The autoxidation and the liquid phase oxidation of melts of low density polyethylene

Gol'dberg, V.M.; Paverman, N.G.; Akutin, M.S.; Kashina, G.N.

doi:10.1016/0032-3950(78)90354-4

Cited by 9 publications

(3 citation statements)

References 3 publications

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“…The first half of the decomposition curve was used to calculate the rate constant assuming the first-order kinetics. A least-squares fit of the data provided the rate constant of k d,POOH and k d,POOP , and the value of k d,POOH was in good agreement with that obtained by God'dberg et al 19 and the value of k d,POOP was slightly higher than that of diheptylperoxide 20 at each temperature. The concentration and half-time of the peroxides at each temperature are listed in Table II.…”

Section: Determination Of Peroxides Density and Decomposition Rate Cosupporting

confidence: 72%

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Kinetics study on melt grafting copolymerization of LLDPE with acid monomers using reactive extrusion method

Shi

Zhu

Cai

et al. 2006

J of Applied Polymer Sci

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Graft copolymerization in the molten state is of fundamental importance as a probe of chemical modification and reactive compatibilization. However, few grafting kinetics studies on reactive extrusion were carried out for the difficulties as expected. In this work, the macromolecular peroxide-induced grafting of acrylic acid and methyl methacrylate onto linear low density polyethylene by reactive extrusion was chosen as the model system for the kinetics study; the samples were taken out from the barrel at five ports along screw axis and analyzed by FTIR, 1 H NMR, and ESR. For the first time, the time-evolution of reaction rate, the reaction order, and the activation energy of graft copolymerization and homopolymerization in the twin screw extruder were directly obtained. On the basis of these results, the general reaction mechanism was tentatively proposed. It was demonstrated that an amount of chain propagation free radicals could keep alive for several minutes even the peroxides completely decomposed and the addition of monomer to polymeric radicals was the rate-controlled step for the graft copolymerization. The results presented here revealed that the relative importance of graft copolymerization compared with homopolymerization mainly depended on the monomer solubility and reactivity, while the process parameters such as reaction temperature also influenced the reaction tendency.

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Section: Determination Of Peroxides Density and Decomposition Rate Cosupporting

confidence: 72%

“…Graft chain transfer to P ⌺PM i ⅐ ϩ P 3 P⅐PM i (18) Homopolymer chain transfer to P ⌺HO Ϫ M i ⅐ ϩ P 3 P⅐ ϩ HOM i (19) Graft chain termination…”

Section: Reaction Mechanismmentioning

confidence: 99%

Kinetics study on melt grafting copolymerization of LLDPE with acid monomers using reactive extrusion method

Shi

Zhu

Cai

et al. 2006

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…Literature studies [50,52,57,60,61] have adopted kinetic parameters of the corresponding gas-phase reactions. The overall rate-limiting step revolves around formation and decomposition of hydroperoxides that follow an experimental reaction rate expression of k(T) = 1.5 × 10 10 exp(−73 (kJ/mol)/R·T) [L/(mol·s)] and k(T) = 2.5 × 10 14 exp(−146 (kJ/mol)/R·T) [s −1 ] respectively [21,62]. The latter accounts only for a typical unimolecular O-O bond fission (ROOH → RO˙+˙OH).…”

Section: Kinetic Considerationsmentioning

confidence: 99%