• Bulletin of the Korean Chemical Society
• /
• v.8 no.2
• /
• pp.102-105
• /
• 1987

2-Methoxy-6-methyl-3,4-dihydro-2H-pyran ($1_a$), 2-ethoxy-3,6-dimethyl-3,4-dihydro-2H-pyran ($1_b$), and 2-ethoxy-3-methyl-6-ethyl-3,4-dihydro-2H-pyran ($1_c$) were prepared by (4 + 2) cycloaddition reaction from the corresponding vinyl ketones and alkyl vinyl ethers. Compounds $1_{a-c}$ were ring-open polymerized by cationic catalyst to obtain alternating head-to-head (H-H) copolymers. For comparison, copolymer of head-to-tail (H-T) was also prepared by free radical copolymerization of the mixture of the corresponding monomers. The H-H copolymer exhibited some differences in its $^1H$ NMR and IR spectra. However, significant differences were showed between the H-H and H-T copolymers in the $^{13}C$ NMR spectra. Also noteworthy was that$T_g$ value of H-H copolymer was higher than that of the corresponding H-T structure. Decomposition temperature of the H-H copolymer was lower than that of the H-T copolymer. All the H-H and H-T copolymers were soluble in common solvents.

• Polymer(Korea)
• /
• v.31 no.3
• /
• pp.255-262
• /
• 2007

In this work, two types of copolymers are manufactured by a radical polymerization to develop a material for humid membrane. Each copolymer contains three monomers that have functions to improve humid-resistance, membrane stability, flexibility, impedance, and adhesion to the electrode. MDBAB (N,N'-dimethyl-2-methacryloxyethyl-3-bromopropyl ammonium bromide) having a salt form decreases the impedance of the humid membrane and reacts with amines to produce a cross-linking structure. HEMA (2-hydroxyethyl methacrylate) has an important role which reduces the impedance and increases the adhesion strength to the electrode. The other monomers are DAEMA (N,N'-dimethylamino ethyl methacrylate), 4-VP(4-vinyl pyridine), and 2-EHA(2-ethylhexyl acrylate) and all the monomers are formulated with several compositions to make a humid membrane. At specific composition, we could attain a satisfactory results having good performance and long term durability.

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.358-358
• /
• 2006

The graft copolymerization of methyl methacrylate (MMA), butyl acrylate (BA) and acrylamide (AAm) onto oil palm empty fruit bunch (OPEFB) fiber were successfully carried out in aqueous solution using $H_{2}O_{2}/Fe^{2+}$ as initiator. For all monomers the percentage of grafting increases with the amount of monomer and can be controlled by setting the appropriate reaction conditions. The optimum reaction period were found to be 120 minutes for all monomers whereas the optimum temperature and the amount of initiator needed for grafting depend on the type of the monomer used. The mechanisms of grafting vinyl monomer onto OPEFB were proposed. The grafted products were characterized by gravimetric analysis, FTIR and SEM.

• Proceedings of the Korean Fiber Society Conference
• /
• 1996.10a
• /
• pp.53-58
• /
• 1996

The Chitin Thiocarbonate-Fe(II)-H2O2 redox initiator system was investigated for the graft copolymerization of acrylonitrile(AN) and acrylic acid(AA) monomers onto chitin powder. The reactions with vinyl monomers onto chitin were carried out under various the graft copolymerization conditions to elucidate the polymerization behavior in terms of graft yield. Reactions of chitin-acrylonitrile graft copolymer with hydroxyl amine hydrochloride and those with sodium hydroxide were conducted in order to obtain chitin-(amidoxime-co-acrylonitrile) and chitin-(acrylate-co-acrylamide) graft copolymers, respectively. The reaction efficiency was observed to depend on the alkali concentration, time, temperature, and the reactant concentrations. The prepared chitin derivatives were evaluated to find potential applications for use in wastewater treatments for adsorption and desorption of heavy metal ions as well as acidic and basic dyes.

