Kafukufuku ndi chitukuko cha dimethyldiethoxysilane

The general solution silicone resin imagwiritsidwa ntchito makamaka ngati polima woyambira wa zokutira zosagwira kutentha, zokutira zolimbana ndi nyengo komanso zida zamagetsi zotentha kwambiri.

1.2 kusinthika kwaukadaulo kwa utomoni wa silikoni

Mwa mitundu yonse ya ma polima silikoni, silikoni utomoni ndi mtundu wa silikoni mankhwala apanga ndi ntchito oyambirira. Poyerekeza ndi chitukuko chothamanga cha ukadaulo wokonzanso mphira wa silikoni, kuwongolera kwaukadaulo kwa utomoni wa silikoni sikuchedwa, ndipo zopambana zazikulu zaukadaulo ndizochepa. Pafupifupi zaka 20 zapitazo, chifukwa cha kupita patsogolo luso la onunkhira ma polima heterocyclic kutentha zosagwira, ena a iwo poyamba ntchito m'munda wa silikoni utomoni. Komabe, kawopsedwe ka zosungunulira ndi kuchiritsa koopsa kwa ma polima onunkhira a heterocyclic osamva kutentha kumachepetsa kugwiritsa ntchito kwawo. M'zaka zaposachedwapa, anthu anayamba kumvetsera kwambiri kafukufuku ndi chitukuko cha silikoni utomoni. Utomoni wa silicone uli ndi kutentha kwakukulu komanso kukana kukalamba. Kuchita bwino komanso kutsimikizira chinyezi kwa hydrophobic ndikwabwino komanso zabwino zina, pali zizindikiro kuti utomoni wa silicone ukhoza kukhala ndi malo okulirapo m'tsogolomu.

2. General silikoni utomoni

2.1 njira yopangira utomoni wambiri wa silikoni

Mitundu yosiyanasiyana ya ma silicones imakhala ndi zida zosiyanasiyana komanso njira zopangira. Mu pepala ili, njira yopangira mitundu ingapo ya utomoni wa silikoni imangoyambitsidwa.

2.1.1 methyl silikoni

2.2.1.1 kaphatikizidwe ka methylsilicone resin kuchokera ku methylchlorosilane

Methylsilicones amapangidwa ndi methylchlorosilane ngati zopangira zazikulu. Chifukwa cha kapangidwe kake ndi kapangidwe ka ma silicones (madigiri ophatikizika a silicone, mwachitsanzo, [CH3] / [Si] mtengo), mikhalidwe yosiyanasiyana yophatikizika ndiyofunikira.

Pamene otsika R / Si ([CH3] / [Si] ≈ 1.0) methyl silikoni utomoni ndi apanga, ndi hydrolysis ndi condensation anachita liwiro la zopangira monomers methyltrichlorosilane ndi mofulumira ndithu, ndi kutentha anachita ayenera mosamalitsa ankalamulira mkati 0 ℃ , ndi zimene ayenera kuchitidwa pawiri zosungunulira, ndi yosungirako nthawi anachita mankhwala firiji ndi masiku ochepa chabe. Zogulitsa zamtunduwu zilibe phindu lochepa.

Pakuphatikiza kwa R / Si methylsilicone resin, methyltrichlorosilane ndi dimethyldichlorosilane amagwiritsidwa ntchito. Ngakhale hydrolytic condensation reaction of the osakaniza methyltrichlorosilane ndi dimethyldichlorosilane ndi pang'onopang'ono kuposa methyltrichlorosilane yekha, hydrolytic condensation reaction liwiro la methyltrichlorosilane ndi dimethyldichlorosilane ndi osiyana kwambiri, amene nthawi zambiri amayamba ndi hydrolytic condensation wa methyltrichlorosilane in advance. The hydrolyzate si zogwirizana ndi chiŵerengero cha monomers awiri, ndi methyl chlorosilane nthawi zambiri hydrolyzed kupanga m'deralo crosslinking gel osakaniza, kuchititsa osauka mabuku katundu wa methyl silikoni utomoni analandira kuchokera hydrolysis wa atatu monoma.

2.2.1.2 kaphatikizidwe ka methylsilicone kuchokera ku methylalkoxysilane

Mlingo wa hydrolysis condensation wa methylalkoxysilane ukhoza kuwongoleredwa ndikusintha momwe zinthu ziliri. Kuyambira ku methylalkoxysilane, utomoni wa methylsilicone wokhala ndi magawo osiyanasiyana ophatikizika amatha kupangidwa.

