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In the present study, structural analyses using synchrotron grazing incidence X-ray scattering, specular reflectivity and ellipsometry were performed on thin films of two novel polynorbornene derivatives, chiral poly(norbornene acid methyl ester) and racemic poly(norbornene acid n-butyl ester), which are potential low dielectric constant materials for advanced microelectronic and display applications. These analyses provided important information on the structure, electron density gradient across the film thickness, chain orientation, refractive index and thermal expansion characteristics of the polymers in substrate-supported thin films. The structural characteristics and properties of the thin films depended on the tacticity of the polymer chain and were further influenced by the film thickness and thermal annealing history.

Cinnamate group is well-known for the dimerization reaction by ultraviolet irradiation and their anisotropic dimerization are used for aligning liquid crystals. In this work, we found that cinnamate groups attached to the flexible polymer backbone could be reacted by thermal energy as well as UV irradiation. Cinnamate group of flexible polymers shows different molecular orientation of cycloadducts, comparing with conventional polymers, and it also participates in insolubilization reaction by additional thermal treatment. The thermal insolubilization reaction of flexible cinnamate polymer might be appropriate for the enhancement of molecular orientation.

A styrene monomer t BQSt, having a tert -butyloxycarbonyloxy ( t -BOC)-protected quinizarin dye precursor as a pendent, has been copolymerized with N -(tosyloxy)maleimide (TsOMI) to obtain a dual functional polymer P( t BQSt/TsOMI). The polymer P( t BQSt/TsOMI), as a single component photoimaging system without using an external photoacid generator (PAG), was applied for fluorescent photopatterning by dry process based on the chemical amplification (CA) process. The TsOMI units in the polymer chains were responsible for photochemical generation of p -toluenesulfonic acid by UV exposure and the acid generated in the solution cast polymer film induced the catalytic deprotection of acid labile t -BOC groups of the quinizarin dye precursors. Accordingly, the quinizarin moieties were regenerated in the polymer chains by the CA process, thereby recovering the original color and fluorescence of the quinizarin dye. Fluorescent patterns were readily delineated on the thin polymer films by imagewise UV exposure even without a wet development process.

Di- and triblock copolymers of poly(ethylene oxide) (PEO) and poly( dl -valine-co- dl -leucine) were synthesized by ring-opening polymerization of N-carboxyanhydride (NCA)s of dl -valine and dl -leucine initiated by amine-terminated PEOs. The resulting block copolymers were characterized by 1 H NMR , FT-IR, DSC, and wide-angle X-ray diffraction (WAXD). Differential scanning calorimeter revealed that the melting temperature of triblock copolymer was lower than that of diblock copolymer and the study of WAXD patterns of triblock copolymer indicated that PEO segments are stretched during the copolymerization as shown in the formation of complex. The self-assembly behaviors of these di- and triblock copolymers in the aqueous solution showed various forms.

A homopolymer having pendentt-Boc-protected quinizarin moieties has been prepared for patterned fluorescence images. The homopolymer P{t-BQN (2-norbornenylmethyl di-tert-butoxycarbonylquinizarin)}5 was prepared by palladium-catalyzed addition polymerization. Thet-Boc-protecting groups of the polymer were efficiently removed during chemical amplification process and revealed original properties of quinizarin, allowing patterned fluorescence images in the polymer film.

Glycolide (GL) and e-caprolactone (CL) were copolymerized in bulk at relatively high temperatures using stannous octoate as a catalyst. To investigate the relationship among microstructure, thermal properties, and crystallinity, three series of copolymers prepared at various reaction temperatures, times, and comonomer feed ratios were prepared and characterized by 1 H and 13 C NMR, DSC, and wide-angle X-ray diffraction (WAXD). The 600-MHz l H NMR spectra provided information about not only the copolymer compositions but also about the chain microstructure. The reactivity ratios (r G and r G ) were calculated from the monomer sequences and were 6.84 and 0.13, respectively. In terms of overall feed compositions, the sequence lengths of the glycolyl units calculated from the reactivity ratios exceeded those measured from the polymeric products. Mechanistic considerations based on reactivity ratios, monomer consumption data, and average sequence lengths are discussed. The unusual phase diagram of GL/CL copolymers implies that the copolymer melting temperature does not depend on its composition alone but rather on the nature of the sequence distribution. The DSC and WAXD measurements show a close relationship between polymer crystallinity and the nature of the polymer sequence.