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.10a
• /
• pp.63-64
• /
• 2003

As a part of a research on the development of polymeric textile finishing agents, polymerization of low molecular weight copolymers containing maleic anhydride residues have been studied. In order to obtain low molecular weight poly(maleic anhydride-co-vinyl acetate) copolymers, the feed ratio of the two monomers and the concentrations of initiator and chain transfer agent were varied in the copolymerization. The copolymers were characterized using GPC, NMR, FTIR, DSC, and TGA. Copolymers with molecular weights in the range 2,150 to 6,630 have been prepared and characterized. The hydrolysis of the anhydride groups of the copolymer in water is also discussed.

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.328-328
• /
• 2006

On mixing of 1,3-dehydroadamantane, 1, with electron-deficient vinyl monomers such as acrylonitrile and methyl acrylate in THF at r.t. in the absence of any initiator, the copolymerization spontaneously proceeded to give alternating copolymers in 28-88 % yield. By contrast, no reaction of 1 occurred, when isobutyl vinyl ether or styrene was mixed under the similar conditions. These contrastive results indicate the high electron density of a central s-bond in a strained [3.3.1]propellane derivative, 1. Alternating sequences of the resulting copolymers were characterized by NMR and MALDI-TOF-MS measurements. DSC and TGA measurements revealed the high thermal stability of the alternating copolymers containing bulky and stiff adamantane skeletons.

• Bulletin of the Korean Chemical Society
• /
• v.19 no.8
• /
• pp.851-856
• /
• 1998

2,4-Di-(2-vinyloxyethoxy)benzylidenemalononitrile (2a), methyl 2,4-di-(2-vinyloxyethoxy)benzylidenecyanoacetate (2b), 3,4-di-(2-vinyloxyethoxy)benzylidenemalononitrile (4a), and methyl 3,4-di-(2-vinyloxyethoxy)benzylidenecyanoacetate (4b), 2,5-di-(2-vinyloxyethoxy)benzylidenemalononitrile (6a), and methyl 2,5-di-(2-vinyloxyethoxy)benzylidenecyanoacetate (6b) were prepared by the condensation of 2,4-di-(2-vinyloxyethoxy)benzaldehyde (1), 3,4-di-(2-vinyloxyethoxy)benzaldehyde (3), and 2,5-di-(2-vinyloxyethoxy)benzaldehyde (5) with malononitrile or methyl cyanoacetate, respectively. Trifunctional divinyl ether monomers 2, 4 and 6 were polymerized readily by free radical initiators to give optically transparent swelling poly(vinyl ethers) 7-9. Polymers 7-9 were not soluble in common organic solvents such as acetone and DMSO due to crosslinking. Polymer 7-9 showed a thermal stability up to 300 ℃ in TGA thennograms.

• Bulletin of the Korean Chemical Society
• /
• v.21 no.6
• /
• pp.613-617
• /
• 2000

p-(2-Vinyloxyethoxy)benzylidenemalononitrile (4a), methyl p-(2-vinyloxyethoxy)benzylidenecyanoacetate (4b), 3,5-dimethoxy-4-(2'-vinyloxyethoxy)benzylidenemalononitrile (5a), methyl 3,5-dimethoxy-4-(2'-vinyloxy-ethoxy) benzylidenecyanoacetate (5 b), o-(2 -vinyloxyethoxy)benzylidenemalononitrile (6a), methyl o-(2-viny-Ioxyethoxy) benzylidenecyanoacetate (6b), 1,3-di-(2',2'-dicyanovinyl)-5-methyl-2-(2'-vinyloxyetioxy)benzene (7a), l,3-di-(2'-carbomethoxy-2'-cyanovinyl)-5-methyl-2-(2'-vinyloxyethoxy)benzene (7b), 2,3,4-tri-(2'-viny-Ioxyethoxy) benzylidenemalononitrile (8a), methyl 2,3,4-tri-(2'-vinyloxyethoxy)benzylidenecyanoacetate (8b), 2,4,6-tri-(2'-vinyloxyethoxy)benzylidenemalononitrile (9a), and methyl 2,4,6-tri-(2'-vinyloxyethoxy)benzyl-idenecyanoacetate(9b) were prepared by the condensation of the corresponding benzaldehyde 1-3 with malononitrile or methyl cyanoacetate, respectively. Vinyl ether monomers 4, 6, and 8 polymerized readily with radical initiators to yield crosslinked polymers 10, 12, and 14. However, compounds 5, 7, and 9 were inert to radical initiators due to the steric hindrance. The resulting polymers 10, 12, and 14 were not soluble in common solvents showing a thermal stability up to $300^{\circ}C$.

