A method to reveal bulk and surface crystallinity of Polypropylene by FTIR spectroscopy - Suitable for fibers and nonwovens

Lanyi, Franz J.; Wenzke, Nicolai; Kaschta, Joachim; Schubert, Dirk W.

doi:10.1016/j.polymertesting.2018.08.018

Cited by 29 publications

(18 citation statements)

References 36 publications

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“…The emergence of a band around 1725 cm-1 was observed for all samples, the presence of this signal for the spectra indicates the presence of a carbonyl group (C = O) which is derived from the polyester group 27 . Its presence suggests that in the structure of the analyzed samples there is additionally a PET thermoplastic polymer.…”

Section: Resultsmentioning

confidence: 82%

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Covid-19 respiratory protection: the filtration efficiency assessment of decontaminated FFP2 masks responding to associated shortages

Benboubker

Oumokhtar

Hmami

et al. 2021

Preprint

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During the Covid-19 pandemic, healthcare workers were extremely vulnerable to infection with the virus and needed continuous protection. One of the most effective and widely used means of protection was the FFP2 respirator. Unfortunately, this crisis created a shortage of these masks, prompting hospitals to explore opportunities to reuse them after decontamination.An approach for assessing the filtration efficiency of decontaminated FFP2 masks has been proposed and applied to evaluate the possibilities of their safe reuse. The decontamination processes adopted are those based on moist heat or hydrogen peroxide. The approach introduces efficiency measures that define the filtration and protection capacity of the masks, which characterize both chemical and structural changes, and encompasses many techniques including scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The test protocol was applied to mask samples that had endured different decontamination cycles and the results of their efficiency measures were compared to brand-new masks’ performances.The main result was that chemical and structural characterization of the decontaminated masks have shown no substantial change or deformation of their filter media structures. Indeed, the respiratory resistance test has shown that the results of both the FFP2 masks that have undergone a hydrogen peroxide disinfection cycle or a steam autoclave cycle remained constant with a small variation of 10 Pa from the EN149 standard. The chemical characterization, on the other hand, has shown that the filter media of the decontaminated masks remains unchanged, with no detectable chemical derivatives in its constituents.

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Section: Resultsmentioning

confidence: 82%

“…All the dominant bands observed are the characteristic vibration bands of isotactic (iPP) 26 27 . The FTIR spectrum of our samples shows a strong alkane C-H stretching vibration band from 2841 to 2955 cm -1 , and the peak at 1380 and 1454 cm -1 is represented by the C-H bending.…”

Section: Resultsmentioning

confidence: 96%

Covid-19 respiratory protection: the filtration efficiency assessment of decontaminated FFP2 masks responding to associated shortages

Benboubker

Oumokhtar

Hmami

et al. 2021

Preprint

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“…Surface crystallinity measurement ( X cs ) was performed by FTIR with using diamond (C) and germanium (Ge) crystal. Surface crystallinity was determined from the ratio of maximum peak height at 998 cm −1 and the maximum peak height at 974 cm −1 since absorption band at 998 cm −1 corresponds to the crystalline phase and absorption band at 974 cm −1 is independent on the crystalline phase content …”

Section: Methodsmentioning

confidence: 99%

Solid‐state grafting of maleic anhydride onto polypropylene: The influence of morphology of polypropylene on heterogeneous reaction

Kučera

Petruš

Bálková

et al. 2020

Polymer Engineering & Sci

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Polypropylene (PP) was modified with maleic anhydride (MAH) via heterogeneous solid-state radical grafting performed in a fluidized polymerization reactor. The effect of PP morphology and different concentration of initiator (dibenzoyl peroxide, DBP) on the course of the reaction and grafting efficiency was evaluated with using infrared spectroscopy, scanning electron microscopy (SEM) and particle surface analysis (BET method). With respect to obtained results, the reaction course can be strongly affected by the reaction conditions and PP morphology. Unlike the reactive modification in melt, heterogeneous reaction exhibits lower extent of β-scission albeit the reaction conversion is lower. Solid-state grafting can be used as an alternative method for the surface modification of nonpolar surfaces with polar monomers under mild conditions. K E Y W O R D S maleic anhydride,

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“…A previous publication had already demonstrated the proportionality of the peak ratio h 998 / h 973 and the degree of crystallinity ( X c ) in polypropylene . The peak height of both peaks was determined by initially drawing a linear baseline determined by the points at 1025 and 950 cm −1 .…”

Section: Methodsmentioning

confidence: 99%

“…A previous publication had already demonstrated the proportionality of the peak ratio h 998 /h 973 and the degree of crystallinity (X c ) in polypropylene. [35] The peak height of both peaks was determined by initially drawing a linear baseline determined by the points at 1025 and 950 cm À1 . In a second step, the height between the baseline and the highest measured signal value in the range 960-985 cm À1 (for the band at 973 cm À1 ) and in the range 985-1005 cm À1 (for the band at 998 cm À1 ) was determined.…”

Section: Fourier-transform Infrared Spectroscopymentioning

confidence: 99%

On the Determination of the Enthalpy of Fusion of α‐Crystalline Isotactic Polypropylene Using Differential Scanning Calorimetry, X‐Ray Diffraction, and Fourier‐Transform Infrared Spectroscopy: An Old Story Revisited

Lanyi¹,

Wenzke²,

Kaschta³

et al. 2019

Adv Eng Mater

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The crystallinity determination of polymers using differential scanning calorimetry (DSC) is a standard procedure in industrial and university research. Its value strongly depends on the enthalpy of fusion, which cannot be determined directly using DSC, but must be calibrated using external methods such as X‐ray diffraction (XRD) or density measurements. In addition, the determination of the enthalpy or heat of fusion is not trivial and thus error‐prone; hence, values from 60 to 260 J g−1 are quoted for polypropylene in the literature. It is therefore of great relevance to devise a consistent method to determine the heat of fusion. To determine the heat of fusion for polypropylene, a sample set with a broad range of crystallinities is produced using cooling rates between 1 and ≈3500 K min−1. The melting enthalpy of the samples is determined using DSC measurements. The determination of the melting enthalpy based on XRD measurements is discussed in detail, validated using Fourier‐transform infrared spectroscopy (FTIR), and compared with values quoted in the open literature. Although two different approaches are used to determine the enthalpy of fusion, a value of 170 ± 3 J g−1 is determined.

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A method to reveal bulk and surface crystallinity of Polypropylene by FTIR spectroscopy - Suitable for fibers and nonwovens

Cited by 29 publications

References 36 publications

Covid-19 respiratory protection: the filtration efficiency assessment of decontaminated FFP2 masks responding to associated shortages

Covid-19 respiratory protection: the filtration efficiency assessment of decontaminated FFP2 masks responding to associated shortages

Solid‐state grafting of maleic anhydride onto polypropylene: The influence of morphology of polypropylene on heterogeneous reaction

On the Determination of the Enthalpy of Fusion of α‐Crystalline Isotactic Polypropylene Using Differential Scanning Calorimetry, X‐Ray Diffraction, and Fourier‐Transform Infrared Spectroscopy: An Old Story Revisited

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