Aging of polypropylene random copolymers studied by NMR relaxometry

Cali, Jonathan; Hu, Weiguo; Kysor, Everett; Kohlmann, Olaf

doi:10.1016/j.polymer.2021.124102

Cited by 5 publications

(3 citation statements)

References 21 publications

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“…Then, 30–40 mg of polymers was cut into small pieces and loaded into the NMR sample tubes. Only the first 240 μs of data were used for fitting a three-phase model (crystalline, interfacial, and amorphous phases), from which crystallinity was calculated …”

Section: Methodsmentioning

confidence: 99%

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Biodegradable High-Molecular-Weight Poly(pentylene adipate-co-terephthalate): Synthesis, Thermo-Mechanical Properties, Microstructures, and Biodegradation

Zheng,

Kim,

et al. 2023

ACS Sustainable Chem. Eng.

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Poly(pentylene adipate-co-terephthalate) (PPAT) is a promising biobased and biodegradable polymer that can replace polyethylene in flexible packaging films where biodegradability is desired. High-molecular-weight (100K–145 KDa) aliphatic–aromatic polyester PPAT was successfully synthesized, and the effects of reaction conditions on molecular weight were reported. PPAT polyesters were characterized for polymer compositions, number-average unit length, thermal transitions, and rheological properties. PPAT compression-molded films were characterized for crystallinity and tensile properties to correlate micro- and macroproperties. PPAT compression-molded films exhibited up to a 76% higher tensile modulus than compression-molded films from poly(butylene adipate-co-terephthalate) (PBAT), making PPAT films potentially comparable with compression-molded films from linear low-density polyethylene (LLDPE). PPAT is biodegradable in soil and freshwater environments with estimated 90% biodegradation times of 504–580 and 604–845 days, respectively, while PBAT takes 971 days in soil and 395 days in freshwater.

show abstract

Section: Methodsmentioning

confidence: 99%

“…Only the first 240 μs of data were used for fitting a three-phase model (crystalline, interfacial, and amorphous phases), from which crystallinity was calculated. 23 Mechanical properties were tested by a universal testing system (Instron). Uniform polymer films were prepared by a heat press machine at 180 °C.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Biodegradable High-Molecular-Weight Poly(pentylene adipate-co-terephthalate): Synthesis, Thermo-Mechanical Properties, Microstructures, and Biodegradation

Zheng,

Kim,

et al. 2023

ACS Sustainable Chem. Eng.

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“…It is reported that the crystallization capacity of polymers is significantly increased in the presence of nucleating agents and one of the most attractive and most mentioned frequently belongs to an α-nucleating agent [ 13 ]. Incorporation of α-nucleating agents into the PP matrix can provide a new solution to improve the crystallization and mechanical properties in the PP industry, where the presence of α-nucleating agents can promote the ability to form crystal nuclei, increase the rate of heterogeneous nucleation and crystallization, and reduce the spherulite size of PP [ 14 , 15 ]. Furthermore, the mechanical and optical properties of PP, including impact strength, tensile strength, flexural modulus and haze value, can be improved by reducing the size of spherulites [ 16 , 17 , 18 , 19 ].…”

Section: Introductionmentioning

confidence: 99%

Exploitation of a New Nucleating Agent by Molecular Structure Modification of Aryl Phosphate and Its Effect on Application Properties of the Polypropylene

Lin,

Zhang,

Zhao

et al. 2023

Polymers

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In this work, a novel α-nucleating agent (NA) for polypropylene (PP) termed APAl-3C-12Li was prepared and evaluated compared with the commercially available type NA-21. For the synthesis of the organophosphate-type NA (APAl-3C), the -OH group of the acid part of NA-21 was substituted by the isopropoxy group. The structure of APAl-3C was analyzed by spectroscopy and element analysis, the results of which were consistent with the theoretical molecular formula. APAl-3C’s thermal stability was studied by differential scanning calorimetry (DSC) and thermogravimetry (TG), which showed only weak mass loss below 230 °C, meaning that it would not decompose during the processing of PP. The APAl-3C-12Li was used as a novel nucleating agent, studying its effects on crystallization, microstructure, mechanical and optical properties. Tests were performed in a PP random copolymer at different contents, in comparison to the commercial NA-21. The composite with 0.5 wt% APAl-3C-12Li has a similar crystallization temperature of 118.8 °C as with the addition of 0.5 wt% NA-21. An advantage is that the composite with the APAl-3C-12Li has a lower haze value of 9.3% than the counterpart with NA-21. This is due to the weaker polarity of APAl-3C-12Li after the introduction of methyl and better uniform dispersion in the PP matrix, resulting in stronger improvement of optical and mechanical properties.

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Time-domain NMR in polyolefin research

Litvinov

Men

2022

Polymer

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Aging of polypropylene random copolymers studied by NMR relaxometry

Cited by 5 publications

References 21 publications

Biodegradable High-Molecular-Weight Poly(pentylene adipate-co-terephthalate): Synthesis, Thermo-Mechanical Properties, Microstructures, and Biodegradation

Biodegradable High-Molecular-Weight Poly(pentylene adipate-co-terephthalate): Synthesis, Thermo-Mechanical Properties, Microstructures, and Biodegradation

Exploitation of a New Nucleating Agent by Molecular Structure Modification of Aryl Phosphate and Its Effect on Application Properties of the Polypropylene

Time-domain NMR in polyolefin research

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