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UV-curable acrylic pressure-sensitive adhesives (acrylic PSAs) have many applications in industry. As the Si-wafers become thinner, the acrylic PSAs for MCP need to show proper adhesion and leave little residue on the Si-wafer after UV irradiation when released from the dicing tapes. Strong adhesion is required in the dicing process to hold the Si-wafer before UV irradiation. On the other hand, weak adhesion strength is required after UV irradiation to prevent damage to the Si-wafers during the pick-up process. This study employed semi-interpenetrating polymer network-structured dicing of acrylic PSAs in the Si-wafer manufacture process. The binder PSAs contained 2-ethylhexyl acrylate (2-EHA) and acrylic acid (AA). The adhesion performance of the peel strength on a Si-wafer was examined as a function of the UV dose. The results showed that the abovementioned two requirements were achieved using semi-IPN dicing acrylic PSAs using a hexafunctional acrylate monomer and a UV-curing system. FE-SEM and XPS reve...

Star-shaped, nonlinear optical (NLO) material was synthesized and its optical, thermal, and electro-optic properties were investigated. Three NLO-active dipolar chromophores containing a phenylene ring substituted with a bulky alkyl chain as a conjugation bridge were chemically bonded to the core of 1,1,1-tris(4-hydroxyphenyl)ethane to form a dendritic architecture. The chemical structure and purity of the chromophore were verified by NMR spectroscopy. The chromophore exhibited a broad absorption band centered at around 608 nm tailing up to 760 nm in toluene solution and also showed a discernible solvatochromic shift in more polar solvent. The chloroform solution of the dendrimer produced an absorption band with a red-shifted maximum as large as 28 nm when compared to that of the toluene solution. It was thermally stable up to 275 °C in a nitrogen atmosphere and had a glass transition temperature of 76 °C. In a preliminary result, the polymer film containing the dendritic compound exhibited a shift of 19 pm/V taken at 1.55 μ.

For the functional enhancement of chelating resins containing carboxylic acids, copolymer beads were prepared by suspension polymerization of styrene (St), methyl methacrylate (MMA), and divinylbenzene (DVB) in the presence of toluene as diluent. The phenyl rings of the beads were directly chloromethylated, and the carboxylic ester groups of the beads were converted into hydroxymethyl groups by reduction followed by chlorination to give chloromethyl groups, respectively. The chelating resins containing a pair of neighboring carboxylic acid groups (NCAGs) were obtained by the alkylation of chloromethyl groups in copolymer beads with diethyl malonate in the presence of sodium hydride followed by hydrolysis using aqueous alkali solution. Accordingly, the structural effects of the resins on the adsorption of heavy metal ions were investigated. Poly(St‐co‐DVB)‐based chelating resin containing NCAGs showed adsorption abilities toward heavy metal ions like Pb2+, Cd2+, and Cu2+, whereas poly(MMA‐co‐DVB)‐...

In the presence of a thiol catalyst, triphenylsilane mediates the reductive alkylation of electron-rich terminal alkenes R1R2CCH2 by organic halides R3Hal via electrophilic carbon-centred radicals R3˙. Reactions were carried out in benzene or dioxane solvent using di-tert-butyl hyponitrite (at 60 °C) or dilauroyl peroxide (at 80 °C) as initiators and good yields of the adducts R1R2CHCH2R3 were obtained with either methyl thioglycolate or triphenylsilanethiol as catalysts (5–10 mol% based on alkene). In the presence of the thiol, the slow direct abstraction of hydrogen from the silane by the nucleophilic adduct radical R1R2ĊCH2R3 is replaced by a cycle of more rapid polarity-matched reactions in which hydrogen-atom transfer to the adduct radical from the thiol is followed by abstraction of hydrogen from the silane by the derived thiyl radical, to regenerate the catalyst. In the absence of thiol, negligible yields of reductive alkylation products were obtained. The homochiral thiols, 1-thio-β-D-mannopyranose tetraacetate and 1-thio-β-D-glucopyranose tetraacetate, and the tetrapivalate and tetrabenzoate analogues of the latter were effective catalysts and reductive carboxyalkylation products with enantiomeric excesses up to 72% were obtained from prochiral alkenes. Homochiral samples of two of these adducts were obtained by recrystallisation and their absolute configurations were determined by X-ray diffraction.

Various 2-alkyl-2,3-dihydro-2-methylbenzofurans 4 can be easily synthesized from 2-aryloxypropionic acid ethyl esters 1 by 3 steps in good yields.

Both INOC and ISOC reactions of 1 which has two different double bonds in a molecule (allylic and homoallylic double bond) showed high regioselectivity for allylic double bond to make [5,5] ring system. INOC reactions of 1 and 6 showed high diastereoselectivity for 4-substituents, whereas ISOC reaction did for 6-substituents of tetrahydrofuroisoxazolines.

Both INOC and ISOC reactions of 1 which has two different double bonds in a molecule (allylic and homoallylic double bond) showed high regioselectivity for allylic double bond to make [5,5] ring system. INOC reactions of 1 and 6 showed high diastereoselectivity for 4-substituents, whereas ISOC reaction did for 6-substituents of tetrahydrofuroisoxazolines.

The reductive carboxyalkylation of electron-rich alkenes by α-halogenoesters in the presence of triphenylsilane under free-radical conditions is catalysed by thiols: prochiral alkenes give optically-active adducts when the thiol catalyst is homochiral.

In the presence of a thiol catalyst, triphenylsilane mediates the reductive alkylation of electron-rich terminal alkenes R1R2CCH2 by organic halides R3Hal via electrophilic carbon-centred radicals R3˙. Reactions were carried out in benzene or dioxane solvent using di-tert-butyl hyponitrite (at 60 °C) or dilauroyl peroxide (at 80 °C) as initiators and good yields of the adducts R1R2CHCH2R3 were obtained with either methyl thioglycolate or triphenylsilanethiol as catalysts (5–10 mol% based on alkene). In the presence of the thiol, the slow direct abstraction of hydrogen from the silane by the nucleophilic adduct radical R1R2ĊCH2R3 is replaced by a cycle of more rapid polarity-matched reactions in which hydrogen-atom transfer to the adduct radical from the thiol is followed by abstraction of hydrogen from the silane by the derived thiyl radical, to regenerate the catalyst. In the absence of thiol, negligible yields of reductive alkylation products were obtained. The homochiral thiols, 1-thio-β-D-mannopyranose tetraacetate and 1-thio-β-D-glucopyranose tetraacetate, and the tetrapivalate and tetrabenzoate analogues of the latter were effective catalysts and reductive carboxyalkylation products with enantiomeric excesses up to 72% were obtained from prochiral alkenes. Homochiral samples of two of these adducts were obtained by recrystallisation and their absolute configurations were determined by X-ray diffraction.

The reductive carboxyalkylation of electron-rich alkenes by α-halogenoesters in the presence of triphenylsilane under free-radical conditions is catalysed by thiols: prochiral alkenes give optically-active adducts when the thiol catalyst is homochiral.

In the presence of a thiol catalyst and a suitable initiator, a mixture of hexabutylditin and malonic acid brings about protodehalogenation of organic bromides and iodides by a radical-chain mechanism.