Brittle ductile transition of POE toughened HDPE and its lowest rigidity loss: effect of HDPE molecular weight

Core-shell structured particles have been used to toughen brittle polylactide (PLA) extensively. In this research, reactive core-shell (RCS) particles with polybutadiene (PB) as core and the terpolymer styrene-acrylonitrile-glycidyl methacrylate as shell were prepared to improve the toughening ability of RCS for PLA. The tert-dodecyl mercaptan (TDDM) content was varied during polymerization and higher TDDM concentrations induced lower grafting and cross-linking of the PB phase, which significantly influenced the dispersed phase morphology and toughness of RCS toughened PLA blends. With the increase of TDDM content, the phase morphology of RCS changed from uniform dispersion, net-like structure to an agglomeration pattern. The impact strength of PLA blends increased with TDDM content and reached 922 J/m for the PLA/RCS-T5 (TDDM: 1.18 wt%), which was 30 times higher than pristine PLA and $3 times than PLA/RCS-T0 blend. Higher TDDM contents decreased toughening efficiency. Appropriate TDDM contents decreased the glass transition temperature (T g ) and cross-linking degree of RCS particles which enhanced the cavitation ability of the PB core phase and promoted the shear yielding of PLA matrix. The modification effect of TDDM solves the problem of insufficient toughening ability of core-shell particles. Under the same toughener content, the modified RCS particles make the PLA blend achieve super toughness.

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“…On the other hand, the PLA//RCS‐T5 blend displays higher toughness and stiffness than the toughened HDPE blend. [ 40 ]…”

Section: Resultsmentioning

confidence: 99%

Modification of reactive PB‐g‐SAG core–shell particles to achieve higher toughening ability for brittle polylactide

Hao

Zheng

Sun

2022

Polymer Engineering & Sci

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“…2,3 However, an intractable problem is that toughness increasing is generally at the cost of the loss of rigidity. 4,5 Our previous theoretical studies show that 26.1% modulus loss is the lowest value for such rubber-toughened PP composites, 6 whereas it can decrease from 26.1% for one phase modifier to 13.5% for the core−shell modifier with a PE core and to 5.4% for the core−shell modifier with a PP core. 1 These results are supported by some experimental studies.…”

Section: ■ Introductionmentioning

confidence: 96%

“…Toughness and rigidity are two parameters that determine whether a polymer can be used as an engineering material. , However, an intractable problem is that toughness increasing is generally at the cost of the loss of rigidity. , Our previous theoretical studies show that 26.1% modulus loss is the lowest value for such rubber-toughened PP composites, whereas it can decrease from 26.1% for one phase modifier to 13.5% for the core–shell modifier with a PE core and to 5.4% for the core–shell modifier with a PP core . These results are supported by some experimental studies. , Polymer scientists and engineers aim to obtain high-impact polymer composites with increased core modulus with no loss of rigidity or even higher rigidity than that of the matrix polymer.…”

Section: Introductionmentioning

confidence: 99%

A Strategy to Develop Homo-polypropylene Composites with High Impact and High Rigidity

Wang,

Gao,

Jin

et al. 2024

Macromolecules

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One of the significant drawbacks of polymer toughening is the trade-off between improved toughness and reduced rigidity. Based on our previous research (Li et al. Polymer, 2020, 191, 122237), to produce rubber particle-toed polymer composites with high impact and low rigidity loss, it is best to have a high modulus for the core and a low modulus for the shell. The question is whether we can construct high-impact polymer composites while maintaining or increasing their rigidity by increasing the core modulus. Here, SiO2/POE core–shell particles are used to toughen the polymer composites. According to theoretical analysis, the modulus of the composites can be much higher than that of the polymer matrix. Additionally, the rigidity of the PP composites is greatly influenced by the composition of the core (SiO2) and shell (POE) materials, as well as the amount of SiO2/POE core–shell particles. Experimentally, a PP composite with a high impact and high rigidity is successfully fabricated. The notched impact strength is 44.6 kJ/m2, and the flexural modulus is 1644 MPa, consistent with the theoretical calculations. To the best of our knowledge, this is the highest-performing PP composite with excellent impact strength and rigidity.

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“…Polymer blending represents an efficient and cost-effective strategy for enhancing polymer properties. , A substantial body of the literature showcases studies that have implemented thermoplastic elastomers to enhance the toughness of HDPE. ,− However, in many of these attempts, the enhancement has come at the cost of reduced stiffness due to the high concentration of the secondary phase. Recently, a novel generation of polymer composites known as in situ micro/nanofibrillar composites has garnered significant attention for their ability to enhance the mechanical, − rheological, − foaming, − and crystallization − behaviors of polymers.…”

Section: Introductionmentioning

confidence: 99%

Enhancing Mechanical Performance of High-Density Polyethylene at Different Environmental Conditions with Outstanding Foamability through In-Situ Rubber Nanofibrillation: Exploring the Impact of Interface Modification

Kheradmandkeysomi,

Salehi,

Jalali

et al. 2024

ACS Appl. Mater. Interfaces

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In this study, we utilized in situ nanofibrillation of thermoplastic polyester ether elastomer (TPEE) within a high-density polyethylene (HDPE) matrix to enhance the rheological properties, foamability, and mechanical characteristics of the HDPE nanocomposite at both room and subzero temperatures. Due to the inherent polarity differences between these two components, TPEE is thermodynamically incompatible with the nonpolar HDPE. To address this compatibility issue, we employed a compatibilizer, styrene/ethylene-butylene/styrene copolymer-grafted maleic anhydride (SEBS-g-MA), to reduce the interfacial tension between the two blend components. In the initial step, we prepared a 10% masterbatch of HDPE/TPEE with and without the compatibilizer using a twin-screw extruder. Subsequently, we processed the 10% masterbatch further through spun bonding to create fiber-in-fiber composites. Scanning electron microscopy (SEM) analysis revealed a significant reduction in the spherical size of HDPE/TPEE particles following the inclusion of SEBS-g-MA, as well as a much smaller TPEE nanofiber size (approximately 60–70 nm for 5% TPEE). Moreover, extensional rheological testing revealed a notable enhancement in extensional rheological properties, with strain-hardening behavior being more pronounced in the compatibilized nanofibrillar composites compared to the noncompatibilized ones. SEM images of the foam structures depicted substantial improvement in the foamability of HDPE in terms of the cell size and density following the nanofibrillation process and the use of the compatibilizer. Ultimately, the in situ rubber fibrillation and enhancement of HDPE and TPEE interface using a compatibilizer led to increasing the HDPE ductility at room and subzero temperatures while maintaining its stiffness.

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Brittle ductile transition of POE toughened HDPE and its lowest rigidity loss: effect of HDPE molecular weight

Cited by 12 publications

References 54 publications

Modification of reactive PB‐g‐SAG core–shell particles to achieve higher toughening ability for brittle polylactide

Modification of reactive PB‐g‐SAG core–shell particles to achieve higher toughening ability for brittle polylactide

A Strategy to Develop Homo-polypropylene Composites with High Impact and High Rigidity

Enhancing Mechanical Performance of High-Density Polyethylene at Different Environmental Conditions with Outstanding Foamability through In-Situ Rubber Nanofibrillation: Exploring the Impact of Interface Modification

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