Fracture of ultrafine fibers in the flow of mixtures of non-newtonian polymer melts

Цебренко, М. В.; Danilova, G.P.; Malkin, A. Ya.

doi:10.1016/0377-0257(89)80011-4

Cited by 47 publications

(19 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A number of publications deal with the influence of volume fraction of the dispersed phase on polymer blend rheology, drop size and stability, namely, Van Oene [58], Utracki [59], Favis and Chalifoux [60] and Chen et al [61]. The above mentioned topics have been summarised in a number of recent books and reviews [1,41,[62][63][64][65][66].…”

Section: The Role Of Coalescencementioning

confidence: 99%

Rheology of polymer blends

Lyngaae-Jørgensen¹

1993

Polymer Blends and Alloys

View full text Add to dashboard Cite

Polymer blend (PB). A mixture of at least two polymers or copolymers.Miscible PB. PB homogeneous down to molecular level: !lG m ~ !lH m ~ O.Compatible PB (Utilitarian term). Homogeneous to the eye, commercially attractive PB.Polymer alloy (P A). Immiscible PB having a modified interface and/or morphology.Polymer materials may be grouped in different ways. An overview of the most common two-phase systems consisting of polymers is shown in Figure 4.1. This chapter deals mainly with melt flow properties of physical mixtures of different polymers. The rheology of block copolymers is reviewed in [2]. Rheology is the science of the deformation and flow of materials. For polymers there may be at least three distinct objectives of rheological work: (a) To develop fundamental understanding of material behaviour in order to develop rheological equations of state. (b) To use the simplest possible laboratory investigations in order to find relationships with processing practice in order to govern and predict processing properties of polymer materials. (c) To develop relationships between measures of polymer structure and properties, in this case rheological properties. If such relationships have been established, rheological data can be used for characterisation of, say, average molecular weight, determination of branching in polymers, etc. The establishment of valid rheological equations is an active research field. A very large body of possible rheological equations has been established M. J. Folkes et al. (eds.), Polymer Blends and Alloys

show abstract

Section: The Role Of Coalescencementioning

confidence: 99%

Rheology of polymer blends

Lyngaae-Jørgensen¹

1993

Polymer Blends and Alloys

View full text Add to dashboard Cite

show abstract

“…80 Other authors have examined bril formation in the converging die entrance and found droplet coalescence to occur there. 30,80,81 In brief, in the case of the present study, the combined effect of deformation and coalescence leads to brillation of the PA11 dispersed phase droplets in viscoelastic PLA matrix modied by the ( CE [.…”

Section: Morphology Of the Blends In The Extrudatementioning

confidence: 99%

Development of nanofibrillar morphologies in poly(l-lactide)/poly(amide) blends: role of the matrix elasticity and identification of the critical shear rate for the nodular/fibrillar transition

et al. 2018

View full text Add to dashboard Cite

Bio-based poly(L-lactide)/poly(amide-11) blends (PLA/PA11, 80/20 w/w) and poly(L-lactide)/poly(amide-6) blends (PLA/PA6, 80/20 w/w) are processed by twin-screw extrusion followed by injection-moulding and key rheological parameters controlling their morphologie are investigated. The same work is done using the same PLA modified by a multi-step reactive extrusion route with an epoxy-based chain extender to obtain modified poly(lactide)/poly(amide-11) (PLA-j/PA11 80/20 w/w) blends. The morphologies of the extruded materials and of the injection moulded parts are characterized by SEM and their formation is deeply discussed via rheological investigation to highlight the contribution of viscosity, elasticity and interfacial tension. The existence of a critical shear rate related to the transition from nodular to fibrillar morphology is highlighted and the results are in good agreement with the condition of fibrillation Ca/Ca (crit) $ 4. Interestingly, with the exception of PLA/PA6 specimens, all blends obviously display uniform thin-thread fibrillar morphologies after injection-moulding. Compared with pure PLA, a drastic increase of the ductility was observed in the blends exhibiting a fiberlike structure without meanwhile sacrificing the stiffness. This study confirms that, through the appropriate choice of blend components (viscosity and elasticity ratio, flow conditions, interfacial tensions) the in situ fibrillation concept provides access, at a reasonable cost, to new materials with improved thermomechanical performances, without sacrificing weight and ability to be recycled.

show abstract

“…The former is the result of droplet deformation arising from the viscous drag force exerted on the droplets by the matrix exceeding the interfacial tension between two phases, while the latter results from the impingement of droplets because of the intrinsic normal force of viscoelastic droplets. The deformation and break-up of the droplets are controlled by two parameters: [11] the viscosity ratio of the dispersed phase to matrix, R v ¼ Z d /Z m , and the so-called Weber number, N w ¼ rZ m g/s ¼ rt/s, where r is radius of droplet, g is the shear rate, t is the shear stress, and s is the interfacial tension. When R v resides in an appropriate range and N w surmounts a certain critical value, droplets can deform and break-up, but it is not the case otherwise.…”

Section: Resultsmentioning

confidence: 99%

“…Furthermore, the fibers (liquid streams) formed may exhibit capillary wave (varicosity) phenomena on account of the hydrodynamic disturbance arising from the fluctuation of melt density and viscosity or the vibration of the equipment. [11] Once the amplitude of such waves exceeds the radius of the fiber, the liquid stream will break up into droplets. The probability of such an action will scale up with f w because of the increased number of fibers.…”

Section: Resultsmentioning

confidence: 99%

In‐Situ Fiberized Poly(ethylene terephthalate) as a Reinforcement to Poly(propylene) Matrix

Shen

Huang

Sheng-wu

2003

Macro Materials & Eng

View full text Add to dashboard Cite

The reinforced poly(propylene) (PP)/poly(ethylene terephthalate) (PET) in‐situ fiberized composites were prepared by extrusion‐drawing‐injection molding. The influences of PET weight fraction (fw) on the PET fiberization, phase morphology, and mechanical properties of the composites, together with their functional mechanisms were studied by contrast to the normal‐blended materials without drawing. The results show that as the fw rises from 0 to 20%, the number of PET fibers increases, whereas their diameter and dispersity decrease till fw = 15% and then increase, and the number of remained PET particles tends to rise. These changes of PET fiberization and phase morphology with fw were attributed to the consequence of the combined actions of breakup, coalescence, and deformation of the PET dispersed phase in the PP matrix during the extrusion drawing. Correspondingly, the tensile strength (σt) and Young's modulus (E) of the in‐situ composites increase till fw = 15% and then decrease, with maximum gains of σt and E of about 20 and 70% relative to the neat PP, respectively. This σt/fw relation was ascribed to the counterbalanced result between the reinforcing effect of the dispersed phase on matrix and the interfacial flaw effect of two immiscible phases, while the E/fw relation was considered as a representation of the rigidizing effect of the fibers on the matrix being controlled by both their number and diameter.In‐situ PET fibres (PET/PP = 85/15) in an as‐drawn filament.magnified imageIn‐situ PET fibres (PET/PP = 85/15) in an as‐drawn filament.

show abstract

Fracture of ultrafine fibers in the flow of mixtures of non-newtonian polymer melts

Cited by 47 publications

References 30 publications

Rheology of polymer blends

Rheology of polymer blends

Development of nanofibrillar morphologies in poly(l-lactide)/poly(amide) blends: role of the matrix elasticity and identification of the critical shear rate for the nodular/fibrillar transition

In‐Situ Fiberized Poly(ethylene terephthalate) as a Reinforcement to Poly(propylene) Matrix

Contact Info

Product

Resources

About