Abstract Pulsed‐laser polymerization (PLP) in conjugation with molecular weight distribution (MWD) measurement has emerged as the method of choice for determining propagation rate coefficient k p free‐radical polymerizations. Detailed guidelines using this technique (including essential internal consistency checks) and reporting results therefrom are given by authors, members IUPAC Working Party on Modeling kinetics processes polymerization. The PLP‐MWD measurements from many laboratories...

Abstract Pulsed‐laser polymerization (PLP) in conjunction with molar mass distribution (MMD) measurement is the method of choice for determining propagation rate coefficient k p free‐radical polymerizations. The authors, members IUPAC Working Party on Modeling kinetics and processes , collate results from using PLP‐MMD to determine as a function temperature T bulk methyl methacrylate at low conversions ambient pressure. Despite coming several different laboratories, values are excellent...

Pulsed-laser polymerization (PLP) in conjunction with the analysis of molecular weight distribution (MWD) via size-exclusion chromatography (SEC) remains recommended by IUPAC Working Party on Modeling polymerisation kinetics and processes as method choice for determination propagation rate coefficients, kp, free-radical polymerization. kp data from PLP-SEC studies several laboratories ethyl methacrylate (EMA), butyl (BMA) dodecyl (DMA) bulk polymerizations at low conversion ambient pressure...

Abstract Investigations into the kinetics and mechanism of dithiobenzoate‐mediated Reversible Addition–Fragmentation Chain Transfer (RAFT) polymerizations, which exhibit nonideal kinetic behavior, such as induction periods rate retardation, are comprehensively reviewed. The appreciable uncertainty in coefficients associated with RAFT equilibrium is discussed methods for obtaining RAFT‐specific detailed. In addition, mechanistic studies presented, target elucidation fundamental cause...

Abstract Summary: Propagation rate coefficients, k p , for free‐radical polymerization of butyl acrylate (BA) previously reported by several groups are critically evaluated. All data were determined the combination pulsed‐laser (PLP) and subsequent polymer analysis size exclusion (SEC) chromatography. The PLP‐SEC technique has been recommended as method choice determination IUPAC Working Party on Modeling Polymerization Kinetics Processes . Application to acrylates proven be very difficult...

Abstract The problems of determining reliable, well‐characterized values kinetic parameters in free‐radical polymerizations are discussed. origins the fact that experimental determinations rate coefficients ostensibly identical systems often result quite different being reported can be ascribed to subtle mechanistic assumptions made data interpretation, which considered detail. A series recommendations assist overcoming these problems, and highlight their origins, presented, with emphasis...

A novel method to extract individual free-radical polymerization rate coefficients for butyl acrylate intramolecular chain transfer (backbiting), kbb, and monomer addition the resulting midchain radical, , is presented. The approach measuring kbb does not require knowledge of any other coefficient. Only dispersion parameter SEC broadening has be determined by fitting measured MWDs or should available from separate experiments. based upon analysis shift in position inflection point polymer...

Butyl acrylate (BA) solution polymerization (1.5 M in toluene) was investigated via single-pulse pulsed laser conjunction with electron paramagnetic resonance spectroscopy (SP-PLP-EPR) emphasis on the termination and transfer kinetics of system which two distinctly different types radicals, secondary chain-end radicals (SPRs) midchain (MCRs), are present. MCRs produced by intramolecular hydrogen (backbiting). They may react back to SPRs monomer addition. The evolution SPR MCR concentrations...

The mole percentage of dead chains (Tmol %) was quantified in a normal Cu-mediated atom transfer radical polymerization (ATRP) methyl acrylate with tris(2-pyridylmethyl)amine and tris[2-(dimethylamino)ethyl]amine as the ligands acetonitrile. value for Tmol % significantly exceeded values predicted conventional termination between two radicals. main reason additional loss chain-end functionality identified CuI-induced catalytic (CRT). mechanism proposed this CRT involves formation highly...

Benchmark propagation rate coefficient (<italic>k</italic>_p) data for the radical polymerization of methyl acrylate are provided.

Abstract This is the first publication of an IUPAC‐sponsored Task Group on “Critically evaluated termination rate coefficients for free‐radical polymerization.” The paper summarizes current situation with regard to reliability values k t . It begins by illustrating stark reality that there large and unacceptable scatter in literature , it pointed out some reasons this are relatively easily remedied. However, major reason inherent complexity phenomenon polymerization. our impression only...

