Enhanced foaming behaviors and compression properties of thermoplastic polyurethane via constructing micro-crosslinking structure assisted by chain extender

Zhuang, Hui-Tong; Zhang, Li; Bao, Jin-Biao

doi:10.1007/s00396-022-04960-8

Cited by 4 publications

(3 citation statements)

References 45 publications

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“…As mentioned above, the foaming temperature is a critical factor to control foam ex pansion, and a mountain-shaped relationship between foaming temperature and foam expansion ratio has been widely reported [38]. Figure 7 summarizes the optimum foamin temperature (Tof) of TPU as a function of sample hardness [6,16,21,[42][43][44][45][46][47][48][49][50], where the com pressed CO2 was used as the blowing agent. It is seen that an increase in resin hardnes tends to increase the Tof of TPU foams.…”

Section: Foaming Behaviors Of Hd-tpu Sheets 231 Effect Of Saturation ...mentioning

confidence: 99%

Supercritical Fluid Microcellular Foaming of High-Hardness TPU via a Pressure-Quenching Process: Restricted Foam Expansion Controlled by Matrix Modulus and Thermal Degradation

Chen

Jiang

et al. 2022

Molecules

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High-hardness thermoplastic polyurethane (HD-TPU) presents a high matrix modulus, low-temperature durability, and remarkable abrasion resistance, and has been used in many advanced applications. However, the fabrication of microcellular HD-TPU foam is rarely reported in the literature. In this study, the foaming behavior of HD-TPU with a hardness of 75D was investigated via a pressure-quenching foaming process using CO2 as a blowing agent. Microcellular HD-TPU foam with a maximum expansion ratio of 3.9-fold, a cell size of 25.9 μm, and cell density of 7.8 × 108 cells/cm3 was prepared, where a high optimum foaming temperature of about 170 °C had to be applied with the aim of softening the polymer’s matrix modulus. However, the foaming behavior of HD-TPU deteriorated when the foaming temperature further increased to 180 °C, characterized by the presence of coalesced cells, microcracks, and a high foam density of 1.0 g/cm3 even though the crystal domains still existed within the matrix. The cell morphology evolution of HD-TPU foam was investigated by adjusting the saturation time, and an obvious degradation occurred during the high-temperature saturation process. A cell growth mechanism of HD-TPU foams in degradation environments was proposed to explain this phenomenon based on the gas escape through the defective matrix.

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Section: Foaming Behaviors Of Hd-tpu Sheets 231 Effect Of Saturation ...mentioning

confidence: 99%

Supercritical Fluid Microcellular Foaming of High-Hardness TPU via a Pressure-Quenching Process: Restricted Foam Expansion Controlled by Matrix Modulus and Thermal Degradation

Chen

Jiang

et al. 2022

Molecules

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show abstract

“…In order to analyze the sensitivity of the grout expansion ratio to the changes in concentration of different components, we introduced R j−i as the rate of change in the grout volume expansion ratio when the concentration of different components changed. The calculation formula is as follows: R j−i = S j − S i S i (18) where R j−i is the change rate of the expansion ratio of the grout; S j is the expansion ratio of the grout after the component concentration increases; S i is the expansion ratio of the grout before the component concentration increases.…”

Section: Analysis Of the Influence Of Various Factors On The Expansio...mentioning

confidence: 99%

“…Researchers have conducted investigations into the impact of certain components on both the foaming process of polyurethane and its mechanical properties. Zhuang et al [18] observed that incorporating a chain extender into the TPU matrix enhances the branching of the molecular chain, resulting in an expansion rate and compressive strength of composite foam that are two to threefold that of the unmodified sample. Lai et al [19] studied the effects of varying chain extender levels on the mechanical and foaming properties of thermoplastic polyurethane materials.…”

Section: Introductionmentioning

confidence: 99%

Impact of Composition Ratio on the Expansion Behavior of Polyurethane Grout

Li,

Peng,

et al. 2024

Materials

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Different formulations of foaming polyurethane grout offer controlled expansion rates. This is crucial for precision in filling voids without exerting excessive pressure on surrounding structures, which could potentially cause damage. This study focuses on the impact of composition on the expansion performance of tailor-made polyurethane grouting materials. Initially, multiple unknown chemical reaction kinetic parameters were identified by combining free expansion tests, which involved measuring density and temperature changes, with the particle swarm optimization algorithm. A numerical simulation, integrating chemical kinetic models and fluid flow equations, was established to replicate the free expansion process of polyurethane grout in a cup, aligning with our experimental results. Subsequently, we analyzed the polymerization process of polyurethane grout with varying compositions to determine the effect of composition ratios on grout expansion. Our findings reveal that the expansion ratio of foaming polyurethane is predominantly influenced by the concentrations of physical and chemical foaming agents, followed by isocyanate concentration. Polyol, in contrast, exerts a relatively minor influence. Furthermore, the solubility of the physical foaming agent in the grout determines both its maximum allowable concentration and its maximum contribution to volume increase. This study provides valuable insights for the design and selection of polyurethane grout components tailored to diverse applications.

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Empowering PLA Bioplastics: Elevating applications horizon through groundbreaking Eco-Innovative Fibrillation, chain Extension, and crosslinking techniques

Reza Monfared,

Tuccitto,

Omranpour

et al. 2024

Chemical Engineering Journal

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Enhanced foaming behaviors and compression properties of thermoplastic polyurethane via constructing micro-crosslinking structure assisted by chain extender

Cited by 4 publications

References 45 publications

Supercritical Fluid Microcellular Foaming of High-Hardness TPU via a Pressure-Quenching Process: Restricted Foam Expansion Controlled by Matrix Modulus and Thermal Degradation

Supercritical Fluid Microcellular Foaming of High-Hardness TPU via a Pressure-Quenching Process: Restricted Foam Expansion Controlled by Matrix Modulus and Thermal Degradation

Impact of Composition Ratio on the Expansion Behavior of Polyurethane Grout

Empowering PLA Bioplastics: Elevating applications horizon through groundbreaking Eco-Innovative Fibrillation, chain Extension, and crosslinking techniques

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