Mechanical performance of poly(propylene carbonate)-based blends and composites

Kousaalya, Adhimoolam Bakthavachalam; Biddappa, Bopaiah Ittira; Rai, S.K.; Pilla, Srikanth

doi:10.1016/b978-1-78242-373-7.00016-0

Cited by 7 publications

(6 citation statements)

References 93 publications

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“…Both the storage modulus ( G ′) and loss modulus ( G ″) increase with increasing frequency in the tested region (Figure ). The G ″ is related to the viscous behavior of a polymer, G ′ expresses the elastic response of a polymer, and tan(δ) is the ratio of the two (viscous or energy dissipation over elastic or storage behavior). , For both evaluated samples, G ″ has higher values than G ′ over the entire tested frequency region, and no crossover frequency is detected. The former indicates that the viscous portion of the viscoelastic performance of the HEUR aqueous solutions is predominant .…”

Section: Resultsmentioning

confidence: 95%

Insight Into Solventless Production of Hydrophobically Modified Ethoxylated Urethanes (HEURs): The Role of Moisture Concentration, Reaction Temperature, and Mixing Efficiency

et al. 2022

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In this work, we report for the first time on the influence of the quality of reactants and reaction conditions on the production of hydrophobically modified ethoxylated urethanes (HEURs) and selected prepolymers without the use of solvents. We show that the polyol water concentration is detrimental to the progress of the main urethane forming reaction, confirming the necessity of carefully drying the reactants below 1000 ppm to suppress the consumption of diisocyanate toward urea during HEUR synthesis. Increasing the mixing speed (≈30 to 750 rpm), reaction temperature (80−110 °C), and catalyst concentration (0.035−2.1 wt % bismuth carboxylate) can significantly increase the rate of molecular weight buildup, but their effect decreases with time as the bulk viscosity increases and mixing limitations eventually take over, leading to the Weissenberg effect and chain growth termination. Consequently, for the selected formulation, the maximum product molecular weight attained lies in the range of ≈20 000−22 000 g/ mol, irrespective of the specific process conditions applied.

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Section: Resultsmentioning

confidence: 95%

Insight Into Solventless Production of Hydrophobically Modified Ethoxylated Urethanes (HEURs): The Role of Moisture Concentration, Reaction Temperature, and Mixing Efficiency

et al. 2022

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“…This part is called as loss modulus, and is highly important to evaluate the viscous response and damping characteristics. On the other hand, the remaining part of the load acting on the polymer structures is stored elastically, and is called as the storage modulus 43 . In the current study, storage and loss moduli were calculated to determine the effect of LVI‐induced local damages and thermoplastic veil interleaves on the performance characteristics of the CFRP and GFRP composites, and the results are shown in Figures 11 and 12.…”

Section: Resultsmentioning

confidence: 99%

“…On the other hand, the remaining part of the load acting on the polymer structures is stored elastically, and is called as the storage modulus. 43 In the current study, storage and loss moduli were calculated to determine the effect of LVI-induced local damages and thermoplastic veil interleaves on the performance characteristics of the CFRP and GFRP composites, and the results are shown in Figures 11 and 12. From the results, it was concluded that veil interleaves were highly effective on the storage modulus for the CFRP composites, and provided remarkable improvements for all configurations.…”

Section: Resultsmentioning

confidence: 99%

The influences of low‐velocity impact loading on the vibration responses of the carbon/glass fiber‐reinforced epoxy composites interleaved with various non‐woven thermoplastic veils

