Melt rheology of graft modified polypropylene

Wong, Betty; Baker, W. E.

doi:10.1016/s0032-3861(97)85615-7

Cited by 83 publications

(66 citation statements)

References 24 publications

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“…This has been previously observed for samples taken from the extrudate and was related to the grafting of MA onto PP. 29 Other studies have shown similar phenomena simply attributed to competition between MA grafting onto PP and ␤ scission. This explanation seems rather superficial because grafting does not result in the loss of free-radical species susceptible to degradation.…”

Section: Effect Of the Polyolefin Structure On Graftingmentioning

confidence: 74%

Monitoring polyolefin modification along the axis of a twin-screw extruder. II. Maleic anhydride grafting

Machado

Duin

Covas

2000

J. Polym. Sci. A Polym. Chem.

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Section: Effect Of the Polyolefin Structure On Graftingmentioning

confidence: 74%

Monitoring polyolefin modification along the axis of a twin-screw extruder. II. Maleic anhydride grafting

Machado

Duin

Covas

2000

J. Polym. Sci. A Polym. Chem.

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“…Due to the chemical nature of PP, it has a tendency to undergo ␤-scission under a presence of radicals. This causes a decrease of the molecular weight 6,23 so that an increase of MFR and a decrease of GЈ, *, and E(linear) are reasonable (see Table I and Fig. 1-3).…”

Section: Effect Of Electron Beam Irradiationmentioning

confidence: 79%

Effect of chain structure on the melt rheology of modified polypropylene

Sugimoto

Tanaka

Masubuchi

et al. 1999

J. Appl. Polym. Sci.

103

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ABSTRACT:The effect of molecular structure of polypropylene (PP) on the melt rheological properties were investigated for electron irradiated polymer and di-2-ethylhexyl peroxy dicarbonate (EHPC)-treated polymer. The modifications were examined in terms of the rheological behaviors, molecular weight distribution, and the degree of branching. The high melt strength PP was obtained by irradiating with 50 and 80 kGy and adding EHPC. The modified PPs showed the strain hardening in the uniaxial elongational viscosity, though the linear elongational viscosity was lower than that of the unmodified PP. Low angle laser light-scattering measurements of the modified PPs showed the interesting results; high irradiation doses such as 50 and 80 kGy caused higher molecular weight chains branching. Nevertheless, the long branching chains were not detected for the EHPC modified PP, which also showed the strain hardening in uniaxial elongational flow. In this article, the relation between chain structure and rheological properties is discussed.

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“…The marked increase in torque observed for PA6/LDPE 75/25 with 10 phr LDPE-g-GMA suggests that the occurrence of crosslinking reactions between the grafted chains (via epoxide groups) in the melt should also be taken into account at high contents of compatibilizer. [26,27] Blends with an LDPE matrix compatibilized with SEBSg-GMA presented a torque variation similar to that found for 25/75 blends with LDPE-g-GMA (molar ratio [NH 2 þCOOH]/[GMA] g ¼ 1.15 for PA6/LDPE/SEBS-g- GMA 25/75/5), while for blends with a PA6 matrix a significant increase in torque occurred up to a SEBS-g-GMA content of 5 phr (molar ratio [NH 2 þCOOH]/[GMA] g ¼ 3.35), which corresponds to a very fine dispersion of polyolefin particles. Higher amounts of this compatibilizer did not cause further changes in torque or phase dispersion, as revealed by microscopic analysis.…”

Section: Melt Rheologymentioning

confidence: 99%

Reactive Compatibilization of PA6/LDPE Blends with Glycidyl Methacrylate Functionalized Polyolefins

Qian

Chionna²,

Pracellà³

2005

Macro Chemistry & Physics

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Summary: Blends of polyamide‐6 (PA6) and low density polyethylene (LDPE) were compatibilized by melt mixing with various polyolefins functionalized with glycidyl methacrylate (GMA), i.e., GMA grafted LDPE (LDPE‐g‐GMA), GMA grafted styrene‐ethylene/butylene‐styrene block copolymer (SEBS‐g‐GMA) and ethylene‐co‐glycidyl methacrylate copolymer (E‐GMA). Blends with PA6/LDPE composition ratios of 25/75 and 75/25 wt.‐%/wt.‐% were prepared in a Brabender internal mixer and their properties were evaluated by SEM, rheological measurements and DSC. Morphological investigation by SEM showed a neat improvement of phase dispersion and interfacial adhesion in all compatibilized blends when compared to PA6/LDPE binary blends. The variation of the dispersed phase size was analyzed as a function of blend composition, compatibilizer concentration and GMA content. The emulsification curves of compatibilized blends showed that the equilibrium size of dispersed particles at the saturation concentration of copolymer was lower when PA6 was the major component. The finest dispersion of the LDPE phase (<0.25 μm) was observed in the presence of SEBS‐g‐GMA copolymer. LDPE‐g‐GMA and E‐GMA displayed a similar compatibilizing efficiency. In all cases, the blends with a polyamide matrix presented a marked rise in torque and melt viscosity with increasing compatibilizer content. These effects were accounted for by a reaction between the epoxide groups of LDPE‐g‐GMA and the carboxyl/amine end‐groups of PA6, leading to the formation of an interchain graft copolymer. The phase transition processes of PA6 in the blends were influenced by the compatibilizer content and the interfacial interactions between the polymer components, suggesting a different role for the compatibilizer at the PA6/LDPE interface.SEM micrograph of PA6/LDPE 25/75 blend compatibilized with 2.5 phr SEBS‐g‐GMA.magnified imageSEM micrograph of PA6/LDPE 25/75 blend compatibilized with 2.5 phr SEBS‐g‐GMA.

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Melt rheology of graft modified polypropylene

Cited by 83 publications

References 24 publications

Monitoring polyolefin modification along the axis of a twin-screw extruder. II. Maleic anhydride grafting

Monitoring polyolefin modification along the axis of a twin-screw extruder. II. Maleic anhydride grafting

Effect of chain structure on the melt rheology of modified polypropylene

Reactive Compatibilization of PA6/LDPE Blends with Glycidyl Methacrylate Functionalized Polyolefins

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