Free-radical grafting of itaconic acid onto LDPE by reactive extrusion: I. Effect of initiator solubility

Песецкий, С. С.; Jurkowski, B.; Krivoguz, Yu. M.; Kelar, K.

doi:10.1016/s0032-3861(00)00356-6

Cited by 40 publications

(42 citation statements)

References 6 publications

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“…The tert-butoxy radicals can further split to create more reactive methyl radicals (•CH 3 ) under the high grafting temperature, as shown in Figure 1. Both types of reactive free radicals formed in the system [24] can initiate the grafting reaction on the NR which may proceed through two different pathways via H-abstraction and addition [25], as shown in Figure 2. The reactive initiator transfers its radical to the sulfur on the coupling agent which subsequently attacks a double bond of the polymer molecule.…”

Section: Results and Discussion 31 Grafting Of Nxt Onto Nr Moleculesmentioning

confidence: 99%

Silane grafted natural rubber and its compatibilization effect on silica-reinforced rubber tire compounds

Sengloyluan¹,

Sahakaro²,

Dierkes³

et al. 2017

Express Polym. Lett.

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Abstract. Natural Rubber (NR) grafted with 3-octanoylthio-1-propyltriethoxysilane (NXT) was prepared by melt mixing using 1,1′-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane as initiator at 140°C with NXT contents of 10 and 20 parts per hundred rubber [phr] and initiator 0.1 phr. The silane grafted on NR molecules was confirmed by Fourier transform infrared (FTIR), proton nuclear magnetic resonance ( 1 H-NMR) and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM-EDX). Based on 1 H-NMR, the use of 10 and 20 phr (parts per hundred resin) of silane resulted in grafted NXT onto NR of 0.66 and 1.32 mol%, respectively, or a grafting efficiency of approx.38%. The use of NXT-grafted NR as compatibilizer in silica-filled NR compounds, to give a total amount of NXT in both grafted and non-grafted forms in the range of 0.8-6.1 wt% relative to the silica, decreases the Mooney viscosity and Payne effect of the compounds, improves filler-rubber interaction, and significantly increases the tensile properties of the silica-filled NR-compounds compared to the non-compatibilized one. At the same silane-content, the use of silane-grafted NR gives slightly better properties than the straight use of the same silane. With sulfur compensation, the use of NXT-grafted-NR with about 6 wt% NXT relative to the silica gives technical properties that reach the levels obtained for straight use of bis-(3-triethoxysilyl-propyl)tetrasulfide (TESPT) at 8.6 wt% relative to the silica.

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Section: Results and Discussion 31 Grafting Of Nxt Onto Nr Moleculesmentioning

confidence: 99%

Silane grafted natural rubber and its compatibilization effect on silica-reinforced rubber tire compounds

Sengloyluan¹,

Sahakaro²,

Dierkes³

et al. 2017

Express Polym. Lett.

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“…Thus in addition to k d , the miscibility of the initiator and radicals generated from it with the polymer phase is of key importance. Pesetskii et al investigated the grafting of itaconic acid onto PE and found that initiator solubility effects were more important than k d values [37] . Furthermore, free -radical inhibitors soluble in polyethylene but insoluble in itaconic acid inhibited crosslinking but did not signifi cantly affect grafting [38] .…”

Section: Effect Of the Initiatormentioning

confidence: 99%

“…Monomers that readily homopolymerize will encourage grafting over crosslinking, and are more likely to generate signifi cant amounts of homopolymer (e.g., butyl acrylate); monomers that are reluctant to homopropagate will give short grafts and may enhance crosslinking (e.g., ethyl maleate) [37,48] .…”

Section: Effect Of the Monomermentioning

confidence: 99%

Mechanism and Kinetics

Fellows

2008

Polymer Grafting and Crosslinking

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“…It has been learned that saturated PO functionalization by grafting polar monomers onto their macromolecules in melt and grafted product output depends on the nature of reactants (polymer, initiator of radical reactions, monomer to be grafted), composition of the reacting system and on a set of technological factors of which melt temperature, reaction period, degree of shear effect upon the melt are most important [16,19,20]. It is believed that at monomer grafting onto saturated PO, the free radicals, formed as a result of initiator decomposition, break away mobile hydrogen from macromolecules, while macroradicals formed interact with monomers making them grafted [18,21]. There has been found a difference in the mechanisms and kinetics of side reactions during PE and PP functionalization: PE macromolecules undergo crosslinking for the most part, while PP macromolecules suffer degradation owing to β-decomposition of macroradicals which are formed at interaction with the initiator.…”

Section: Introductionmentioning

confidence: 99%

Functionalization of LDPE and mLLDPE via grafting trans-ethylene-1,2-dicarboxylic acid by reactive extrusion

Krivoguz¹,

Guliyev²,

Песецкий³

2010

Express Polym. Lett.

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Abstract. An investigation was made of grafting trans-ethylene-1,2-dicarboxylic acid (TEDA) onto metallocene-linear low-density polyethylene (mLLDPE) and low-density polyethylene (LDPE) in the course of reactive extrusion. The initiator was 1,3-bis-(tert-butyl-peroxyisopropyl)benzene. The graft efficiency of TEDA has been shown to increase with increasing initiator concentration, irrespective of polyethylene type. The graft values for LDPE were higher than for mLLDPE over the initiator concentration range (0.05 to 0.4 wt%). The rheological properties of mLLDPE were found to undergo more tangible changes during functionalization than those of LDPE. These changes were caused by side reactions, mainly macromolecular crosslinking. It has been established that some carboxyl groups get transformed to anhydride groups in the grafted product. The concentration of end double bonds reduces, but intramolecular unsaturation in both polyethylenes increases. Data are presented on thermal and stress-strain (mechanical) properties of virgin and functionalized polymers, as well as rheological and viscoelastic properties of their melts.

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Free-radical grafting of itaconic acid onto LDPE by reactive extrusion: I. Effect of initiator solubility

Cited by 40 publications

References 6 publications

Silane grafted natural rubber and its compatibilization effect on silica-reinforced rubber tire compounds

Silane grafted natural rubber and its compatibilization effect on silica-reinforced rubber tire compounds

Mechanism and Kinetics

Functionalization of LDPE and mLLDPE via grafting trans-ethylene-1,2-dicarboxylic acid by reactive extrusion

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