Melt grafting of a basic monomer on to polyethylene in a twin-screw extruder: reaction kinetics

Oliphant, Ken; Russell, K. E.; Baker, W. E.

doi:10.1016/0032-3861(95)99004-e

Cited by 33 publications

(20 citation statements)

References 9 publications

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“…However, at present system, while the homopolymerization rate and MH decreased beyond the reaction temperature 190°C, the graft rate and GD continued to increase with the increasing temperature. The same tendency was also observed by other researchers, 12,40 which can be explained as follows: as the propagation rate constant for very small radicals is a function of a molecular size, the oligomerization may occur over ceiling temperature even when high polymer formation is forbidden. 11,41 In the experiment, the graft chain length is much shorted than that of homopolymer chain in the melt.…”

Section: The Graft Copolymerization and Homopolymerizationsupporting

confidence: 76%

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: The Graft Copolymerization and Homopolymerizationsupporting

confidence: 76%

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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show abstract

“…The effect of the monomer and peroxide initiator concentrations on the grafting process qualitatively agrees with that observed in other systems. For example, when the concentration of both the peroxide initiator and monomer increases, the amount of the grafted polar monomer increases, whereas the grafting efficiency slightly decreases during the modification of PE with acrylic acid (and its ester derivatives)19 and 2‐(dimethylamino)ethyl methacrylate 10…”

Section: Resultsmentioning

confidence: 99%

“…To improve these properties, it has been chemically modified with a vast variety of polar monomers. Some of the most commonly used modifiers are acrylic acid and esters; maleic anhydride and its analogues, such as fumaric acid and itaconic acid; and dimethylaminoethyl methacrylate and diethyl maleate 1–11…”

Section: Introductionmentioning

confidence: 99%

Melt grafting of N‐carbamyl maleamic acid onto linear low‐density polyethylene

Ciolino

Failla

Vallés

2002

J. Polym. Sci. A Polym. Chem.

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The grafting of N‐carbamyl maleamic acid (NCMA) onto linear low‐density polyethylene (LLDPE) was carried out with different concentrations of 2,5‐dimethyl‐2,5‐di(tert‐butylperoxy) hexane (DBPH) as an initiator. The modification process was performed in the molten state with a Brabender mixer. All the materials were characterized with Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry, and melt rheology. The analysis of the FTIR spectra indicated that the grafting efficiency increased with the concentration of both NCMA and DBPH. The calorimetric experiments showed that the modification process did not noticeably alter the enthalpy of fusion of LLDPE, whereas the melting temperature of the modified polymers was slightly lower than that corresponding to the original LLDPE. The rheological response of the molten polymers, determined under dynamic shear flow at small‐amplitude oscillations, indicated that the modification process induced crosslinking of the chains. Both the dynamic viscosity and elastic modulus of the modified LLDPE increased with the concentration of NCMA and DBPH, showing that larger molecules were generated during the modification process. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3950–3958, 2002

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“…However, the occurrence of homopolymerization can be controlled by varying processing parameters such as temperature, co‐agent structure, feed concentration and residence time. Song and Baker developed the kinetic rate expressions for grafting and homopolymerization and explored conditions for maximizing grafting and minimizing homopolymerization for the grafting of dimethylaminoethyl methacrylate (DMAEMA) onto polyethylene (PE) in an intermeshing co‐rotating twin‐screw extruder . Cha and White discussed the competition between the grafting and homopolymerization for the grafting of styrene onto polypropylene (PP).…”

Section: Introductionmentioning

confidence: 99%

Kinetic study on free radical grafting of polyethylene with acrylic acid by reactive extrusion

Zhang

Jia

2014

J of Applied Polymer Sci

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In the reactive extrusion process for the free radical grafting of acid monomers onto polyethylene, monomer grafting and homopolymerization occur simultaneously and interact with each other. Using an incremental theory, mathematical models of conversions for monomer grafting and homopolymerization were separately constructed to predict the grafting degree, mass of homopolymer and grafting efficiency. Effects of the barrel temperature, initial monomer and initiator concentrations on grafting behaviors were investigated. The barrel temperature and initial monomer concentration were shown to be the main process parameters for controlling the grafting degree. The grafting degree and mass of homopolymer increased significantly with increasing barrel temperature and monomer concentration and increased marginally with increasing initiator concentration. No significant improvement in the grafting efficiency was observed. The predictions of the models are in good agreement with experimental data. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40990.

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Melt grafting of a basic monomer on to polyethylene in a twin-screw extruder: reaction kinetics

Cited by 33 publications

References 9 publications

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

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

Melt grafting of N‐carbamyl maleamic acid onto linear low‐density polyethylene

Kinetic study on free radical grafting of polyethylene with acrylic acid by reactive extrusion

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