Tarih

Coskun

Yar

et al. 2023

J of Applied Polymer Sci

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Time‐dependent variable stresses that occur in composites subjected to mechanical and dynamic loads have devastating impacts on the material properties. Since these stresses reduce the service life, it is critical to detect and enhance structural responses before and after dynamic loadings. Therefore, the present study aimed to increase the toughness and delamination resistance of the conventional fiber‐reinforced composites by means of thermoplastic veil interleaves, thereby improving the vibration responses both before and after low‐velocity impact (LVI). In this context, carbon fiber (CF) and glass fiber (GF) reinforced epoxy composites interleaved with five different thermoplastic veils as Polyamide (PA), Polyetheretherketone (PEEK), Polyetherimide (PEI), Polyimide (PI) and Poly‐Phenylene Sulphide (PPS) were manufactured, and machined in accordance with the LVI standard. Composite specimens were subjected to the LVI tests, and then vibration tests were carried out for the non‐impacted and impacted specimens to determine dynamic properties. As a result, although thermoplastic veils generally have favorable effects on damping ratios of the GF composites, it has been revealed that these veils other than PPS and PI cause deterioration in CF composites. On the other hand, since vibration reduction depends on inherent damping and structural stiffness, this study also examined the storage‐to‐loss modulus ratios which denote the loss factors. In this respect, it was discovered that, while PPS, PEEK, PA, and PI thermoplastic veils included among the GF laminates ascend the loss factors of composites, only PI and PPS thermoplastic veils were shown to be positively effective in CF laminates. Moreover, CF and GF reinforced composites interleaved with thermoplastic veils generally exhibited higher natural frequency and lower damping ratio compared to the entirely CF or GF laminated composites. These results show that composite specimens gained bending stiffness due to local deformation hardening, and improved dynamic properties thanks to thermoplastic veil interleaved was attributed to increased toughness and delamination resistance.

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“…Since storage and loss modulus exemplify the elastic and viscous behavior of the polymer, respectively, they indicate the most elastic solid-like and viscose character. 39 Moreover, the obtained results showed that the G′ and G″ values for CPM-E (control sample without hydrocolloids) were higher than those for samples with pectin and less than those with the other hydrocolloids (agar, pectin, and xanthan). An increase in the pectin proportion decreases both G′ and G″ modules, showing the limit of viscose behavior.…”

Section: Particle Size Span and ζ-Potential Determinationmentioning

confidence: 87%

Effects of Hydrocolloid Agar, Gelatin, Pectin, and Xanthan on Physicochemical and Rheological Properties of Pickering Emulsions Stabilized by Canola Protein Microgel as a Potential Animal Fat Replacer

Rezaee

Aider-Kaci

Aïder

2022

ACS Food Sci. Technol.

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The effect of xanthan, agar, gelatin, and pectin on the stability, physicochemical, and rheological properties of the Pickering emulsions stabilized by canola protein microgel was studied in two ratios (1:1 and 2:1 as Pickering emulsion/hydrocolloids). Microscopic and FTIR analyses were used to explore the structure and possible interactions. Xanthan, gelatin, and agar increased G″ and G′ values. A controlled Pickering emulsion fabricated without any hydrocolloids became unstable after one day, while no phase separation was observed after adding xanthan, agar, and gelatin over 40 days of storage. Microscopic and particle size analyses showed that Pickering emulsions with xanthan had the smallest particle size. Rheological measurements showed that xanthan, agar, and gelatin increased the elasticity, solid-like, and viscose behavior of the emulsion. Emulsions with agar represented the most elastic solid-like and viscose character. It was concluded that such stable viscoelastic gel-like systems could find potential applications as fat replacers in developing novel healthy low-fat food products.

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Mechanical performance of poly(propylene carbonate)-based blends and composites

Cited by 7 publications

References 93 publications

Insight Into Solventless Production of Hydrophobically Modified Ethoxylated Urethanes (HEURs): The Role of Moisture Concentration, Reaction Temperature, and Mixing Efficiency

Insight Into Solventless Production of Hydrophobically Modified Ethoxylated Urethanes (HEURs): The Role of Moisture Concentration, Reaction Temperature, and Mixing Efficiency

The influences of low‐velocity impact loading on the vibration responses of the carbon/glass fiber‐reinforced epoxy composites interleaved with various non‐woven thermoplastic veils

Effects of Hydrocolloid Agar, Gelatin, Pectin, and Xanthan on Physicochemical and Rheological Properties of Pickering Emulsions Stabilized by Canola Protein Microgel as a Potential Animal Fat Replacer

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