Kugadzirwa kweReactive Diluents- (Free-Radical UV-Rapiable Diluents)

Nzira dzekugadzira acrylate reactive diluents dzinosanganisira direct esterification, transesterification, acid chloride method, phase-transfer catalysis, uye addition esterification. Zvisinei, ruzhinji rwacho runogadzirwa kuburikidza ne direct esterification.

(1) Kujekesa Kwakananga

CH₂=CHCOOH + ROH -chinobatsira→ CH₂=CHCOOR + H₂O

  Zvinhu zvinowanzoshandiswa pakugadzira esterification zvakananga zvinosanganisira sulfuric acid yakakangwa, p-toluenesulfonic acid, uye methanesulfonic acid. Kushandisa sulfuric acid yakakangwa sechinhu chinobatsira pakugadzira esterification kunowanzo kukonzera migumisiro yakadai sekushaya mvura mumuviri, oxidation, uye kuzvigadzirisa kwe reactants. Izvi zvinogadzira zvigadzirwa zvakasiyana-siyana, zvinoomesa kucheneswa kwechigadzirwa uye kudzoreredzwa kwezvinhu zvakabikwa, zvinokanganisa maitiro ekurapa mushure mekurapwa, uye zvinokanganisa kunaka kwechigadzirwa uku zvichikuvadza michina. Nekuda kweizvozvo, PTSA inonyanya kushandiswa mukugadzirwa kwemaindasitiri nekuda kwezvakanaka zvayo, zvinosanganisira zvinodiwa zvishoma zvedosi, tembiricha shoma yemhinduro, mwero wekuchinja, uye mhando yepamusoro yechigadzirwa. Kana reaction yapera, catalyst inogona kuparadzaniswa zviri nyore nechigadzirwa, zvichiita kuti process workflow ive nyore. Mvura inogadzirwa panguva ye esterification reaction inobviswa uchishandisa azeotropic entrainer (dehydrating agent). Zvinhu zvinowanzo shandiswa zvinosanganisira benzene, toluene, xylene, cyclohexane, uye n-heptane, izvo zvinoumba azeotropes nemvura inobatwa kuti iendeswe nayo. Alkanes dzinodhura uye dzinoshanduka-shanduka; xylene ine poindi yekufashaira yakanyanya; benzene ine poindi yekufashaira yakaderera uye inoshanduka-shanduka zvakanyanya, zvichiita kuti zviome kupora, uye ine chepfu yakawanda. Saka, toluene inowanzo shandiswa se entrainer. Toluene ine poindi yekufashaira ye110°C uye poindi yekufashaira yeazeotropic yeazeotropic ye84°C; inopfava nyore panguva yekubvisa vacuum distillation solvent stripping, zvichiita kuti pave nekupora kwakanyanya, chepfu yakaderera pane benzene, uye mutengo wayo wakaderera. Zvisinei, mumakore achangopfuura, mitemo yemitemo pa solvents dze benzene-series mu coatings, inks, uye adhesives yakaita kuti vagadziri vazhinji vabvise toluene vachisarudza alkane-based entrainers. Zvinodzivirira polymerization zvinofanira kuiswa panguva ye esterification process kudzivirira polymerization isati yasvika ye acrylic acid monomer uye acrylate product inobuda. Zvinodzivirira polymerization zvinowanzo shandiswa zvinosanganisira phenolic compounds (dzakadai se hydroquinone [HQ] uye tert-butylhydroquinone [TBHQ]), amine compounds (dzakadai se phenothiazine uye p-phenylenediamine), uye copper coordination complexes (dzakadai se copper dimethyldiethyldithiocarbamate uye copper dibutyl dithiocarbamate), zvinoshandiswa zvega kana se blended formulation. Kune alkyl acrylates yakakwira, melt esterification inogona kushandiswa. Nzira iyi inobvisa kudiwa kwe entrainer uye inoderedza chiyero chinodiwa che catalysts uye inhibitors. Mushure me reflux reaction pa 110–120°C, kushaya mvura mumuviri kunoitwa, uye acrylic acid isina kugadziriswa uye mvura yakasara inobviswa kuburikidza ne vacuum distillation, zvichiita kuti alkyl acrylates yakakwira ive yakachena uye ine goho rakakura.

