicone roj cov ntsiab lus.
III. Qhov cuam tshuam ntawm Dimethyl Silicone Roj ntawm Sagging ntawm Sealants
Sagging yog ib qho tseem ceeb qhia txog cov khoom rheological ntawm sealants, characterizing lub anti{0}}sagging kev ua tau zoo ntawm sealant sib koom. Qhov qis dua, qhov tsawg dua qhov sib txuas sealant yuav deform thiab ntws tom qab thov, uas yog qhov tseem ceeb tshwj xeeb rau cov pob qij txha ntsug lossis cov kab rov tav kab rov tav.
Cov kev tshawb fawb qhia tau hais tias ntxiv qhov tsim nyog ntawm dimethyl silicone roj rau lub sealant system tsis cuam tshuam rau nws sag; Txawm li cas los xij, thaum cov roj dimethyl silicone cov ntsiab lus nce mus rau ntau dua 30%, lub sealant sag nce ntxiv, tshwj xeeb tshaj yog nyob rau hauv cov pob qij txha kuaj. Tsis tas li ntawd, piv rau de-alcoholized thiab deoxime-raws li sealants, dimethyl silicone roj tsis muaj qhov sib txawv loj hauv nws cov nyhuv ntawm sag.