Ma methylsilicones amalonda omwe ali ndi digiri yapakatikati ya crosslinking ([CH3] / [Si] ≈ 1.2-1.5) amakonzedwa kwambiri ndi hydrolysis ndi condensation ya methylalkoxysilane. The monomers wa methyltriethoxysilane ndi dimethyldiethoxysilane woyengedwa ndi deacidification ndi wothira madzi, anawonjezera ndi trace hydrochloric asidi kapena mlingo woyenera amphamvu asidi cation kuwombola utomoni (the catalysis zotsatira za macroporous amphamvu asidi ion kuwombola utomoni ndi bwino), ndi moyo. Dongo logonana (louma pambuyo pa acidification) limagwiritsidwa ntchito ngati chothandizira, kutentha ndi hydrolyzed. Pamapeto pake, onjezani kuchuluka kwa hexamethyldisilazane kuti muchepetse chothandizira cha hydrochloric acid, kapena sefa utomoni wosinthanitsa ndi ayoni kapena dongo lomwe limagwiritsidwa ntchito ngati chothandizira kuthetseratu kuyamwa kwa condensation. Chopangidwacho ndi yankho la mowa wa methylsilicone resin.

2.2.2 methyl phenyl silikoni

Zida zazikulu zopangira mafakitale a methylphenyl silicone resin ndi methyltrichlorosilane, dimethyldichlorosilane, Phenyltrichlorosilane ndi Diphenyldichlorosilane. Ena kapena onse omwe ali pamwambawa amawonjezedwa ndi zosungunulira toluene kapena xylene, osakanikirana bwino, amagwera m'madzi pansi pa chipwirikiti, kutentha komwe kumayendetsedwa ndi hydrolysis reaction, ndi HCl (hydrochloric acid aqueous solution), zomwe zimapangidwira, zimachotsedwa. mwa kutsuka madzi. The hydrolyzed silikoni njira anapezedwa, ndiyeno mbali ya zosungunulira ndi nthunzi kupanga moyikira silikoni mowa, ndiyeno silikoni utomoni wokonzedwa ndi kuzizira condensation kapena kutentha condensation anachita, ndi yomalizidwa silikoni utomoni amapezeka kudzera kusefera ndi ma CD.

2.2.3 cholinga chachikulu cha methyl phenyl vinilu silikoni utomoni ndi zigawo zake zogwirizana

Kapangidwe ka methyl phenyl vinilu silikoni utomoni ndi ofanana ndi methyl phenyl silikoni utomoni, kupatula kuti kuwonjezera methyl chlorosilane ndi phenyl chlorosilane monomers, kuchuluka kwa methyl vinilu dichlorosilane ndi vinilu ena okhala silikoni monomers anawonjezera mu hydrolysis yaiwisi yaiwisi. zipangizo. The monomers osakaniza anali hydrolyzed, osambitsidwa ndi anaikira kupeza anaikira hydrolyzed silanol, kuwonjezera zitsulo organic asidi mchere chothandizira, decompressing kutentha kwa predefined mamasukidwe akayendedwe, kapena kulamulira condensation anachita mapeto malinga ndi gelation nthawi, ndi kukonzekera methyl phenyl vinilu silikoni utomoni.

Methylphenyl hydropolysiloxane, yomwe imagwiritsidwa ntchito ngati gawo la crosslinker kuphatikiza momwe methylphenyl vinyl silikoni utomoni, nthawi zambiri imakhala mphete kapena liniya polima yokhala ndi digiri yaing'ono ya polymerization. Amapangidwa ndi hydrolysis ndi cyclization wa methylhydrodichlorosilane, kapena ndi CO hydrolysis ndi condensation wa methylhydrodichlorosilane, Phenyltrichlorosilane ndi trimethylchlorosilane.

2.2.4 silikoni yosinthidwa

Kupanga kusanganikirana kusinthidwa silikoni utomoni ndi organic utomoni nthawi zambiri mu toluene kapena xylene njira ya methylphenyl silikoni utomoni, kuwonjezera alkyd utomoni, phenolic utomoni, akiliriki utomoni ndi zina organic utomoni, mokwanira kusakaniza wogawana kupeza yomalizidwa mankhwala.

The copolymerized modified silicone resin imakonzedwa ndi machitidwe angapo a mankhwala. The organic utomoni kuti akhoza copolymerized ndi silikoni monga poliyesitala, epoxy, phenolic, melamine formaldehyde, polyacrylate, etc. A zosiyanasiyana njira kupanga angagwiritsidwe ntchito pokonzekera copolymerized silikoni utomoni, koma zothandiza kwambiri mafakitale kupanga njira ndi copolymerization wa silikoni mowa ndi. organic utomoni. Ndiko kuti, hydrolysis wa methyl chlorosilane ndi phenyl chlorosilane monomers palimodzi kupeza hydrolyzed pakachitsulo mowa njira kapena anaikira njira, ndiyeno kuwonjezera chisanadze apanga organic utomoni prepolymer ndi chothandizira, ndiye kusakaniza co kutentha evaporation zosungunulira, kuwonjezera nthaka, nthaka naphthenate ndi chothandizira ena, ndi condensation reaction pa kutentha kwa madigiri 150-170, mpaka zinthu anachita kufika mamasukidwe akayendedwe oyenera kapena anakonzeratu nthawi gelation, kuzirala, Kuwonjezera zosungunulira kupasuka ndi fyuluta kupeza yomalizidwa utomoni copolymerized silikoni.