Fully multi-alicylic polymers designed for use as 193 nm photoresist materials have been synthesized by vinyl addition polymerization of tetracarbocyclic norbornene derivatives, t-butyl tetracyclo[4.4.0.1.2,5 17,10]dodec-8-ene-3-carboxylate (t-BDN) and 3-acetoxytetracyclo-[4.4.0.1.2,5 17,10]dodec-8-ene (AcODN). The alicyclic polymer backbones of these polymers provide plasma etch resistance and mechanical properties. Two pendant groups were introduced to provide the desired lithographic functions: the t-butyl carboxylate group as a carboxylic acid functionality masked by a protecting group undergoes acid-catalyzed thermolysis; and the acetoxy polar group influences adhesion, wettability and dissolution properties of the polymers. The polymer showed an acceptable high transmittance at 193 nm and good adhesion property. The plasma etch rates of the copolymer poly(t-BDN-co-AcODN) (85:15) using CF4/CHF3 mixed gas were 1.01 times with respect to a novolac based resist. The 0.2 μm line-and-space patterns were obtained with a dose of 45 mJ cm−2 using a KrF excimer laser stepper.

The thermal behavior of isothermally crystallized syndiotactic polystyrene (SPS) and 70/30 SPS/poly(2,6-dimethyl-1,4-diphenylene oxide) (PPO) blend was investigated by differential scanning calorimetry. Pure SPS, which was crystallized at Tc=220 and 240°C had single melting endotherm and multiple endotherms, respectively, whereas the 70/30 SPS/PPO blends showed the opposite behavior with respect to Tc. Investigation by polarizing optical microscopy and small angle X-ray scattering revealed that the rejected impurity (PPO in blend and noncrystallizable chains with low molecular weight in pure SPS) during SPS crystallization resides between primary lamellae of SPS and thus the recrystallization strongly suppressed for the pure SPS crystallized at Tc=220°C and the 70/30 SPS/PPO blend crystallized at Tc=240°C. This may induce single melting endotherm. In the pure SPS crystallized at Tc=240°C and the 70/30 SPS/PPO blend crystallized at Tc=220°C, the rejected impurity resided between SPS crystalline fibrils, which consist of lamellae. This may allow recrystallization between the primary lamellae which would exhibit sharp multiple melting endotherms.

It is well known that brittle polymers can be considerably toughened by the incorporation of miscible amorphous polymers or a thermoplastic elastomer. The effect of rubber toughening was studied via reactive extrusion to investigate the fracture mechanism and morphology controls of syndiotactic polystyrene (SPS)/poly(2,6-dimethyl-1,4-diphenylene oxide) (PPO) blends. Successful rubber toughening was achieved in compatibilization using reactive extrusion. The reactive polystyrene (RPS) as a compatibilizer and styrene–ethylene/butylene–styrene block copolymer (SEBS) as an impact modifier were used in an extrusion experiment. The impact strength was highly dependent on the blending condition and the composition. The best result was obtained by 2-step mixing; the first mixing of PPO with RPS (1.0 phr oxazoline content) and functionalized SEBS (f-SEBS, 0.4 phr maleic anhydride content) then followed with SPS mixing. Increase in RPS level gave rubber particle size reduction due to the reactions at the interfaces among polymer phases, as demonstrated by the decreased tan δ value. The storage modulus (E′) of SPS/PPO blends was decreased with increasing PPO content.

α,ω-Hydroxy-terminated vinyl prepolymers were prepared by radical polymerization of methyl methacrylate, butyl acrylate, styrene and vinyl acetate in the presence of allyl alcohol. The butyl acrylate prepolymer of molecular weight 3100 and functionality 2.2 was prepared by the following condition; [BA]=3.85 mol/l, [ACPROL]=0.128 mol/l and [AA]=0.90 mol/l at 110°C. The polyurethane reactions of the resulting telechelic polymers with hexamethylene diisocyanate were carried out to obtain vinyl polymer-based polyurethanes.

