Basic Concepts in Polymer Melt Rheology and Their Importance in Processing

Vlachopoulos, J.; Polychronopoulos, Nickolas D.

doi:10.1002/9781118140611.ch1

Cited by 34 publications

(39 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…As explained for Fig. c, G′ is highly sensitive to PD due to the more important contribution of the tail of the high M w polymer chains to the elasticity of the polymer . As depicted in Fig.…”

Section: Resultsmentioning

confidence: 86%

See 1 more Smart Citation

Solid‐state polymerization of poly(ethylene terephthalate): Effect of organoclay concentration

Dini

Carreau

Kamal

et al. 2014

Polymer Engineering & Sci

View full text Add to dashboard Cite

Poly(ethylene terephthalate) (PET)/Cloisite 30B (C30B) nanocomposites of different organoclay concentrations were prepared using a water-assisted extrusion process. The reduction of the molecular weight (M w ) of the PET matrix, caused by hydrolysis during water-assisted extrusion, was compensated by subsequent solid-state polymerization (SSP). Viscometry, titration, rheological, and dynamic scanning calorimetry measurements were used to analyze the samples from SSP. The weight-average molecular weight (M w ) of PET increased significantly through SSP. PET nanocomposites exhibited solid-like rheological behavior, and the complex viscosity at high frequencies was scaled with the M w of PET. The Maron-Pierce model was used to evaluate the M w of PET in the nanocomposites before and after SSP. It was found that the extent and the rate of the SSP reaction in nanocomposites were lower than those for the neat PETs, due to the barrier effect of clay platelets. Consequently, the SSP rate of PET increased with decreasing particle size for the neat PET and PET nanocomposites. The effect of the M w of PET on the crystallization temperature, crystallinity, and the half-time, t1 =2 , of nonisothermal crystallization was also investigated. With increasing M w of PET, t1 =2 increased, whereas T c and X c decreased. POLYM. ENG. SCI., 54:2925-2937

show abstract

Section: Resultsmentioning

confidence: 86%

“…All PET data are superimposed on each other, except those of the PET before SSP (S‐0), which exhibit very low G′ values. Generally, at the same M w , polymers with larger PD show higher G′ as the high molecular chains contribute significantly to the elastic modulus . Hence, the narrower PD PET exhibits a lower G′ .…”

Section: Resultsmentioning

confidence: 97%

Solid‐state polymerization of poly(ethylene terephthalate): Effect of organoclay concentration

Dini

Carreau

Kamal

et al. 2014

Polymer Engineering & Sci

View full text Add to dashboard Cite

show abstract

“…In addition to tan(

) plots indicating higher or lower elasticity, the performance of extensional rheology tests is a suitable method to get information about improved resistance of a polymer melt towards elongation before rupture which is referred to as strain hardening behavior [ 55 ].…”

Section: Results and Discussionmentioning

confidence: 99%

Effect of Different Compatibilization Systems on the Rheological, Mechanical and Morphological Properties of Polypropylene/Polystyrene Blends

Seier¹,

Stanic²,

Koch³

et al. 2020

Polymers

View full text Add to dashboard Cite

The influence of reactive processing, non reactive and reactive copolymers on immiscible polypropylene (PP)–polystyrene (PS) blends with varying PS concentrations (10 wt.% and 25 wt.%) was evaluated by mechanical (tensile and tensile impact), rheological (melt flow rate, extensional and dynamic rheology) and morphological (scanning electron microscopy) analysis. As an extended framework of the study, the creation of a link to industrial applicable processing conditions as well as an economically efficient use of compatibilzing agent were considered. For radical processed blends, a high improvement in melt strength was observed while non reactive copolymers exhibited a pronounced increase in toughness and ductility correlated with overall best phase homogeneity. Conversely, the influence of the reactive copolymer was quite different for the varied PS concentrations not allowing the assumption of a specific trend for resulting blend properties, but nevertheless in the case of a lower PS concentration the tensile impact strength exceeded the value of virgin PP. Since PS and PP are widely used, the findings of this work could not only be relevant for the generation of more versatile blends compared to virgin components but also for recycling purposes, allowing the enhancement of specific properties facilitating the production of more valuable secondary materials.

show abstract

“…A high shear rate flow of the order of 10 4 s À1 can occur at this location. 104 At process temperatures and at this level of shear rate, the viscosity is up to 100 Pa s, producing a coupling stress of 10 5 Pa.…”

Section: Polymer Melt Processes: Injection Moldingmentioning

confidence: 97%

“…Shear rates of 10 3 s À1 , so tensile strain rates of 10 2 s À1 , can be present. 104 The shear viscosity at these levels of shear rate, and at extrusion temperature, can vary between 100 and 1,000 Pa s. A coupling stress of 10 5 Pa could theoretically be achieved in this process.…”

Section: Polymer Melt Processes: Extrusionmentioning

confidence: 98%

Polymer Mechanochemistry: Manufacturing Is Now a Force to Be Reckoned With

Willis‐Fox

Rognin

Aljohani

et al. 2018

Chem

176

143

View full text Add to dashboard Cite

Polymer mechanochemistry is an exciting, rapidly developing field; however, it lacks detailed studies on the link between lab-scale mechanical activation and how the chemistry will translate to the complex flows and forces experienced during fluid-based molding and additive manufacturing techniques. This is especially important for polymers, which are the functional material of choice for applications such as organic electronics, biological scaffolds, and drug-delivery coatings, because there is the highest likelihood of mechanical activation. This review examines the most recent development in force-sensitive molecules known as mechanophores by re-categorizing them by material phase and method of activation and discussing the forces involved in such flow systems and where activation may occur in relevant manufacturing processes. The overall finding of this review is that for real, practical, and scalable industrial applications of these exciting mechanochemical materials, there must be a concurrent study of the forces experienced and their effect on the detailed chemistry.

show abstract

Basic Concepts in Polymer Melt Rheology and Their Importance in Processing

Cited by 34 publications

References 18 publications

Solid‐state polymerization of poly(ethylene terephthalate): Effect of organoclay concentration

Solid‐state polymerization of poly(ethylene terephthalate): Effect of organoclay concentration

Effect of Different Compatibilization Systems on the Rheological, Mechanical and Morphological Properties of Polypropylene/Polystyrene Blends

Polymer Mechanochemistry: Manufacturing Is Now a Force to Be Reckoned With

Contact Info

Product

Resources

About