• Journal of Adhesion and Interface
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• v.12 no.2
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• pp.67-72
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• 2011

Acrylic pressure-sensitive adhesives are used in many different parts in the world. But acrylic acid in PSAs may occur unexpected results such as corroding adherends or producing by-products when applied within electronic devices. This study employed acrylic PSAs based on 2-ethylhexyl acrylate (2-EHA), 2-hydroxyethyl acrylate (2-HEA) and butyl acrylate (BA) with different coating thickness. There are two types of curing agents. One is methylaziridine derivative (MAZ) and the other is aluminum acetylacetonate (AlACA). This study examined the adhesion performance and curing behaviors using peel strength, probe tack and gel fraction. Also, the viscoelastic properties of acrylic PSAs were investigated from Advanced rheometric expansion system (ARES).

• Bulletin of the Korean Chemical Society
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• v.18 no.9
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• pp.1002-1006
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• 1997

1H NMR spectra of D2O solutions containing 2,2-dimethylaziridine (1) or 2-methylaziridine (2) and [SiW11COⅡO39]6- (SiW11Co) or [SiW11NiⅡO39]6- (SiW11Ni) exhibit separate signals for the free ligand and the complex, indicating that the ligand exchange is slow on the NMR time scale. Identified are two linkage isomers with the methyl group of 2 at trans or cis position with respect to the metal. The isotropic shifts of 1 and 2 coordinated to SiW11Ni originate mainly from the contact shifts, and they agree reasonably with the relative values reported for similar ligands coordinated to bis(2,4-pentanedionato)nickel(Ⅱ). The isotropic shifts for the SiW11Co complexes were separated into contact and pseudocontact contributions. The pseudocontact shifts show that (χ∥-χ⊥) is positive, while that for the SiW11Co complexes of pyridine derivatives is negative. This result indicates that the ordering of dxy and dxz, dyz orbitals in SiW11Co complexes can be reversed by ligands.

• YAKHAK HOEJI
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• v.40 no.5
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• pp.487-490
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• 1996

The 13-hydroxyberbine(1), derived from berberinephenolbetaine, has been derivatized to furnish a variety of compounds such as 13-oxoberbine(2), 13-thioberbine(3), 13-chloroberbi ne(4), 13-(2-methylaziridine)berbine(5) and 13-carbolactoneberbine(6). Antitumor activity of these compounds was tested.

• YAKHAK HOEJI
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• v.38 no.1
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• pp.91-96
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• 1994

Irradiation of the berberinephenolbetaine [1] effected valence tautamerization to five 8,14-cycloberbine[21, which was converted to the spirobenzylisoquinolines by regioselective C-N bond cleavage A variety of ring systems such as compounds [4], [5] and [6] were introduced by the structural modification of berberinephenolbetaine.

• YAKHAK HOEJI
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• v.38 no.4
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• pp.451-454
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• 1994

In accordance with reported references, 8-methyl-8,14-cycloberbine was derived from berberinephenolbetaine. On acidic treatment the 8-methyl-8,14-cycloberbines were converted easily to the compounds $1{\sim}7$ in good yields. We developed a novel method for a synthesis of the C8-N bond adduct compounds 8 and 9 from 8-methyl-8,14-cycloberbine by treatment with oxalyl chloride, and 1,3-dichloroaceton.