Formation of homopolymers of ribonucleotides by polynucleotide phosphorylase is well known (1, 2). In this reaction, a polymerization of ribonucleoside diphosphates occurs with the elimination of inorganic orthophosphate. Reactions involving formation of polyadenylic acid from adenosine triphosphate with elimination of an inorganic pyrophosphate group have been described with enzymes from sever...

The free-radical homopolymerization of 1,3-bis(N,N,N-trimethylammonium)-2propylmethacrylate dichloride (di-M) and 1,3-bis(N,N,N-trimethylammonium)-2-propylacrylate dichloride (di-A) in aqueous solution yields cationic polyelectrolytes (PEL) with theoretical/structural charge spacing of only «0.12 nm. The high charge density causes condensation of «82% of the chloride counterions. The high level...

Morpholine-2,5-dione derivatives having substituents with benzyl-protected carboxylic acid, benzyloxycarbonyl-protected amine and p-methoxy-protected thiol groups, respectively, were prepared in 2958% yield by cyclization of the corresponding N-[(2RS)-bromopropionyl]L-amino acids. Polyesteramides with protected pendant functional groups were obtained by ringopening copolymerization of either &-...

Using a hydrolysis condensation of triethoxysilane to prepare a synthetic benzoxazine-bridged bis(triethoxysilane) compound (BS), a series of benzoxazine-bridged polysilsesquioxanes precursors were prepared with different degrees of hydrolysis condensation. Ring-opening thermal homopolymerization of the benzoxazine rings in these precursors was employed to obtain several organic–inorganic hybri...

High-level ab initio molecular orbital theory calculations have been used to calculate the rate coefficients and Arrhenius parameters for dimer models of the propagation steps for the free-radical homopolymerization of methyl acrylate and vinyl acetate at 298.15 K. Gas-phase Arrhenius parameters, as calculated under the hindered rotormodel, showed large deviations from the corresponding solutio...

Drug releasing shape memory polymers (SMPs) were prepared from poly(thiourethane) networks that were coated with drug loaded nanogels through a UV initiated, surface mediated crosslinking reaction. Multifunctional thiol and isocyanate monomers were crosslinked through a step-growth mechanism to produce polymers with a homogeneous network structure that exhibited a sharp glass transition with 97...

We report the preparation of a new class of copolymer films that consist of polymethylene (PM) with a low percentage ( approximately 1-4%) of randomly distributed ethyl ester side groups, consistent with poly(methylene-co-ethyl acetate). The films are prepared through a surface-catalyzed polymerization on gold surfaces upon exposure to a dilute solution of diazomethane (DM) and ethyl diazoaceta...

We report here the first application of the computationally efficient metadynamics approach for analyzing single-site olefin polymerization mechanisms. The mechanism of group 4 metallocenium catalysis for ethylene homopolymerization is investigated by modeling the ethylene insertion step at the cationic (η(5)-C5H5)Zr(CH3)2(+) center using molecular dynamics simulations within the Density Functi...

Polymer layered silicate (PLS) nanocomposites have been prepared with diglycidyl ether of bisphenol-A (DGEBA) epoxy resin as the matrix and organically modified montmorillonite (MMT) as the clay nanofiller. Resin-clay mixtures with different clay contents (zero, two, five and 10 wt%) were cured, both isothermally and non-isothermally, using a poly(ethyleneimine) hyperbranched polymer (HBP), the...

Two poly(3-hexylthiophene) (P3HT) macromers containing a donor polymer with a polymerizable methacrylate (MA) end group, P3HT-CH2-MA and P3HT-(CH2)2-MA, have been synthesized, and P3HT-(CH2)2-MA has been successfully homopolymerized and copolymerized with methyl methacrylate (MMA) into stereoregular brush polymers and graft copolymers, respectively, using chiral ansa-zirconocene catalysts. Macr...