Rheological/thermal properties of poly(ethylene terephthalate) modified by chain extenders of pyromellitic dianhydride and pentaerythritol

Dolatshah, Saeed; Ahmadi, Shervin; Ershad‐Langroudi, Amir; Jashni, Hedieh

doi:10.1002/app.49917

Cited by 13 publications

(21 citation statements)

References 70 publications

(176 reference statements)

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“…The effect of pyromellitic dianhydride (PMDA), as the most commonly used chain extender, on the properties of PET has been comprehensively investigated. 32 − 34 Incorporation of PMDA significantly decreases the carboxyl content, increases the intrinsic melt viscosity, and improves its rheological behavior. These properties are associated with increased molecular weight (MW) and chain entanglement.…”

Section: Introductionmentioning

confidence: 99%

“…Different types of chain extenders by adding reactive functional groups, including trimethyl trimellitate, isocyanates, epoxy-based compounds, bis-oxazolines, and organic phosphites are effective at increasing intrinsic viscosity, molecular mass, and melt strength. The effect of pyromellitic dianhydride (PMDA), as the most commonly used chain extender, on the properties of PET has been comprehensively investigated. − Incorporation of PMDA significantly decreases the carboxyl content, increases the intrinsic melt viscosity, and improves its rheological behavior. These properties are associated with increased molecular weight (MW) and chain entanglement.…”

Section: Introductionmentioning

confidence: 99%

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Reactive Blending of Recycled Poly(ethylene terephthalate)/Recycled Polypropylene: Kinetics Modeling of Non-Isothermal Crystallization

et al. 2023

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Plastics were developed to change our world for the better. However, plastic pollution has become a serious global environmental crisis. Thermoplastic polyesters and polyolefins are among the most abundant plastic waste. This work presents an in-depth non-isothermal crystallization kinetics analysis of recycled post-consumer poly(ethylene terephthalate) (rPET) and recycled polypropylene (rPP) blends prepared through reactive compounding. The effect of pyromellitic dianhydride (PMDA) on crystallization kinetics and phase morphology of rPET/rPP blends was investigated by differential scanning calorimetry (DSC) and microscopy techniques. DSC results showed that increasing rPP content accelerated rPET crystallization while reducing crystallinity, which indicates the nucleation effect of the rPP phase in blends. Further, it was found that the incorporation of PMDA increased the degree of crystallinity during non-isothermal crystallization, even though the rate of crystallinity decreased slightly due to its restriction effects. The non-isothermal crystallization kinetics was analyzed based on the theoretical models developed by Jeziorny, Ozawa, Mo, and Tobin. The activation energy of the crystallization process derived from Kissinger, Takhor, and Augis−Bennett models was found to increase in rPET/rPP blends with increasing PMDA due to hindered dynamics of the system. Rheological measurements revealed that rPET melt viscosity is remarkably increased in the presence of PMDA and reactive blending with rPP relevant for processing. Moreover, nanomechanical mapping of the rPP phase dispersed in the rPET matrix demonstrated the broadening of the interfacial domains after reactive blending due to the branching effect of PMDA. Findings from this study are essential for the recycling/ upcycling thermoplastics through non-isothermal fabrication processes, such as extrusion and injection molding, to mitigate the lack of sorting options.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Reactive Blending of Recycled Poly(ethylene terephthalate)/Recycled Polypropylene: Kinetics Modeling of Non-Isothermal Crystallization

et al. 2023

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“…Dolatshah et al demonstrated that DBTDL may operate as an accelerator of the interaction between PET and PMDA, as well as PENTA, enhancing the chain extension rate and improving rheological characteristics in lower time. [ 55 ] Hanley et al obtained similar results for branching and chain extension of PET chains employing PMDA and PENTA as chain extenders. They showed that with raising the content of chain extender, weight average molecular weight (Mw), molecular weight range, and apparent viscosity increased considerably, while number average molecular weight (Mn) was almost constant and MFI got decreased.…”

Section: Introductionmentioning

confidence: 77%

“…Reaction of polyethylene terephthalate (PET) and: (A) pyromellitic dianhydride (PMDA), (B) pentaerythriol (PENTA), (C) PMDA, and PENTA [ 55 ] …”

