Browsing by Author "Lin, Chen-Lung"

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Micellar morphologies of self-associated diblock copolymers in acetone solution
(2007-05-21)
Tung, Pao-Hsiang
;
Kuo, Shiao-Wei
;
Chen, Shih-Chien
;
Lin, Chen-Lung
;
Chang, Feng-Chih
We describe the synthesis and solution morphologies of poly(vinyl phenol-b-styrene) (PVPh-b-PS) micelles and the effects that changing the copolymer composition and concentration have on self-assembly structures of PVPh-b-PS in acetone (a good solvent for PVPh). These PVPh-b-PS copolymers aggregated into spherical, rod-like, and vesicular morphologies. The transformations of the PVPh-b-PS block copolymer micelles in acetone depended on a number of parameters, including the relative block lengths, their concentrations, and the degree of self-association through hydrogen bonding of the coronal PVPh chains. We also investigated the morphologies of the micelles formed from acetone solutions of poly (4-tert-butoxystyrene-b-styrene) (PtBOS-b-PS) copolymers having the same degree of polymerization as the precursor of PVPh-b-PS copolymer before hydrolysis reaction. Our results indicate that the micelles formed from PVPh-b-PS copolymers in acetone were more complicated than those prepared from PtBOS-b-PS copolymers in acetone because hydrogen bonding occurs in the micelle corona of the PVPh block. Finally, we also discussed the morphology transition when the self-association hydrogen bonding of PVPh block was destroyed by adding proton acceptor poly(4-vinylpyridine) (P4vp). (c) 2007 Elsevier Ltd. All rights reserved.
Novel epoxy nanocomposite of low D-k introduced fluorine-containing POSS structure
(2007-02-15)
Wang, Yen-Zen
;
Chen, Wen-Yi
;
Yang, Chao-Chen
;
Lin, Chen-Lung
;
Chang, Feng-Chih
A nanoporous additives, polyhedral oilgomeric silisesquioxane containing eight functional hexafluorine groups, octakis(dimethylsiloxyhexafluoropropyl ether)silsesquioxane (OF) has been synthesized and blended with the UV-cured epoxy resin. The OF containing (10%) epoxy has significantly lower dielectric constant (2.65) than the plain epoxy (3.71). The incorporation of fluorine containing additives is well-known to reduce dielectric constant due to lower its polarizability. In addition, the presence of the bulky POSS structure is able to create additional free space or pores and further reduces the dielectric constant of the epoxy matrix. (c) 2007 Wiley Periodicals, Inc.
Novel nanocomposite of epoxy resin by introduced reactive and nanoporous material
(2007-12-01)
Yang, Chao-Chen
;
Chang, Feng-Chih
;
Wang, Yen-Zen
;
Chan, Chia-Ming
;
Lin, Chen-Lung
A reactive and nanoporous particle (OG) was introduced to UV-cured epoxy resin to form great low D-k material for electronic industrial. We expected the porous cage of OG to decrease the dielectric constant of UV-cured epoxy resin and multiple reactive functional groups (oxirane ring) of OG reacted with photoinitiator to increase the curing density of UV-cured epoxy resin. The glass transition temperatures (T-g) of epoxy increases with the increase of the OG content up to 10 phr due to the increase of crosslinking density. Excessive aggregation at highest OG content of 15 phr results in the reduced crosslinking density and T-g. The char yield of the composite increases with increase of OG content because stable Si and SiO2 are formed after thermal decomposition. The presence of OG results in the higher porosity and thus the lower dielectric constant.