(2) Kuchinja kwemasero eropa kuita maester

CH₂=CHCOOCH₃ + ROH → CH₂=CHCOOR + CH₃OH

  Pakugadzirira alkyl acrylates yakakwira kana ma acrylates anoshanda kuburikidza ne transesterification, methyl acrylate inowanzo sarudzwa sechinhu chekutanga chealkyl ester yakaderera. Nekuda kwekudzikira kwayo (80°C), esterification inofanira kuitwa patembiricha yakaderera, izvo zvinorebesa nguva ye reaction. Uyezve, methanol inogadzirwa nechibereko inogadzira azeotrope ine methyl acrylate (boiling point 62–63°C), iyo inotakura reactant methyl acrylate uye nekudaro inoderedza goho re ester yakakwira. Methyl acrylate nema acrylates akakwira anowanzo kuve ne copolymerization uye homopolymerization, zvichideredza goho re acrylates yakakwira; saka, kuwedzerwa kwemishonga inodzivirira kunowanzo dikanwa. Nekuda kwemitengo uye kuoma kwekurapa, nzira iyi haichashandiswi mukutengeserana mukugadzira alkyl acrylates yakakwira uye ma acrylates anoshanda.

(3) Nzira yeAcid Chloride

CH₂=CHCOOH + SOCl₂ → CH₂=CHCOCl + HCl + CO₂

CH₂=CHCOCl + ROH → CH₂=CHCOOR + HCl

  Nzira iyi inotanga yasangana neacrylic acid nethionyl chloride kuti igadzire acryloyl chloride, iyo yobva yasangana ne esterification reaction ne alcohol. Hazvidi catalysts kana entrains. Nekuti reaction inoitika patembiricha yakaderera, kuwedzerwa kwepolymerization inhibitors kunodziviswawo. Esterification inoitika nehuwandu hwakawanda, zvichipa kuchena kwakanyanya kwechigadzirwa. Zvisinei, inzira ine matanho maviri ine mitengo yakakwira yekugadzira. Reaction iyi inogadzira huwandu hwakawanda hweHCl neSO₂ gases, zvichida masisitimu ekukwesha ane matanho akawanda ane diluted alkaline solutions nemvura kuti inyudzwe.

(4) Kugadziriswa kweKutapurirana kwePaseji (PTC)

2CH₂=CH₃|C-COOH + Na₂CO₃ → 2CH₂=CH₃|C-COONA + CO₂ + H₂O

CH₂=CH₃|C-COONA + ClCH₂-CH₂O → CH₂=CH₃|C-COOCH₂-CH₂O + NaCl

  Sodium methacrylate iripo sechinhu chakasimba, nepo epichlorohydrin iri mvura. Kana pasina catalyst, kuita pakati pazvo kunononoka, zvichiita kuti pave nekushandiswa kwe phase-transfer catalyst (PTC). Catalysts dzakakodzera dze phase-transfer dzinosanganisira quaternary ammonium salts, quaternary phosphonium salts, uye crown ethers. Quaternary ammonium salts ndidzo dzinonyanya kuwanikwa, dzakadai secetyltrimethylammonium chloride (CTAC), benzyltrimethylammonium chloride (BTMAC), uye tetramethylammonium chloride (TMAC). Kuvapo kwehunyoro mu reaction system kunokonzera side reactions; saka, kuti zviwedzere goho, zvese zvinhu zvakagadziriswa uye reaction system zvinofanirwa kuchengetedzwa zvisina mvura uye zvakaoma.

(5) Kuwedzera Esterification

CH₂=R₁|C-COOH + CH₂-CH₂O-R₂ → CH₂=R₁|C-COO-CH₂-OH|CH₂-R₂

  Nekuisa ethylene oxide kana propylene oxide zvakananga mu (meth)acrylic acid kana paine catalyst, kuwedzera kwe ring-opening esterification kunoitika, kugadzira hydroxy (meth)acrylates (senge HEA, HEMA, HPA, kana HPMA).