Evaluation of the influence of testing parameters on the melt flow index of thermoplastics

Guerreiro, Sérgio D.C.; Joao, Isabel M.; Real, L.E. Pimentel

doi:10.1016/j.polymertesting.2012.07.008

Cited by 23 publications

(12 citation statements)

References 5 publications

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“…The MFR may be influenced by the molecular structure as well as by physical characteristics of polymer and which relate to the flow properties and processability of the polymeric materials .…”

Section: Resultsmentioning

confidence: 99%

Functionalized siloxane‐silsesquioxane resins and polypropylene‐based composites: Morphological, structural, thermal, and mechanical properties

et al. 2018

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Non‐functionalized and n‐alkyl‐functionalized siloxane‐silsesquioxane resins (S4SQ) were synthesized and characterized to confirm their structure and properties. Polypropylene (PP) composites with S4SQ resins as fillers were prepared by the melt blending. The influence of the kinds and amounts of fillers on the structural, morphological and thermal properties as well as mechanical characteristics and processability was determined. High compatibility of composites with functionalized resins resulted in more homogenous dispersion of filler particles in comparison with the composites which contained a non‐functionalized resin. Moreover, the introduction of S4SQ resins into PP strongly affected the crystalline structure of the polymer matrix and the free‐volume properties of composites. Siloxane‐silsesquioxane resins changed the contributions of the α‐ and β‐crystalline phases and they increased the crystal sizes of PP. The PP/S4SQ composites were also characterized by the improved crystallization temperature and crystallinity degree while the melting temperature and processability were changed only slightly. The mechanical properties of the PP/S4SQ materials were found to be dependent mostly on the degree of filler dispersion and crystalline structure of the composite materials. POLYM. COMPOS., 40:3101–3114, 2019. © 2018 Society of Plastics Engineers

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Section: Resultsmentioning

confidence: 99%

Functionalized siloxane‐silsesquioxane resins and polypropylene‐based composites: Morphological, structural, thermal, and mechanical properties

et al. 2018

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“…The graphs needed to calculate the activation energy (E a ) of the melting flow determined by the Eq. (4) were plotted using data from the device [22]. A linear relationship between MFI and temperature was obtained by matching the regression line, which slope coefficient corresponds to the value of E a /R, where R is the universal gas constant.…”

Section: Methodsmentioning

confidence: 99%

“…The peak at 1730 cm −1 assign to the free carbonyl group, while at 1699 cm −1 to the hydrogen bounded carbonyl group in crystalline phase of hard segment domains. Moreover, the hydrogen bounded C=O group stretching band associated with the amorphous phase is unnoticeable [11,22,26]. Normalized fragments of the FTIR spectrums in the range of the occurrence of the multiple band and the N-H groups absorption band are shown in Fig.…”

Section: Ftirmentioning

confidence: 99%

Investigation of Thermoplastic Polyurethanes Synthesized via Two Different Prepolymers

2019

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The man aim of this work was to investigate the effect of the molecular weight of polyols, mixture of prepolymers, and [NCO]/[OH] molar ratio used during the prepolymer chain extending step on the chemical structure, thermomechanical and mechanical properties, and thermal stability of thermoplastic poly(ether-urethane)s In this work thermoplastic poly(etherurethane)s were synthesized by using polyols with a various molecular weight, 4,4′-diphenylmethane diisocyanate and biobased glycol. Materials were obtained by a two-step method. The tests were carried out for polyurethanes obtained from a mixture of prepolymers and for reference samples. In the case of materials obtained with using mixture of prepolymers, the ratio of both prepolymers was determined on 50/50 weight percent. Soft segments of materials prepared with using mixture consist of two different polyols. The chemical structure was analyzed using FTIR spectroscopy. The Gaussian deconvolution technique was used to study the hydrogen bonding as well as to decompose carbonyl region of three peaks in various TPUs. The thermal degradation behavior was investigated by using thermogravimetric analysis at heating rates of 10 °C/ min. It was confirmed that the mixture of prepolymers has an effect of the degree of phase separation, thermal stability and selected properties of synthesized thermoplastic poly(ether-urethane)s.

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“…In this work, neat polymers and POSS-containing nanocomposites were subjected to the MFR tests which are widely used to characterize the polymer processability [82,83]. The MFR values for the studied polyethylene materials are presented in Fig.…”

Section: Processability-mfr Studiesmentioning

confidence: 99%

Study of polyethylene nanocomposites with polyhedral oligomeric silsesquioxane nanofillers—from structural characteristics to mechanical properties and processability

et al. 2017

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Evaluation of the influence of testing parameters on the melt flow index of thermoplastics

Cited by 23 publications

References 5 publications

Functionalized siloxane‐silsesquioxane resins and polypropylene‐based composites: Morphological, structural, thermal, and mechanical properties

Functionalized siloxane‐silsesquioxane resins and polypropylene‐based composites: Morphological, structural, thermal, and mechanical properties

Investigation of Thermoplastic Polyurethanes Synthesized via Two Different Prepolymers

Study of polyethylene nanocomposites with polyhedral oligomeric silsesquioxane nanofillers—from structural characteristics to mechanical properties and processability

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