Propagation rate coefficients (kp) for the homopolymerization of methyl acrylate (MA) and dodecyl (DA) were determined by pulsed laser polymerization (PLP)/size-exclusion chromatography (SEC) technique at pressures between 100 2000 bar. The activation volumes propagation step, ΔV#(kp), MA DA are identical within experimental accuracy, but clearly different from previously reported ΔV#(kp) methacrylate. For both alkyl acrylates methacrylates a pronounced family-type behaviour kp is seen, with...

The propagation rate coefficient, kp, for free-radical polymerization of nonionized methacrylic acid (MAA) in aqueous solution has been studied via pulsed laser (PLP) conjunction with aqueous-phase size-exclusion chromatography (SEC). PLP−SEC experiments were carried out between 20 and 80 °C within the entire concentration range from dilute containing 1 wt % MAA up to bulk polymerization. kp values which are determined under assumption that relevant monomer at radical site is identical known...

Pulsed laser polymerization (PLP) in conjunction with size-exclusion chromatography (SEC), both being carried out the aqueous phase, was used to determine propagation rate coefficients, kp, of nonionized acrylic acid (AA) at temperatures between 2 and 25 °C monomer concentrations, cAA, from 1 10 wt %. The product kpcAA,local is primary experimental quantity deduced via PLP−SEC technique. Assuming cAA,local be identical overall concentration, yields apparent kp values, which, upon enhancing...

The percentage of two types free radicals occurring within n-butyl acrylate pulsed laser polymerization (PLP) has been measured via ESR spectroscopy. Polymerization in solution toluene, at monomer concentrations between 0.50 and 2.53 mol L-1 temperatures −50 70 °C, was induced by 351 nm excimer pulses applied a repetition rate 20 Hz. spectra obtained low degrees conversion may be adequately represented superimposing six-component four-line spectrum assigned to secondary propagating (SPRs)...

Abstract The dependence of propagation and termination rate coefficients on conversion in free‐radical polymerization is described by a purely kinetic model which considers contributions segmental diffusion, translational reaction diffusion to also takes diffusion‐control the step into account. scheme provides satisfactory representation interpretation coefficient measured an extended range for ethylene, butyl acrylate, methyl methacrylate polymerization. Reaction primary importance at...

Abstract Propagation rate coefficients, k p , which have been previously reported by several groups for free‐radical bulk polymerizations of cyclohexyl methacrylate (CHMA), glycidyl (GMA), benzyl (BzMA), and isobornyl (iBoMA) are critically evaluated. All data were determined the combination pulsed‐laser polymerization (PLP) subsequent polymer analysis size‐exclusion chromatography (SEC). This so‐called PLP‐SEC technique has recommended as method choice determination IUPAC Working Party on...

Propagation rate coefficients, kp, of N-vinyl pyrrolidone (NVP) radical polymerization in aqueous solution have been measured via the pulsed-laser - size exclusion chromatography method (PLP−SEC) over an extended concentration range from 1.8 to 100 wt % NVP at temperatures between 2 and 60 °C. The SEC analyses carried out by a modified procedure using dimethyl acetamide as eluent. An about 20-fold increase kp is observed passing bulk reaction dilute solution. As with nonionized methacrylic...

Pulsed-laser polymerization (PLP) in conjunction with aqueous-phase size-exclusion-chromatography (SEC) was employed to determine the propagation rate coefficient, kp, of methacrylic acid (MAA) free-radical aqueous solution. This done over a wide range degree MAA ionization, at concentrations between 5 and 40 wt %, temperatures from 6 80 °C. Depending on monomer concentration, α, may largely affect kp. At % MAA, kp is lowered by about 1 order magnitude passing nonionized fully ionized...

Atom transfer radical polymerization (ATRP) equilibrium constants (KATRP) were measured during of methyl acrylate (MA) with CuIBr/CuIIBr2 in either dimethyl sulfoxide (DMSO) or acetonitrile (MeCN) the presence tris(2-pyridylmethyl)amine (TPMA) tris[2-(dimethylamino)ethyl]amine (Me6TREN) as ligand and ethyl 2-bromopropionate initiator. The ln(KATRP) values changed linearly volume fraction solvents reaction medium, allowing extrapolation for KATRP to bulk conditions, which 2 × 10-9 3 10-8 TPMA...