Styrene monomer was mixed with quaternary ammonium montmorillonites(org-MMTs) and polymerized in the presence of radical initiator. The resulting materials showed an expansion of interlayer distance. These hybrid materials exhibited higher thermal stability compared with the virgin polystyrene(PS) or PS/pristine-MMT microcomposite. PS/Bz-MMT, containing benzyl-unit similar to styrene in org-MMT, exhibited higher decomposition temperature even for MMT loading as low as 0.3wt.% compared with other PS/org-MMT hybrids. It was found that the structural affinity between styrene monomer and the organic group of org-MMT plays an important role in the structure and the properties of hybrid materials.

A new type of processable electroluminescent polymer containing tertiary amine linkage was prepared by typical Wittig reaction between bis(4-formylphenyl) n-butylamine and diphosphonium salt. The resulting polymer was highly soluble in common organic solvents so that it could be spun-cast onto glass plate coated with ITO electrode to give highly transparent homogeneous thin film. The molecular weight of the polymer determined by gel permeation chromatography using polystyrene standards is Mn = 4,500, Mw = 11,600. The structure of the polymer was confirmed by IR, UV-visible, and 1H-and 13C-NMR spectroscopy. We observed successfully the electroluminescence peaked at around 530 nm from the device made of the synthesized polymer. The current-voltage (I-V) curves showed typical rectifying diode characteristic.

The photoinitiated elimination of methoxy groups of poly(p-phenylene-1-methoxyethylene) and the photochemical doping of the resulting poly(phenylenevinylene) (PPV) were investigated. Upon irradiation and then heat treatment at 150°C, poly(p-phenylene-1-methoxyethylene) containing triphenylsulfonium hexafluoroantimonate was converted to PPV. The resulting PPV was observed to be conductive and its conductivity was 10 -2 -10 -3 S/cm. By a lithographic procedure, we produced a conducting pattern doped photochemically in a nonconjugated poly(p-phenylene-1-methoxyethylene) matrix

Synthesis of butadiene-based sequence-controlled copolymers that are composed of commercial monomers such as styrene, butadiene, and ethylene was investigated. New substituted cyclododecadiene derivatives, 9-phenyl-1,5-cyclododecadiene was synthesized by reductive-phenylation method from 1,5-cyclododecadiene-9-one and was polymerized with tungsten-based catalyst systems to obtain a microstructure-controlled terpolymer. A sequence-controlled 2 : 1 : 1 terpolymer of butadiene, styrene and ethylene was successfully synthesized. The glass transition of the terpolymer occurred at -33.6°C. © 1995 John Wiley & Sons, Inc.

In the search for the potential method to extract the free cholesterol from certain biological systems, a nonionic polymeric amphiphile was prepared from cholesterol-based monomer and acrylamide. This copolymer dispersed well forming vesicles when sonicated and was found to be effective for the extraction of cholesterol in water as the experiment with [14C]cholesterol indicated. Extraction became more effective as temperature was raised.

In search for the new synthetic methods which may lead to the copolymers of controlled mer sequences, several new carbocyclic and heterocyclic monomer systems such as 1,1-disubstituted 2-vinylcyclopropanes, 1-(p-anisyl)-2-vinylcyclopropanes, substituted 3,4-dihydro-2H-pyrans, substituted 4-vinyl-2-oxetanones and α-vinyl cyclic sulfones were synthesized and their polymerization behaviors were investigated. And other promising monomer systems were also examined.

Ring-Opening Metathesis Polymerization of 4,6-Diphenylcyclooctene: 2:1 Alternating Copolymer of Styrene and Butadiene

