A new monomer,vinyltriallylsilane（CB3）,having functionnal groups with different hydrosilylation reactivity was designed and synthesized by allylation reaction from vinyltrichlorosilane.Then,photocrosslinkable hyperb...A new monomer,vinyltriallylsilane（CB3）,having functionnal groups with different hydrosilylation reactivity was designed and synthesized by allylation reaction from vinyltrichlorosilane.Then,photocrosslinkable hyperbranched（poly（siloxysilane）） with terminal allyl groups was prepared via hydrosilylation reaction of vinyltriallylsilane（CB3） and dimethylbis（dimethylsiloxy）silane（A2） monomers at the presence of Karstedt catalyst,and characterized by means of FTIR,（）1H-NMR,（）29Si-NMR,and SEC/RI/MALLS technology.The polymerization process of A2 and CB3 monomers was studied in situ by using FTIR.It was found that silicon hydride would preferentially react with vinyl groups during the reaction. This can cause to the generation of an intermediate with one Si—H and three allyl groups.By using it to conduct further self-polymerization,hyperbranched polymer can be obtained.The degree of branching of the resulting hyperbranched poly（siloxysilane） was calculated to be 0.44 by quantitative（）29Si-NMR spectroscopy,and the weight average molecular weight was 12.1 kg/mol with its polydispersity of 2.52.Finally,the UV curing behavior of the resulting polymer initiated with different photoinitors was also investigated.展开更多
A carbosilane dendrimer based macrophotoinitiator（MPI-185） containing benzophenone moiety terminal groups was synthesized by a divergent hydrosilylation/allylation reaction sequence followed by alcoholysis of the si...A carbosilane dendrimer based macrophotoinitiator（MPI-185） containing benzophenone moiety terminal groups was synthesized by a divergent hydrosilylation/allylation reaction sequence followed by alcoholysis of the silicon chloride end groups.The structure of MPI-185 was characterized by FTIR,（）1H-NMR,（）13C-NMR,and（）29Si-NMR,and its intrinsic viscosity,molecular weight and polydispersity were meassured on by using a GPC complex system.Its reactivity was tested via curing a sensitive epoxy acrylate（EA） resin using FTIR,and the thermal property of films cured was measured by TGA.The results were compared with those of a small molecule photoinitiator（185）.It was found that the curring efficiency of macrophoinitiator（MPI-185） was satisfactory,and the thermal degradation temperature of EA resin cured with MPI-185 was also markedly improved.展开更多
In order to enhance the reactivity of the silyl-containing ceramic precursor,a hyperbranched silyl-containing polymer with low viscosity and plenty of terminal vinyl-groups was prepared.A novel AB4 type monomer,bis（N...In order to enhance the reactivity of the silyl-containing ceramic precursor,a hyperbranched silyl-containing polymer with low viscosity and plenty of terminal vinyl-groups was prepared.A novel AB4 type monomer,bis（N,N-diallylamino）methylsilane,was synthesized first by aminolysis of MeHSiCl2 and then was polymerized via hydrosilylation reaction using H2PtCl6 as the catalyst.The polymerization process was monitored by FT-IR spectroscopy.The polymer product was purified via precipitation using ethyl ether and acetonitrile and was analysed by using（）1H-NMR、（）29Si-NMR and FT-IR spectroscopy.The results indicated that the polymer was hyperbranched polycarbosilazane,and α-hydrosilylation was the main reaction.The degree of branching（DB） of the hyperbranched polymer was 0.56 calculated from the（）29Si-NMR spectrum,and the average molecular weight（Mw）was 13 580 g/mol determined by light scattering method.It was found that there still existed a lot of functional vinyl end groups,which can be used as promising reaction centers for curing or modification of the polycarbosilazane.展开更多
Two UV curable hyperbranchend polysiloxanes（Ⅰ and Ⅲ） containing vinyl and allyl end groups and an UV cationic curable hyperbranched polymer Ⅱ-Ep with epoxy end groups,were synthesized via the polyhydrosilylation ...Two UV curable hyperbranchend polysiloxanes（Ⅰ and Ⅲ） containing vinyl and allyl end groups and an UV cationic curable hyperbranched polymer Ⅱ-Ep with epoxy end groups,were synthesized via the polyhydrosilylation using AB2 type monomers.All hydrosilylation reactions were catalyzed by（Pt/C） or chloroplatinic acid.Three AB2 type monomers were synthesized via hydrolyzation of functional chlorosilane prepared by using Grignardeagents,and dichlorosilane.The molecular structures of the polymers were characterized by（）1H-,（）29Si-NMR,FTIR and GPC,and the UV-curing behaviors of polymers in different atmospheres and different photoaccelerators were also investigated.展开更多
Three hyperbranched poly（siloxysilanes） were prepared from AB3-type monomers at the presence of Karstedt catalyst.The detailed synthesis procedures of AB3-type monomers by reaction between γ-methacryloyloxy propylt...Three hyperbranched poly（siloxysilanes） were prepared from AB3-type monomers at the presence of Karstedt catalyst.The detailed synthesis procedures of AB3-type monomers by reaction between γ-methacryloyloxy propyltrimethoxysilane or vinyltrimethoxysilane with chlorosilane using anhydrous ferric chloride as the catalyst were described.This new approach can simplify the synthetic routes for hyperbranched polysiloxanes.FTIR,（）1H-NMR,(（）13C-NMR,)（）29Si-NMR,elemental analysis and SEC/MALLS were employed to identify the structure of the polymers. The analyses revealed that the reaction between alkoxysilane and chlorosilane could be feasibly catalyzed by anhydrous ferric chloride.The reaction of vinyltrimethoxysilane with chlorosilane could be carried out more easily than that of γ-methylacrylacyloxypropyltrimethoxylsilane with chlorosilane due to its steric hindrance effect.展开更多