Section: Resultsmentioning

confidence: 99%

“…The interaction between the carboxyl groups of carbon nanotube (CNT) and the carbonyl groups of polyethylene terephthalate (PET) [2] For the PM1.5/PE0.5 sample, the quantity of storage modulus was higher than that of the PET sample, which indicates an increase in stress relaxation time to more elasticity due to increasing chain length and increasing the number of long branches and entanglement. [26,40,53,61] Generally, increasing the chain length, F I G U R E 3 Reaction of polyethylene terephthalate (PET) and: (A) pyromellitic dianhydride (PMDA), (B) pentaerythriol (PENTA), (C) PMDA, and PENTA [55] F I G U R E 4 The storage modulus plots versus frequency at 280 C the number of long branches and entanglement make the chains more capable of transferring external force, which leads to the storage modulus increment. [62] Also, the variations in the storage modulus/frequency for this sample were lower than the PET sample and the amount of storage modulus has lower frequency dependency.…”

Section: Storage Modulusmentioning

confidence: 99%

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Long‐chain branching of polyethylene terephthalate: Rheological/thermal properties of polyethylene terephthalate/carbon nanotube nanocomposite

Dolatshah

Ahmadi

Ershad‐Langroudi

et al. 2022

Polymer Engineering & Sci

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Thermal degradation of polyethylene terephthalate (PET)/carbon nanotube (CNT) nanocomposites is a serious issue in the manufacturing process of this nanocomposite that can limit the applications of the nanocomposite. In this study, the effects of two kinds of chain extenders, pyromellitic dianhydride (PMDA) and pentaerythritol (PENTA), on the rheological behavior, thermal characteristics, and crystallinity of the PET were investigated. The results of shear rheology revealed improvement of the storage modulus and complex viscosity, which indicated the recoupling of broken chains, increasing the chain length, and the generation of long branches was the reason for chain extension. Also, differential scanning calorimetry (DSC) results clarified an increase in PET crystallization rate in the presence of CNT and chain extenders. Furthermore, SEM was performed to detect CNT dispersion in the nanocomposite, and four-probe technique test was utilized to determine the influence of CNT on the electrical properties of PET.

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Evaluation of PET recyclability and characterization of modified reprocessed‐PET for industrial application

Kim,

Park,

Choo

et al. 2024

J of Applied Polymer Sci

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Polyethylene terephthalate (PET) is used in a variety of packaging applications, such as bottles, films, fibers, for its cost‐effective and excellent physical properties. However, the increase in plastic usage and packaging waste has become major global problems. Therefore, the importance of plastic recycling is being emphasized. In this study, the bottle‐grade PET was repeatedly melt processed up to three times to evaluate of PET recyclability. Intrinsic viscosity (IV) and mechanical properties have significantly decreased due to chain scission during the melt reprocessing. In particular, the IV of 3rP (reprocessing three times) decreased to 0.582 dL/g, and the mechanical properties decreased more than twice compared with 0rP. To enhance the physical properties of reprocessed PET (rP‐PET), it was modified using two chain extenders. The IV of the modified 3rP‐PET increased from 0.645 to 0.737 dL/g. And the tensile strength was improved up to approximately 93% of the 0rP properties, confirming the chain extension effect. Additionally, a biaxial orientation process was applied to confirm the feasibility of modified rP‐PET to various industrial packaging applications. Consequently, as the stretching ratio increased, the physical properties of modified rP‐PET improved, confirming the feasibility of rP‐PET in various packaging fields.

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Rheological/thermal properties of poly(ethylene terephthalate) modified by chain extenders of pyromellitic dianhydride and pentaerythritol

Cited by 13 publications

References 70 publications

Reactive Blending of Recycled Poly(ethylene terephthalate)/Recycled Polypropylene: Kinetics Modeling of Non-Isothermal Crystallization

Reactive Blending of Recycled Poly(ethylene terephthalate)/Recycled Polypropylene: Kinetics Modeling of Non-Isothermal Crystallization

Long‐chain branching of polyethylene terephthalate: Rheological/thermal properties of polyethylene terephthalate/carbon nanotube nanocomposite

Evaluation of PET recyclability and characterization of modified reprocessed‐PET for industrial application

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