A Modified Waxs Method for the Crystallinity of Polymers Determination

Rabiej, Małgorzata; Rabiej, Stanisław; Włochowicz, A.

doi:10.1142/9789812702913_0077

Cited by 19 publications

(27 citation statements)

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“…WAXS curves, corrected for background scattering and normalized to the same integrated intensity in the whole registration range, were decomposed into parts arising from crystalline and amorphous phases, using the WAXFIT computer software . The decomposition was performed by means of the approximation method using the Particle Swarm Optimization procedure .…”

Section: Methodsmentioning

confidence: 99%

Study and evaluation of dispersion of polyhedral oligomeric silsesquioxane and silica filler in polypropylene composites

et al. 2018

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Various methods were used for evaluation of homogeneity of polypropylene (PP) matrix composites with octakis([n‐octyl]dimethylsiloxy)octasilsesquioxane, octakis([n‐octadecyl]dimethylsiloxy)octasilsesquioxane, and silica (SiO2) fillers. The filler dispersion was determined on the basis of the results from the wide‐angle X‐ray scattering (WAXS) analysis, from the tests of selected mechanical properties, from scanning electron microscopy (SEM) with energy dispersive X‐ray spectroscopy and from the decomposable entropic descriptor method. The use of different methods allowed to evaluate homogeneity of PP composites on various levels and with different precisions. The dispersion degree was found to be mostly depended on the kind and amount of the filler used. The presence of long n‐alkyl chain substituents in POSS molecules greatly improved the level of filler dispersion in the polymer matrix in comparison to silica which was visually assessed by SEM. The WAXS method revealed the formation of filler aggregates in the PP matrix which influenced the structural characteristic of PP composites and changed the mechanical properties of those materials. However, the decomposable entropic descriptor method provided the possibility of quantitative and the most objective estimation of homogeneity of the obtained composite materials. POLYM. COMPOS., 40:1354–1364, 2019. © 2018 Society of Plastics Engineers

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Section: Methodsmentioning

confidence: 99%

Study and evaluation of dispersion of polyhedral oligomeric silsesquioxane and silica filler in polypropylene composites

et al. 2018

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“…The WAXS curves—corrected for background scattering and normalized to the same integrated intensity I in the whole registration range—were decomposed into parts arising from crystalline and amorphous phases, using the WAXSFIT computer software . The decomposition was performed by means of the approximation method which consists in constructing a theoretical curve which is best fitted to the experimental one, using a suitable optimization procedure . The crystallinity degree was calculated as the ratio of the integral intensity contained in all crystalline peaks to the total integral intensity scattered by the sample in the whole range recorded.…”

Section: Methodsmentioning

confidence: 99%

Ethylene/POSS copolymerization behavior of postmetallocene catalysts and copolymer characteristics

Groch

Dziubek

Czaja

et al. 2017

J. Polym. Sci. Part A: Polym. Chem.

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Copolymerization of ethylene with iso‐butyl substituted monoalkenyl(siloxy)‐ or monoalkenylsilsesquioxane (POSS) comonomers over bis(phenoxy‐imine) and salen‐type titanium and zirconium catalysts was studied. It was found that the polyreaction performance was significantly depended by the kind of the catalyst and by the structure and concentration of POSS in the feed. The POSS comonomer was efficiently incorporated into the polymer chain at up to 0.2 mol %. The differences in the copolymer compositions as the functions of the catalyst kind and the POSS comonomer were observed, including the varied number‐average sequence length of ethylene and unsaturated end groups, as determined by 1H NMR and FT‐IR. The presence of POSS comonomers affected also the melting and crystallization behavior of the copolymers, as evidenced by DSC, because of influence on the polymer chain arrangement. The POSS units could act as the nucleating agents. Moreover, the crystal and structural parameters of ethylene/POSS copolymers were evaluated on the basis of X‐ray results, and the limited self‐aggregation of POSS incorporated into the polymer chain, the small number and size of POSS aggregates, and the increased crystallinity degree of copolymers were demonstrated. The ethylene/POSS copolymers produced by postmetallocenes offered also high thermal stability and interesting morphological properties. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3918–3934

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“…2b. This has been done using the WAXSFIT program [42]. The amounts K α , Κ β , and Κ γ of the α, β, and γ phases in the total crystalline component of PP specimens were determined using the equations given by Turner-Jones et al [43] for the two-phase case (α + β and α + γ) and by Obadal et al [44] for the three-phase one.

Fig.…”

Section: Methodsmentioning

confidence: 99%

The role of nucleating agents in high-pressure-induced gamma crystallization in isotactic polypropylene

et al. 2014

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Nucleation of the γ-form in isotactic polypropylene (PP) under high pressure was investigated. Three nucleating agents were used to nucleate crystallization of PP under atmospheric pressure: commercial Hyperform HPN-20E from Milliken Chemical, poly(tetrafluoroethylene) particles nucleating the α-form, and calcium pimelate nucleating the β-form. Crystallization of neat PP and PP with addition of 0.2 wt% of the nucleating agents was studied. Specimens were either kept at 200 °C under pressure of 200 MPa for time ranging from 2 min to 4 h or for 15 min under pressure ranging from 1.3 to 300 MPa. After cooling to ambient temperature and releasing the pressure, the specimens were analyzed by DSC, WAXD, and PLM to have an insight into the structure and to determine a crystallinity level and contents of crystallographic forms. Both α-nucleating agents strongly nucleated crystallization of PP under high pressure in the γ-form, whereas the β-nucleating agent had only a slight effect. The results show the possibility to use nucleating agents to nucleate the γ-form of PP under high pressure.

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A Modified Waxs Method for the Crystallinity of Polymers Determination

Cited by 19 publications

References 0 publications

Study and evaluation of dispersion of polyhedral oligomeric silsesquioxane and silica filler in polypropylene composites

Study and evaluation of dispersion of polyhedral oligomeric silsesquioxane and silica filler in polypropylene composites

Ethylene/POSS copolymerization behavior of postmetallocene catalysts and copolymer characteristics

The role of nucleating agents in high-pressure-induced gamma crystallization in isotactic polypropylene

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