Photochemical reaction of Photopolymer pdf

Photochemical reaction of Photopolymer Students: Thu Tran Loi Nguyen Tuyen Duong Truong Duong Teacher: Hoan Vu Tran Outline  Introduction  Trung hop quang .(photopolymerization)  Photochemical reaction of photopolymer  Free radial  Cationic  Photocrosslinking  Photodegradation  Ung dung  Summary  Reference Introduction A photopolymer is a polymer that changes its properties when exposed to light, often in the ultraviolet frequency of the electromagnetic spectrum. Introduction Photochemical reaction of photopolymer Free Radial Free radial Photoinitiator Direct Photoinitiator In-direct Photoinitiator Norrish I Norrish II Electron transfer Hydrogen abstraction Direct Photoinitiator  Norrish I Direct Photoinitiator  Norrish II [...]... formed by chemical reactions that are initiated by radiation • Change physical properties of photopolymers Photocrosslinking Crosslinking by dichromate Photodegradation   Be degradation of a photodegradable molecule caused by the absorption of photons (light) Ex: photodegradation of diazonium salt N2Cl N2X O H X hv NH NH NH * * n=2-3 * n=2-3 * Photodegradation Ex:Photodegradation of aryl azid group... negligible adhesion Moderate/good good Reference    Polyme chuc nang va vat lieu lai cau truc nano book of Nguyen Duc Nghia Photoinititor for free radical and cationic polymerization by K.Dietliker The potential of cationic photopolymerization’ long lived active center of Beth Ann Ficek in Univerity of Iowa ... n=2-3 * Photodegradation Ex:Photodegradation of aryl azid group Ar hv N3 Ar Ex: Photodegradation of o-Naphthoquinone diazide O O O N2 hv O3S R N 2 O3S R H2O O3S R H2O COOH O3S R N Problem - hv O 2 O Problem hv Summary Comparision between free radical and cationic polymerization Property Radical Cationic Reaction rate high Moderate/high Initiator by light Light and heat Volume change large negligible . Vu Tran Outline  Introduction  Trung hop quang .(photopolymerization)  Photochemical reaction of photopolymer  Free radial  Cationic  Photocrosslinking  Photodegradation  Ung. Photochemical reaction of Photopolymer Students: Thu Tran Loi Nguyen Tuyen Duong Truong