An experimental investigation of interfacial instabilities in multilayer flow of viscoelastic fluids. Part II. Elastic and nonlinear effects in incompatible polymer systems

Wilson, Gregory M.; Khomami, Bamin

doi:10.1122/1.550445

Cited by 74 publications

(34 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, very comprehensive experiments have been carried out by Wilson and Khomami on both miscible and immiscible fluids [20,21]. Their facilities introduce temporally regular disturbances with controllable amplitudes and frequencies.…”

Section: Introductionmentioning

confidence: 99%

Role of the interphase in the flow stability of reactive coextruded multilayer polymers

Lamnawar

Maazouz

2009

Polymer Engineering & Sci

View full text Add to dashboard Cite

Coextrusion technologies are commonly used to produce multilayered composite sheets or films for a large range of applications from food packaging to optics. The contrast of rheological properties between layers can lead to interfacial instabilities. Important theoretical and experimental advances regarding theses defects have, during the last decades, been made using a mechanical and numerical approach. This study deals with the influence of the physicochemical affinity between the neighboring layers on interfacial instabilities for functionalized incompatible polymers. It was experimentally confirmed, in this case, that weak disturbance can be predicted by considering an interface of nonzero thickness (corresponding to an interdiffusion/reaction zone interphase) instead of a purely geometrical interface between the two reactive layers. According to the rheological investigations, an experimental strategy was here formulated to investigate the parameters that controlled the stability of the reactive multilayer flows. The role of the viscosity ratio, elasticity ratio, and layer ratio of the stability of the interface was also investigated coupling to the reaction rate/compatibilization phenomenon. Hence, based on this analysis, guidelines for a stable coextrusion of reactive functionalized polymers can be provided coupling the classical parameters and the physicochemical affinity at the polymer/polymer interface. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers

show abstract

Section: Introductionmentioning

confidence: 99%

Role of the interphase in the flow stability of reactive coextruded multilayer polymers

Lamnawar

Maazouz

2009

Polymer Engineering & Sci

View full text Add to dashboard Cite

show abstract

“…In recent years some experimental studies have addressed the problem of interfacial viscoelastic stability. Wilson and Khomami [31] examined instability in multilayer flow of viscoelastic fluids experimentally to determine stability and growth rate plots as a function of the disturbance wavenumber and the layer depth ratio. Saasen et al [32] attempted to use linear wave theories for non-Newtonian fluids in canal experiments to determine the rheological parameters of the fluids.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear surface wave instability for electrified Kelvin fluids

El‐Dib

2005

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

“…The studies also demonstrated that the interfacial stability of multilayer flows was determined by a number of factors that were either essential (e.g., thickness, viscosity and elasticity ratios) or rather uninfluential (e.g., density ratios and interfacial tensions). Very comprehensive experiments have been carried out by Wilson and Khomami on both miscible and immiscible fluids [13][14]. Their facilities introducie temporally regular disturbances with controllable amplitudes and frequencies.…”

mentioning

confidence: 99%

Reactive Functionalized Multilayer Polymers in a Coextrusion Process: Experimental and Theoretical Investigations of Interfacial Instabilities

2008

View full text Add to dashboard Cite

International audienceCoextrusion technologies are commonly used to produce multilayered composite sheets or films for a large range of applications from food packaging to optics. The contrast of rheological properties between layers can lead to interfacial instabilities during flow. Important theoretical and experimental advances regarding the stability of compatible and incompatible polymers have, during the last decades, been made using a mechanical approach. However, few research efforts have been dedicated to the physicochemical affinity between the neighboring layers. The present study deals with the influence of this affinity on interfacial instabilities for functionalized incompatible polymers. Polyamide (PA6)/polyethylene grafted with glycidyl methacrylate (PE-GMA) was used as a reactive system and PE/PA6 as a non reactive one. Two grades of polyamide (PA6) were used in order to change the viscosity and elasticity ratios between PE (or PE-GMA) and PA6. It was experimentally confirmed, in this case, that weak disturbance can be predicted by considering an interphase of non-zero thickness (corresponding to an interdiffusion/reaction zone) instead of a purely geometrical interface between the two reactive layers. According to rheological investigations from previous work, an experimental strategy was here formulated to optimize the process by listing the parameters that controlled the stability of the reactive multilayer flows. Plastic films with two layers were coextruded in symmetrical and asymmetrical configurations in which PA6 was the middle layer. Indeed, for reactive multilayered systems, the interfacial flow instability could be reduced or eliminated, for instance, by (i) increasing the residence time or temperature in the coextrusion bloc (for T above the reaction temperature T = 240°C), and (ii) reducing the total extrusion flow rate. The reaction rate/compatibilization played a major role that must be taken into account. Furthermore, the role of the viscosity ratio, elasticity ratio, and layer ratio of the stability of the interface were also investigated coupling to the physicochemical affinity. The results show that it is necessary to obtain links between the classic factors that are introduced in the evaluation of the theoretical, given by linear stability analysis/longwave asymptotic investigations, and its corresponding experimental stability charts. Hence, based on this analysis, guide-lines for a stable coextrusion of reactive functionalized polymers can be provided

show abstract

An experimental investigation of interfacial instabilities in multilayer flow of viscoelastic fluids. Part II. Elastic and nonlinear effects in incompatible polymer systems

Cited by 74 publications

References 18 publications

Role of the interphase in the flow stability of reactive coextruded multilayer polymers

Role of the interphase in the flow stability of reactive coextruded multilayer polymers

Nonlinear surface wave instability for electrified Kelvin fluids

Reactive Functionalized Multilayer Polymers in a Coextrusion Process: Experimental and Theoretical Investigations of Interfacial Instabilities

Contact Info

Product

Resources

About