Factors affecting extrudate swell and melt flow rate

Wong, A. C.-Y.

doi:10.1016/s0924-0136(98)00006-5

Cited by 14 publications

(7 citation statements)

References 2 publications

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“…We can only compare the relative value of the viscosity among polymers with the same structure. [15][16][17] Compared with MFR instrument in a single test condition, the capillary rheometer with wide measuring range expresses melt viscosity and mobility under different shear rates, which is more comprehensive. [18][19][20] Apparent shear viscosity compared with apparent shear rate for PEEK mixed with different content of KMnO 4 at 400 C was displayed in Figure 2.…”

Section: Rheological Performance From Capillary Rheometermentioning

confidence: 99%

The effects of manganese ions on rheology and thermal properties of polyether ether ketone

Wang

Dang

et al. 2016

High Performance Polymers

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Polyether ether ketone (PEEK) mixed with manganese (Mn) of different valences was prepared to simulate conditions of impurity. The melt flow rate (MFR) and rheological behaviour were systematically studied to characterize the mobility from different angles. MFR test was used for the preliminary exploration of mixtures of Mn ions. The results showed that Mn, Mn(II), and Mn(IV) had little impact on the mobility of PEEK contrary to Mn(VII) and that long chain branching or cross-linking was suspected. Mn(VII) was determined to be the main object of this research. Capillary rheometer test demonstrated that the apparent shear viscosity constantly reduced with the increase of apparent shear rate, and that the addition of Mn(VII) could worsen the mobility of PEEK. Similarly, parallel plate rheometer studies proved that the complex viscosity increased along with the content of Mn(VII) and LCB was confirmed. Thermal analysis revealed that LCB occurred internally and that thermal stability was worse.

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Section: Rheological Performance From Capillary Rheometermentioning

confidence: 99%

The effects of manganese ions on rheology and thermal properties of polyether ether ketone

Wang

Dang

et al. 2016

High Performance Polymers

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“…It is an entropy‐driven phenomenon that occurs when the individual polymer chains, due to their viscoelastic properties, recover from the deformation caused by the rotating screw inside the barrel, by relaxing and increasing their cross section. The extent of ‘extrudate swell’ depends as well on external factors as on factors intrinsic to the polymer …”

Section: Process and Equipmentmentioning

confidence: 99%

“…The extent of 'extrudate swell' depends as well on external factors as on factors intrinsic to the polymer. [29] The other exit phenomenon, 'sharkskin' , is an extrudate surface defect characterized by small scale and high frequency roughness. Two possible explanations for its occurrence have been suggested.…”

Section: Multi-manifoldmentioning

confidence: 99%

Hot-melt co-extrusion: requirements, challenges and opportunities for pharmaceutical applications

Vynckier

Dierickx

Voorspoels³

et al. 2014

Journal of Pharmacy and Pharmacology

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Objectives Co-extrusion implies the simultaneous hot-melt extrusion of two or more materials through the same die, creating a multi-layered extrudate. It is an innovative continuous production technology that offers numerous advantages over traditional pharmaceutical processing techniques. This review provides an overview of the co-extrusion equipment, material requirements and medical and pharmaceutical applications. Key findings The co-extrusion equipment needed for pharmaceutical production has been summarized. Because the geometrical design of the die dictates the shape of the final product, different die types have been discussed. As one of the major challenges at the moment is shaping the final product in a continuous way, an overview of downstream solutions for processing co-extrudates into drug products is provided. Layer adhesion, extrusion temperature and viscosity matching are pointed out as most important requirements for material selection. Examples of medical and pharmaceutical applications are presented and some recent findings considering the production of oral drug delivery systems have been summarized. Summary Co-extrusion provides great potential for the continuous production of fixed-dose combination products which are gaining importance in pharmaceutical industry. There are still some barriers to the implementation of co-extrusion in the pharmaceutical industry. The optimization of downstream processing remains a point of attention.

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“…167 Krivoguz et al -eXPRESS Polymer Letters Vol.4, No.3 (2010) 161-170 It should be noted, that despite regular studies carried out for many years, the accumulated information on swelling mechanisms and strength of polymer melts mostly refers to virgin PO and their blends [32][33][34][35][36][37][38]. Little information is available on functionalized PO.…”

Section: High-elastic Properties Of Pe-g-teda Meltsmentioning

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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Factors affecting extrudate swell and melt flow rate

Cited by 14 publications

References 2 publications

The effects of manganese ions on rheology and thermal properties of polyether ether ketone

The effects of manganese ions on rheology and thermal properties of polyether ether ketone

Hot-melt co-extrusion: requirements, challenges and opportunities for pharmaceutical applications

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

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