Primitive structure and its morphology for describing highly branched structure of low-density polyethylene

Rungswang, Wonchalerm; Narkchamnan, Kanyanut; Petcharat, Nuchanat; Thitisak, Boonyakeat; Pathaweeisariyakul, Thipphaya

doi:10.1007/s00289-016-1893-y

Cited by 2 publications

(8 citation statements)

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“…Polyethylene (PE) is a plastic insulating material for electrical conductivity, malleable and hydrophobic [ 1 ]. Have been estimated that from 1950 to 2015, about 8.3 billion metric tons of plastic products, including PE, were produced, of which 6.3 billion metric tons became solid waste, of which 12% incinerated, while the remaining 79% was disposed of in landfills or inappropriately ended up in water bodies and natural ecosystems [ 2 ].…”

Section: Introductionmentioning

confidence: 99%

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Evaluation of two microcosm systems for co-treatment of LDPE _oxo and lignocellulosic biomass for biochar production

et al. 2021

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Background The co-transformation of solid waste of natural and anthropogenic origin can be carried out through solid-state-fermentation systems to obtain bio-products with higher added value and lower environmental impact. Methods To evaluate the effect of Pleurotus ostreatus on co-transformation of oxo-degradable low-density polyethylene (LDPEoxo) sheets and lignocellulosic biomass (LCB), were assembled two 0.75 L microcosm systems in vertical (VMS) and horizontal (HMS) position. The pre-treated sheets with luminescent O2 plasma discharges were mixed with pine bark, hydrolyzed brewer’s yeast and paper napkin fragments and incubated for 135 days at 20 ± 1.0 °C in the presence of the fungus. With the co-transformation residues, biochar (BC) was produced at 300 ± 1.0 °C (BC300) for 1 h, then used to carry out adsorption studies, using the malachite green dye (MG) at pH 4.0, 7.0 and 9.0 ± 0.2. Finally, the biochar was the substrate for the germination of carnation seeds (Dianthus caryophyllus) and Ray-grass (Lolium sp.) in vitro. Results For HMS, the decrease in static contact angle (SCA) was 63.63% (p = 0.00824) and for VMS 74.45% (p = 0.00219), concerning the pristine. Plastic roughness in VMS was higher (26%) concerning the control. Throughout the 135 days, there were fungal growth and consequently laccase (Lac), manganese peroxidase (MnP) and lignin peroxidase (LiP) activities. During the first 75 days, CO2 production increased to 4.78 ± 0.01 and 4.98 ± 0.01 mg g-1 for HMS and VMS, respectively. In MG adsorption studies, the highest amount of the colourant adsorbed at both pH 4.0 and 7.0 ± 0.2. Conclusions Finally, the biochar or the biochar enriched with low concentrations of plant growth-promoting microorganisms and inorganic fertilizer favours the germination of Dianthus caryophyllus and Lolium sp., seeds.

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Section: Introductionmentioning

confidence: 99%

“…According to PE density, it can be classified as high-, low- and linear low-density. Low-density polyethylene (LDPE) is composed of short chains of amorphous aliphatic carbon, joined by C-C bonds [ 1 , 3 ]. LDPE is crucial in the manufacture of single-use products, such as bags, cigarettes, packaging, cutlery, etc.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of two microcosm systems for co-treatment of LDPE _oxo and lignocellulosic biomass for biochar production

et al. 2021

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“…Typically LDPE has about 10–20 short chain branches (SCB)/1000 carbons, the level of which impacts the crystallinity of the material. A key feature of LDPE is long chain branching (LCB) which has a significant impact on physical and rheological properties, including melt strength. − LCB in LDPE has been characterized via a variety of techniques, including 13 C NMR spectroscopy, triple-detector gel permeation chromatography (TD-GPC), and rheology . For substantially linear ethylene polymer (SLEP), TD-GPC is a reliable approach to measure LCB, but for LDPE certain corrections to TD-GPC measurements are needed.…”

