Two types of novel functionalized N-[4-(4′-hydroxyphenyloxycarbonyl)phenyl]maleimide and N-(4-{[2-(3-thienyl)acetyl]oxyphenyl}oxycarbonylphenyl)maleimide (MIThi) were synthesized starting from 4-maleimido benzoic acid. Photoinduced radical homopolymerization of MIThi and its copolymerization with styrene were performed at room temperature to give linear polymers containing pendant thienyl moieties using ω,ω-dimethoxy-ω-phenylacetophenone as an initiator. Copolymers' compositions and the equilibrium constant (K) for electron donor–acceptor complex formation suggest an alternating nature of the copolymerization. The monomer reactivity ratios and Alfrey–Price Q,e values were also determined. The thermal behavior of the new synthesized monomers and polymers was investigated by differential scanning calorimetry and thermogravimetric analysis. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 995–1004, 2002

Synthesis and characterization of thiophene-substituted N-phenyl maleimide polymers by photoinduced radical polymerization

Elastic waves in layered periodic curved beams

Electrochemical oxidation of bis-terthienyl-B (B = ethane, disulfide, diacetylene, acetylene, ethylene) has been investigated. Monomers without and with 3,3′′-dialkylsubstitution are regularly coupled to polymers alternating sexithiophene and B moieties. The corresponding terthienyl homopolymers have also been produced for comparison. The polymers obtained are characterized by cyclic voltammetry, EQCM, UV−vis, and FTIR spectroscopy, in situ ESR and in situ conductivity. The conductivities of p-doped polymers with ethane or disulfide bridges fall in a narrow range (1−5 × 10−2 S cm−1) and are practically the same as those of α,ω-dimethylsexithiophene (1 × 10−2 S cm−1), suggesting that conduction proceeds without the help of the links via a direct redox hopping between sexithiophene blocks of adjacent polymer chains. In the cases of diacetylene and acetylene, conduction changes from redox to bipolaron-type but only in the case of ethylene the conductivity jumps to high values (1−5 S cm−1) corresponding to th...

Electrochemical, Magnetic, and Electrical Properties of α,ω-Capped Sexithiophene Films. Part 3. Conduction in Poly(bis-terthienyl-B)s (B = Ethane, Disulfide, Diacetylene, Acetylene, Ethylene)

\n In this work, the elastic wave propagation and dispersion characteristics of a curved tapered frame structure is investigated analytically. Separately, wave propagation through uniform curved and straight tapered beam were reported in the existing literature; however, no literature reports the influence of simultaneous bent and taper on the wave propagation. In particular, the band characteristics for the curved and tapered beam with two types of cross-sections, i.e., rectangular and circular, are presented. The paper elucidates that introducing a small periodic bent angle cross-section produces a complete, viz. axial and flexural band gap in the low-frequency region, and conicity enhances the width of the band. It is also evidenced that a curved tapered frame with a solid circular cross-section induces a wider band gap than the rectangular section. A complete first normalized bandwidth of 159% is achievable for the circular cross-section and 123% in the case of the rectangular section. The complete result is presented in a non-dimensional framework for wider applicability. An analysis of a finite tapered curved frame structure also demonstrates the attenuating characteristics obtained from the band structure of the infinite structure. The partial wave mode conversion, i.e., generation of coupled axial and flexural mode from a purely axial or flexural mode in an uncoupled medium is observed. This wave conversion is perceived in reflected and transmitted waves while this curved tapered frame is inserted between the two uniform cross-section straight frames.

Wave Propagation in Tapered Periodic Curved Meta-Frame Using Floquet Theory

1, 4-bis(1-naphthyl)-buta-1,3-diyne, C24H14, Mr , ' 302.38, monoclinic, P2 1/a, a '7.534(1), b ' 6.012(1), c ' 17.969(3)A, β' 101.1(1)˚, V ' 798.67 A, Dx ' 1.257g/cc, F(000) ' 316, λ.(Mok)α ' 0.71073 A T '300 K, final R and wR are 0.0389 and 0.0457 respectively using 1281 reflections taken in least squares calculations.

Crystal Structure of 1,4-Bis(1-Naphthyl)- Buta-1,3-Diyne

Solid state 1,4-addition polymerisation of crystalline disubstituted diacetylenes(DAs) is known to give crystalline polydiacetylenes(PDAs)1 which exhibit very interesting optical and electronic properte5 because of the extended conjugation of π-electrons along the backbone2,3. The high and fast third order nonlinear optical response (x 3) shown by PDAs projects them as alternate materials for potential applications in electro-optics and all optical communication4 system in place of conventional inorganic materials. Efforts are being made to enhance the polarizability and conjugation along the PDA backbone to get enhanced x 3 response as it is related to the π -conjugation of the system.

Abhijit Sarkar

Papers

Optical Properties of Polydiacetylenes with π -Conjugating Substituents in Solution and Solid State