The metal-free polymerization of propylene oxide (PO) using a special class of alkene—N-heterocyclic olefins (NHOs)—as catalysts is described. Manipulation of the chemical structure of the NHO organocatalyst allows for the preparation of the poly(propylene oxide) in high yields with high turnover (TON>2000), which renders this the most active metal-free system for the polymerization of PO repor...

a copolymer of styrene and methyl styrene was synthesized by nitroxide - mediated “living” free radical polymerization )nmp). n-bromosuccinimide was used as a brominating agent to obtain a copolymer with bromine as its end group. this brominated copolymer was used as macro initiators for atom transfer  radical  polymerization  (atrp).  chemical  modifcation  of  the  clay  and transformation of...

poly(styrene-co-butyl acrylate)/clay nanocomposites were synthesized via in situ atom transfer radical polymerization using activators generated by electron transfer in the presence of a montmorillonite ion-exchanged with mixed surfactants of dodecyl trimethyl ammonium bromide and vinyl trimethyl ammonium chloride. the living nature of polymerization is confrmed by occurrence of narrow molecula...

Reversing controlled radical polymerization and regenerating the monomer has been a long-standing challenge for fundamental research practical applications. Herein, we report highly efficient depolymerization method various polymethacrylates synthesized by reversible addition-fragmentation chain-transfer (RAFT) polymerization. The process, which does not require any catalyst, exhibits near-quan...

Introduction Polysulfides play a critical role in the optimization of many chemical processes. Dimethyl disulfide (DMDS), for example, is used as coke inhibiting additive in steam cracking furnaces and can also be used as photolytic initiator during free radical polymerization.[1, 2] Also tetrasulfides are frequently used in chemistry, mostly as inhibitors during polymerization reactions. Despi...

We consider the APED model (activation-polymerization-epimerization-depolymerization) for describing the emergence of chiral solutions within a non-catalytic framework for chiral polymerization. The minimal APED model for dimerization can lead to the spontaneous appearance of chiral oscillations and we describe in detail the nature of these oscillations in the enantiomeric excess, which are the...

INTRODUCTION Polymer/clay nanocomposites, in which nanosized silicate plates of clay are uniformly dispersed in the polymer matrix, provide enhanced mechanical and thermal properties compared to conventional composites. Not all polymer and clay combinations will form nanocomposites: the compatibility and interfacial properties between polymer matrix and clay layers significantly influence the e...