Section: Introductionmentioning

confidence: 99%

“…Rheological properties such as rheological ratio, shear thinning, and melt strength can provide some information about LCB content, but such measurements do not enable direct quantification of LCB. 13 C NMR spectroscopy, when performed correctly, provides an intrinsically quantitative method for LCB quantification, and it has been widely used to measure LCB level in SLEP. − 13 C NMR spectroscopy has also been used extensively to measure LCB content in LDPE by quantifying the resonance from the CH 2 group located at the third carbon from the chain end (CE 3 ) resonating at approximately δ 32.1–32.3 ppm (see Scheme ; the drawing is based on previous NMR reports , ). Prior papers report values for LCB content in LDPE where any contribution from C 6 branches to longer branches is included in the LCB value because it was not possible to resolve the C 6 resonance from the resonances corresponding to longer chains. ,,,− In addition, it has been reported previously that C 6 branches are not present in LDPE .…”

Section: Introductionmentioning

confidence: 99%

“…Low density polyethylene (LDPE), commercially produced since 1939, is produced via free radical polymerization at high temperature and high pressure autoclave, autoclave/tube, or tubular reactors. 1 A majority of manufacturers use tubular reactors now because they can produce material with both narrow and broad molecular weight distributions. Recent global consumption of polyethylene was 187 billion pounds with 23% being LDPE.…”

Section: ■ Introductionmentioning

confidence: 99%

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Long Chain Branching Detection and Quantification in LDPE with Special Solvents, Polarization Transfer Techniques, and Inverse Gated ¹³C NMR Spectroscopy

et al. 2018

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Recent global demand of polyethylene was 187 billion pounds with 23% being low density polyethylene (LDPE). LDPE is used in a variety of applications including liners, consumer bags, heavy duty sacks, caps, closures, toys, lamination, and agricultural films. A key feature of LDPE is the presence of long chain branching (LCB) which has a significant impact on physical and rheological properties, including melt strength. Previously it was reported that there are no C6 branches in LDPE, and therefore the common practice has been to use the resonance around 32.2 ppm as a measure of LCB content. Herein, the existence of C6 branches in LDPE is reported for the first time, enabled by the use of 1-chloronaphthalene as the NMR solvent. It is shown that the C6 branches have a contribution to the resonance around 32.2 ppm. This finding suggests that C6 branches should be measured in LDPE samples and be excluded from LCB quantification because they do not affect LDPE rheological properties as LCB does. The data obtained strongly suggest that C7 branches are present in much lower concentrations in the LDPE samples studied. The quantification of these resonances traditionally requires long acquisition time, even with the use of a cryoprobe. In this work, different polarization transfer techniques, refocused insensitive nuclei enhanced by polarization transfer (RINEPT), and distortionless enhancement by polarization transfer (DEPT) were compared in terms of their ability to enhance CH2 sensitivity, thus leading to a greater ability to observe the CH2 resonances belonging to the C6 branches. It was found that RINEPT with hard 180° 13C pulses is most suitable for this purpose. A much faster method is proposed for measuring LCB in LDPE that employs a combination of a conventional quantitative 13C NMR technique and a polarization transfer technique.

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Primitive structure and its morphology for describing highly branched structure of low-density polyethylene

Cited by 2 publications

References 25 publications

Evaluation of two microcosm systems for co-treatment of LDPE _oxo and lignocellulosic biomass for biochar production

Evaluation of two microcosm systems for co-treatment of LDPE _oxo and lignocellulosic biomass for biochar production

Long Chain Branching Detection and Quantification in LDPE with Special Solvents, Polarization Transfer Techniques, and Inverse Gated ¹³C NMR Spectroscopy

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Primitive structure and its morphology for describing highly branched structure of low-density polyethylene

Cited by 2 publications

References 25 publications

Evaluation of two microcosm systems for co-treatment of LDPE oxo and lignocellulosic biomass for biochar production

Evaluation of two microcosm systems for co-treatment of LDPE oxo and lignocellulosic biomass for biochar production

Long Chain Branching Detection and Quantification in LDPE with Special Solvents, Polarization Transfer Techniques, and Inverse Gated 13C NMR Spectroscopy

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Evaluation of two microcosm systems for co-treatment of LDPE _oxo and lignocellulosic biomass for biochar production

Evaluation of two microcosm systems for co-treatment of LDPE _oxo and lignocellulosic biomass for biochar production

Long Chain Branching Detection and Quantification in LDPE with Special Solvents, Polarization Transfer Techniques, and Inverse Gated ¹³C NMR Spectroscopy