文摘A new monomer,vinyltriallylsilane（CB3）,having functionnal groups with different hydrosilylation reactivity was designed and synthesized by allylation reaction from vinyltrichlorosilane.Then,photocrosslinkable hyperbranched（poly（siloxysilane）） with terminal allyl groups was prepared via hydrosilylation reaction of vinyltriallylsilane（CB3） and dimethylbis（dimethylsiloxy）silane（A2） monomers at the presence of Karstedt catalyst,and characterized by means of FTIR,（）1H-NMR,（）29Si-NMR,and SEC/RI/MALLS technology.The polymerization process of A2 and CB3 monomers was studied in situ by using FTIR.It was found that silicon hydride would preferentially react with vinyl groups during the reaction. This can cause to the generation of an intermediate with one Si—H and three allyl groups.By using it to conduct further self-polymerization,hyperbranched polymer can be obtained.The degree of branching of the resulting hyperbranched poly（siloxysilane） was calculated to be 0.44 by quantitative（）29Si-NMR spectroscopy,and the weight average molecular weight was 12.1 kg/mol with its polydispersity of 2.52.Finally,the UV curing behavior of the resulting polymer initiated with different photoinitors was also investigated.
文摘A carbosilane dendrimer based macrophotoinitiator（MPI-185） containing benzophenone moiety terminal groups was synthesized by a divergent hydrosilylation/allylation reaction sequence followed by alcoholysis of the silicon chloride end groups.The structure of MPI-185 was characterized by FTIR,（）1H-NMR,（）13C-NMR,and（）29Si-NMR,and its intrinsic viscosity,molecular weight and polydispersity were meassured on by using a GPC complex system.Its reactivity was tested via curing a sensitive epoxy acrylate（EA） resin using FTIR,and the thermal property of films cured was measured by TGA.The results were compared with those of a small molecule photoinitiator（185）.It was found that the curring efficiency of macrophoinitiator（MPI-185） was satisfactory,and the thermal degradation temperature of EA resin cured with MPI-185 was also markedly improved.
文摘In order to enhance the reactivity of the silyl-containing ceramic precursor,a hyperbranched silyl-containing polymer with low viscosity and plenty of terminal vinyl-groups was prepared.A novel AB4 type monomer,bis（N,N-diallylamino）methylsilane,was synthesized first by aminolysis of MeHSiCl2 and then was polymerized via hydrosilylation reaction using H2PtCl6 as the catalyst.The polymerization process was monitored by FT-IR spectroscopy.The polymer product was purified via precipitation using ethyl ether and acetonitrile and was analysed by using（）1H-NMR、（）29Si-NMR and FT-IR spectroscopy.The results indicated that the polymer was hyperbranched polycarbosilazane,and α-hydrosilylation was the main reaction.The degree of branching（DB） of the hyperbranched polymer was 0.56 calculated from the（）29Si-NMR spectrum,and the average molecular weight（Mw）was 13 580 g/mol determined by light scattering method.It was found that there still existed a lot of functional vinyl end groups,which can be used as promising reaction centers for curing or modification of the polycarbosilazane.
文摘Two UV curable hyperbranchend polysiloxanes（Ⅰ and Ⅲ） containing vinyl and allyl end groups and an UV cationic curable hyperbranched polymer Ⅱ-Ep with epoxy end groups,were synthesized via the polyhydrosilylation using AB2 type monomers.All hydrosilylation reactions were catalyzed by（Pt/C） or chloroplatinic acid.Three AB2 type monomers were synthesized via hydrolyzation of functional chlorosilane prepared by using Grignardeagents,and dichlorosilane.The molecular structures of the polymers were characterized by（）1H-,（）29Si-NMR,FTIR and GPC,and the UV-curing behaviors of polymers in different atmospheres and different photoaccelerators were also investigated.
文摘Three hyperbranched poly（siloxysilanes） were prepared from AB3-type monomers at the presence of Karstedt catalyst.The detailed synthesis procedures of AB3-type monomers by reaction between γ-methacryloyloxy propyltrimethoxysilane or vinyltrimethoxysilane with chlorosilane using anhydrous ferric chloride as the catalyst were described.This new approach can simplify the synthetic routes for hyperbranched polysiloxanes.FTIR,（）1H-NMR,(（）13C-NMR,)（）29Si-NMR,elemental analysis and SEC/MALLS were employed to identify the structure of the polymers. The analyses revealed that the reaction between alkoxysilane and chlorosilane could be feasibly catalyzed by anhydrous ferric chloride.The reaction of vinyltrimethoxysilane with chlorosilane could be carried out more easily than that of γ-methylacrylacyloxypropyltrimethoxylsilane with chlorosilane due to its steric hindrance effect.
