Summary: The photopolymer recording material based on acrylamide monomer has been experimentally studied. After illumination with an interference field, the photopolymerization process is initiated and a diffraction grating is formed in real-time. The performance of the material depends on its chemical composition and recording parameters. Due to its self-developing characteristics, the real-time measurement of hologram formation is used for detection of the recording process. From the measurement, properties of the material can be determined and optimized for different holographic applications. 相似文献
Maleimides are gaining a great deal of attention in both scientific and industrial communities since they can be used in high performance macromolecular systems: thermosets with high temperature stability, self-healing systems, or in click chemistry reactions. After an introduction, this review reports in the first part the different routes to synthesize maleimides. In the second part, this review focuses on the use of maleimides in polymer synthesis, first through nucleophilic reactions, second via cycloaddition to yield remendable systems, and then via radical polymerization. Finally, the industrial availability of maleimides is discussed. 相似文献
Summary: Application of high pressure, up to 2 500 bar, in cumyl dithiobenzoate‐mediated styrene reversible addition fragmentation chain transfer (RAFT) polymerizations was found to be extremely advantageous with respect to both rate and control of polymerization. The overall rate of polymerization could be increased by a factor of approximately 3 with, e.g., at 23% conversion, concomitantly reducing the polydispersity indices from 1.35 to 1.10. No significant effect of increased pressure on the rate retardation effect was found.
SEC curves of polystyrene samples with identical peak molecular weights, generated by CDB‐mediated styrene bulk polymerization at 70 °C at 1 and at 2 000 bar. 相似文献
A hybrid cation-exchange monolith for high performance liquid chromatography (HPLC) was prepared by a one-pot synthesis with reverse-atom transfer radical polymerization, in which sodium bisulfite was used as the inorganic material, methyl methacrylate was used as organic material, 2, 2'-Azobisisobutyronitrile as initiator, and ferric trichloride as the inorganic catalyst. Moreover, sodium bisulfite was used to provide the sulfonic group. The conditions of polymerization were optimized. The chemical groups of the monolith were assayed by Fourier transform infrared spectroscopy; the morphology of monolithic material was investigated by scanning electron microscopy; the pore size distribution was determined by a mercury porosimeter; and the mechanical stability and permeability of the monolith were investigated by the back-pressure drop at several linear velocities. Finally, the monolith was used to separate human serum albumin from human plasma in conjunction with HPLC in 5 min, and the influences of buffer concentration and pH value on the elution of human serum albumin were investigated. In addition, the monolith was applied to separate lysozyme from egg whites in a short time (4 min) and separate a mixture of aromatic compounds. 相似文献
Summary : The activation-deactivation pseudo-equilibrium coefficient Qt and constant K0 (=Qt x PaT1,t = ([A1]x[Ox])/([T1]x[T])) as well as the factor of activation (PaT1,t) and rate constants of elementary steps reactions that govern the increase of Mn with conversion in controlled cationic ring-opening polymerization of oxetane (Ox) in 1,4-dioxane (1,4-D) and in tetrahydropyran (THP) (i.e. cyclic ethers which have no homopolymerizability (T)) were determined using terminal-model kinetics. We show analytically that the dynamic behavior of the two growing species (A1 and T1) competing for the same resources (Ox and T) follows a Lotka-Volterra model of predator-prey interactions. 相似文献