Radiation-inotangwa maitiro inogona kurongeka semhando mbiri: (1) crosslinking uye scission uye (2) kubatanidza uye kurapa.
Crosslinking ndiyo intermolecular bond kugadzirwa kwepolymer cheni.The degree of crosslinking inoenderana neradiation dose.Izvo hazvidi unsaturated kana mamwe magroups anoshanda.Nezvimwe zvisizvo (semumapolymer ane aromatics), haina kusiyana zvakanyanya nemakemikari chimiro.Haisi kusiyana zvakanyanya nekushisa.Kunyangwe iyo nzira yekuyambuka-inobatanidza nemwaranzi yakaongororwa kubva payakatanga kuwanikwa, hapasati paine chibvumirano chakapararira pane iyo chaiyo.Iyo meshini yekuyambuka inowanzosiyana nemapolymer ane chekuita.Nzira inogamuchirwa nepasi rose inosanganisira kutsemuka kwechisungo cheC-H pane imwe polima cheni kuti igadzire atomu rehydrogen, kuchiteverwa nekubviswa kweatomu rehydrogen rechipiri kubva mucheni yakavakidzana kugadzira molecular hydrogen.Zvino maviri akatarisana epolymeric radicals anosanganiswa kuita crosslink. Mhedzisiro yese yekuchinjika ndeyekuti molecular mass yepolymer inowedzera zvishoma nezvishoma neradiation dose, zvichitungamira kumaketani anemapazi kusvika, pakupedzisira polymer network yetatu-dimensional kana polima imwe neimwe yabatanidzwa. kune imwe ketani.
Mukupesana, scission ndiyo inopesana maitiro ekuyambuka umo kuputika kweC-C bondsoccurs.Crosslinking inowedzera huremu hwema molecular asi iyo yekupedzisira inoideredza.Kana simba remwaranzi rakakwira, kutyora kweketani kunoitika kuburikidza nekutsemuka kweC-C bond.Mune aeratedsolution medium, zvisinei, iyo mechanistic nzira ye scission inoenderera nenzira isina kunanga.Thepolymeric free radicals inogadzirwa ne-solvent-free radicals, iyo yakatoumbwa nemwaranzi.Kuwedzerwa kweokisijeni ne polymeric free radicals inoumba peroxy species, iyo pakuora-nzvimbo inoumba mamorekuru maduku.Iyo oxidative degradation yemapolymers zvinoenderana neyakagadziriswa muhurongwa.Chaizvoizvo, iyo polymer degradation inokwikwidza neiyo oxidation yezvinonyungudutsa.
Grafting inzira iyo mamonomers anounzwa akatevedzana kune polymer cheni uko ascuring ndiko kukurumidza polymerisation yeoligomer monomer musanganiswa kuti igadzire jaketi, iro rinonyanya kusungirirwa nemasimba emuviri kune substrate.Nenzira yakapfava, nzira dzakadai dzinosanganisira masisitimu akasiyana-siyana, iyo substrate iri firimu, shinda kana kunyange poda, ine monoma semvura ineat, mhute kana mhinduro.Pane hukama hwepedyo pakati pekubatanidza nekurapa kunyangwe paine misiyano yakati.Chaizvoizvo, hapana muganhu wenguva yegadziriro yekubatanidza.Zvinogona kutora maminetsi, maawa kana mazuva, nepo kurapa kuchiwanzo kukurumidza kuitika kunoitika muchikamu chechipiri.Mukubatanidza, covalent C-C zvisungo zvinoumbwa nepo mukurapa, kubatana kunowanzo sanganisira weakervan der Waals kana London dispersion forces.van der Waals bonding inoshanda kure kure uko kune kushoma kana kusina kudhumhana kana kuchinjana uye inowanzobatanidzwa nemasimba madiki.Nekudaro, covalentbonding, inoshanda pazvinhambwe zvidiki zvepakati penyukireya uye inosanganiswa nekupindirana kweelectron, kuchinjana, uye nekudaro masimba akakwira.Chimwe chinhu chakakosha pakurapa maitiro ndeye mukana wekuti kubatanidzwa pamwe chete nekurapa kunoitika zvichitungamira kune kuvandudzwa kwezvinhu zvechigadzirwa chapera, kunyanya mukunamira uye kuchinjika.
Kubatanidza kunoitika nenzira nhatu dzakasiyana: (a) pre-irradiation;(b) peroxidation uye (c) mutual irradia-tion technique.Mune pre-irradiation tekinoroji, yekutanga polymer musana inovhenekerwa muvacuum kana pamberi pegasi inert kuumba mahara radicals.Iyo irradiated polymer substrate inozobatwa nemonomer, inova mvura kana mhute kana semhinduro mune yakakodzera solvent.Nekudaro, mune iyo peroxidation grafting nzira, hunde yepolymer inoiswa kune yakakwira-simba mwaranzi pamberi pemhepo kana oxygen.Mhedzisiro ndeyekuumbwa kwe hydroperoxides kana diperoxides zvichienderana nemhando yepolymeric musana uye neradiation mamiriro.Zvigadzirwa zveperoxy, izvo zvakatsiga, zvinobva zvarapwa nemonomer patembiricha yakakwira, kubva ipapo maperoxides anozoora toradicals, anobva atanga kubatanidza.Chakanakira nzira iyi ndechekuti yepakati peroxyproducts inogona kuchengetwa kwenguva yakareba isati yaita danho rekubatanidza.Nekune rimwe divi, neiyo mutual irradiation tekinoroji iyo polymer uye monomers inovhenekerwa panguva imwe chete kugadzira iwo emahara radicals uye nekudaro kuwedzera kunoitika.Sezvo mamonomeri asina kuratidzwa nemwaranzi mu pre-irradiation tekinoroji, mukana uri pachena weiyo nzira ndeyekuti haina kusununguka kubva mudambudziko rehomopolymer kugadzirwa kunoitika nehunyanzvi hwekuita panguva imwe chete.Nekudaro, iyo yakasarudzika kusarudzika kweiyo pre-irradiation tekinoroji ndiko kutsetseka kwebase polymer nekuda kwekutungamira kwayo, izvo zvinoburitsa zvakanyanya kuumbwa kwe block copolymers kwete graftcopolymers.
Nguva yekutumira: May-03-2017