Highly active metallocenes and other single site catalysts have opened up the possibility of polymerizing cycloolefins such as norbornene (N) or of copolymerizing them with ethene (E) or propene (P). The polymers obtained show exciting structures and properties. E-N copolymers are industrially produced materials, with variable and high glass transitions depending on the wide range of their micr...

exfoliated poly (chloromethyl styrene-co-styrene)-g-polyacrylonitryle/organo- modified montmorillonite [p(cmst-co-st)-g-pan/o-mmt] nanocomposite was synthesized through solution intercalation method by using atom transfer and nitroxide mediated radical polymerization. at first, poly (chloromethyl styrene-costyrene) copolymer was synthesized by nitroxide - mediated “living” free radical polyme...

The aim of this study was to evaluate the influence of techniques of composite resin polymerization and insertion on microleakage and microhardness. One hundred and eighty class II cavities were prepared in bovine teeth and assigned to six groups: G1 - bulk filling + conventional polymerization; G2 - bucco-lingual increments + conventional polymerization; G3 - bulk filling + soft-start polymeri...

Polymerization reactions are commonly effected by exposing monomer formulations to some initiation stimulus such as elevated temperature, light, or a chemical reactant. Increasingly, these polymerization reactions are mediated by enzymes--catalytic proteins--owing to their reaction efficiency under mild conditions as well as their environmental friendliness. The utilization of enzymes, particul...

Polybutadiene nanoparticles were synthesized via batch emulsion polymerization of butadiene in the presence of potassium persulfate, disproportionate rosinate potassium cation and t-dodecyl mercaptane as initiator, emulsifier and chain transfer agent, respectively. Polymerization reaction was performed at different temperatures (60, 70 and 80 °C). Conversion was measured at the various time int...

This tutorial review first details the uncontrolled microemulsion polymerization mechanism, and the RAFT polymerization mechanism to provide the necessary background for examining the RAFT microemulsion polymerization mechanism. The effect of the chain transfer agent per micelle ratio and the chain transfer agent aqueous solubility on the RAFT microemulsion polymerization kinetics, polymer mole...

Various types of controlled/living radical polymerizations, or using the IUPAC recommended term, reversible-deactivation radical polymerization (RDRP), conducted inside nano-sized reaction loci are considered in a unified manner, based on the polymerization rate expression, Rp = kp[M]K[Interm]/[Trap]. Unique miniemulsion polymerization kinetics of RDRP are elucidated on the basis of the followi...

Controlled hybridization of olefin-containing polymers prepared by two different polymerization methods, step-growth polymerization and chain-growth polymerization, was accomplished by macromolecular olefin cross-metathesis.

background and aims. despite the increasing demand for adhesive restorations in pediatric dentistry, polymerization shrinkage and subsequent marginal microleakage remains a problem. the aim of this study was to evaluate of the sealing ability of novel low-shrinkage composite silorane in class v cavity of primary canines in comparison with three types of composite resin. materials and methods. n...

This paper reviews preparation and applications of amylose supramolecules by means of phosphorylase-catalyzed enzymatic polymerization. When the enzymatic polymerization of α-D-glucose 1-phosphate (G-1-P) as a monomer was carried out in the presence of poly(tetrahydrofuran) (PTHF) of a hydrophobic polyether as a guest polymer, the supramolecule, i.e., an amylose-PTHF inclusion complex, was form...