Nanoemulsions have recently become increasingly important as potential vehicles for the controlled delivery of cosmetics and for the optimized dispersion of active ingredients in particular skin layers. The preparation of conventional nanoemulsions requires mainly high-pressure homogenization, which is unproductive and requires high energy due to its lower efficiency, limiting their practical applications. In order to solve these problems novel nanoemulsions were studied using a model system of pseudo-ternary water/emulsifier/paraffin oil. Nanoemulsions were prepared by stirring a mixture of the tocopherol-containing block co-polymer emulsifier PPG-20 Tocophereth-50, paraffin oil, and distilled water at the Θ-point using weight fractions of the dispersed phase (φ) of 0.31 to 0.82 and an emulsifier content of 1.0 to 9 wt.%. The emulsifying property of PPG-20 Tocophereth-50 in nanoemulsions was compared with that of the conventional emulsifiers Tocophereth-43, a mixture of polysorbate 60 and sesquioleate (3/1), and phospholipids. Also the emulsifying property of PPG-20 Tocophereth-50 in the more hydrophilic oils caprylic/capric triglyceride and octyldodecanol was compared with that in paraffin oil. The stability and morphology of the resulting nanoemulsions were studied by visual inspection, optical microscopy, particle size analysis, and cryo-scanning electron microscopy. In the nanoemulsion systems containing caprylic/capric triglyceride and octyldodecanol, respectively, as an oil phase PPG-20 Tocophereth-50 showed emulsification properties similar to those in paraffin oil. The conventional emulsifiers Tocophereth-43, a mixture of polysorbate 60 and sesquioleate (3/1), and phospholipids did not give nanoemulsions with high-speed stirring. The block co-polymer nonionic emulsifier PPG-20 Tocophereth-50 was found to produce stable nanoemulsions of mean droplet diameters ranging from 204 to 499 nm. The emulsification method of high-speed stirring at the Θ-point using PPG-20 Tocophereth-50 was found to be very effective for the preparation of stable nanoemulsions useful for applications in skincare cosmetics, cosmeceuticals, and drugs.

New discogens based on the octasubstituted phthalocyanines (Pc) were synthesized: 2,3,9,10,16,17,23,24-octakis[dodecylthio-1-methyl]-phthalocyanine (1a), 2,3,9,10,16,17,23,24-octakis[4-(dodecylthio)-2-oxa-butyl]-phthalocyanine (1b), 2,3,9,10,16,17,23,24-octakis[dodecyloxy]-phthalocyanine (1c), phthalocyanine 2,3,9,10,16,17,23,24-octa-n-dodecanoate (1d), S-(+)-2,3,9,10,16,17,23,24-octakis[4-(dodecyloxy)-2-oxa-pentyl]-phthalocyanine (1e), as well as their corresponding copper complexes (CuPc) 2a, 2b, 2c and 2e. They were characterized by microanalysis, IR, 1H and 13C NMR spectroscopies, and their mesomorphic behaviors were examined with DSC and optical microscopic methods. The products exhibited the following optical textures and transition temperature ranges: focal conic (1a, 95-267°; 2a, 108-304°), linear default (1b, 52-247°; 2b, 70-255°; 1c, 75-269°; 2c, 78-310°), fan-shaped (1d, 58-303°; 2e, 29-191°). Chiral discogenic PcH2 1e, however, showed a cholestericlike texture (23-151°C) in which the ...

Poly(methyl methacrylate)–polystyrene composite particle latexes were prepared by poly(methyl methacrylate)-seeded emulsion polymerization of styrene employing batch, swelling-batch, and semibatch methods. The changes in particle morphology taking place during the polymerization reaction were followed by electron microscopy. Anchoring effect exerted by ionic terminal groups introduced by ionic initiator was found to be the main factor in controlling the particle morphology. The polymer particles obtained by oil-soluble hydrophobic initiators such as azobisisobutyronitrile and 4,4′-azobis-(4-cyanovaleric acid) gave the inverted core-shell morphology. Water-soluble hydrophilic initiator, K2S2O8, also gave the inverted core-shell morphology. However, in this case the occurrence of the halfmoonlike, the sandwichlike, and the core-shell morphologies were also observed depending upon the polymerization conditions. The distribution of terminal SO groups on the surface area of polystyrene particles could be controlled by initiator concentration and polymerization temperature. Viscosity of polymerization loci dictated the movement of polymer molecules, thus causing the unevenness of particle shape and phase separation at high viscosity state. Viscosity was controlled by the styrene/poly(methyl methacrylate) ratio, the addition of a chain transfer agent or a solvent which is common to polystyrene and poly(methyl methacrylate).