• Bulletin of the Korean Chemical Society
• /
• v.20 no.3
• /
• pp.307-313
• /
• 1999

2,4-Di-(2'-vinyloxyethoxy)benzylidenemalononitrile (la), methyl 2,4-di-(2'-vinyloxyethoxy)benzylidenecyanoacetate (lb), 3,4-di-(2'-vinyloxyethoxy)benzylidene malononitrile (2a), methyl 3,4-di-(2'-vinyloxyethoxy)benzylidenecyanoacetate (2b), 2,5-di-(2'-vinyloxyethoxy)benzylidenemalononitrile (3a), methyl 2,5-di-(2'-vinyloxyethoxy)benzylidenecyanoacetate (3b), 2,3-di-(2'-vinyloxyethoxy)benzylidenemalononitrile (4a), and methyl 2,3-di-(2'-vinyloxyethoxy)benzylidenecyanoacetate (4b) were prepared by the condensation of 2,4-di-(2'-vinyloxyethoxy)benzaldehyde, 3,4-di-(2'-vinyloxyethoxy)benzaldehyde, 2,5-di-(2'-vinyloxyethoxy) benzaldehyde, and 2,3-di-(2'-vinyloxyethoxy)benzaldehyde with malononitrile or methyl cyanoacetate, respectively. Trifunctional divinyl ether monomers 1-4 were polymerized readily with boron trifluoride etherate as a cationic initiator to give optically transparent swelling poly(vinyl ethers) 5-8 havina oxybenzylidenemalononitrile and oxycyanocinnamate, which is presumably effective chromophore for second-order nonlinear optical applications. Polymers 5-8 were not soluble in common organic solvents such as acetone and DMSO due to crosslinking. Polymers 5-8 showed a thermal stability up to 300 ℃ in TGA thermograms, which is acceptable for electrooptic device applications.

• Bulletin of the Korean Chemical Society
• /
• v.16 no.4
• /
• pp.336-340
• /
• 1995

3',5'-Dimethoxy-4'-(2-vinyloxyethoxy)-4-nitrostilbene 2 and 3',5'-dimethoxy-4'-(2-vinyloxyethoxy)-2,4-dinitrostilbene 5 were prepared by the reactions of 2-iodoethyl vinyl ether with 3',5'-dimethoxy-4'-hydroxy-4-dinitrostilbene 1 and 3',5'-dimethoxy-4'-hydroxy-2,4-dinitrostilbene 4, respectively. Monomers 2 and 5 were polymerized with cationic initiators to obtain polymers with 3',5'-dimethoxy-4'-oxy-4-nitrostilbene and 3',5'-dimethoxy-4'-oxy-2,4-nitrostilbene, which are presumably effective chromophores for second-order nonlinear optical application in the side chain. The resulting polymers 3 and 6 were soluble in DMSO and DMF. The inherent viscosities of the polymers were in the range of 0.28-0.33 dL/g in DMSO. Polymers 3 and 6 showed a thermal stability up to 250 ℃ in TGA thermogram, and the Tg values obtained from DSC thermograms were in the range of 81-87°.