Crystallization of hard segment domains with the presence of butane for microcellular thermoplastic polyurethane foams

Hossieny, Nemat; Barzegari, Mohamad Reza; Nofar, Mohammadreza; Mahmood, S.H.; Park, Chul

doi:10.1016/j.polymer.2013.12.028

Cited by 103 publications

(80 citation statements)

References 71 publications

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“…For the formation of TPU foam, many blowing agents have been used such as butane , azodicarbonamide , and NaHCO 3 [19]. It should be noted that most of them are toxic, which furtherly lead the polymer matrix to additional degradation .…”

Section: Introductionmentioning

confidence: 99%

Preparation of microcellular thermoplastic polyurethane (TPU) foam and its tensile property

Wang

Zheng

et al. 2017

Polymer Engineering & Sci

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In this study, the thermoplastic polyurethane (TPU) composed of same type soft and hard segment while different hard segment contents was selected to prepare microcellular TPU foams, using CO2 as the physical blowing agent in a batch foaming process. The TPU with high hard segment content (i.e., 36.1 wt%) exhibited high complex viscosity, low initial CO2 content, and microcrystalline region, while the others (i.e., 32.0 and 26.1 wt%) showed opposite results. The cell structure evolution of TPU foams with the foaming temperature and the foaming time showed that the low hard segment content was benefiting for the expansion ratio, whereas the high hard segment content generated the microcrystalline region acting as the nucleating site to improve the cell density. The tensile behavior of prepared TPU foams was investigated in the cyclic tensile test. It was observed that the hysteresis and residual strain increased with the increasing hard segment content, furtherly exhibited lower value compared to TPU. Moreover, scanning electron microscopy, differential scanning calorimeter, and infrared spectra were used to reveal the microstructure after tensile test. The results indicated that the cell structures had a significant contribution to improve the elasticity, resulting from the protection of cells on the hard domains. POLYM. ENG. SCI., 58:E158–E166, 2018. © 2017 Society of Plastics Engineers

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Section: Introductionmentioning

confidence: 99%

Preparation of microcellular thermoplastic polyurethane (TPU) foam and its tensile property

Wang

Zheng

et al. 2017

Polymer Engineering & Sci

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“…An HS consists of urethane groups, while a SS consists of a polyol that includes ester groups or ether groups. TPU is featured as having an elasticity of rubber as well as high mechanical properties of plastic materials [4][5][6]. Therefore, using TPU effectively improves the mechanical properties and impact strength [7].…”

Section: Introductionmentioning

confidence: 99%

The Effects of Thermoplastic Polyurethane on the Structure and Mechanical Properties of Modified Polypropylene Blends

2017

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Abstract:In this study, a melt-compounding process was used to produce ordinary polypropylene (PP)/thermoplastic polyurethane (TPU) blends and modified impact-resistant polypropylene (MPP)/TPU blends. The influences of TPU on the blending morphology, melting behavior, crystallization behavior, and mechanical properties of these blends were investigated. Differential scanning calorimetry results show that using TPU influences the crystalline and melting behavior of PP/TPU blends, but not of MPP/TPU blends. X-ray diffraction analysis indicated that the presence of TPU neither influences the crystalline structure of PP nor creates new crystalline peaks. The mechanical property test results revealed that PP/TPU blends demonstrate better tensile strength, Young's modulus, and flexural strength, whereas MPP/TPU blends exhibit higher energy absorption and impact strength. This study is expected to produce optimal products with the preferred continuous and dispersive phases for end users, designing multiple and compatible functionalities of blends.

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“…Foaming with liquid CO 2 has been introduced [9][10][11][12] ; however, it requires a complicated storage and metering system for CO 2 . Volatile hydrocarbons such as cyclopentane belong to climatefriendly blowing agents, [13][14][15] although they are highly flammable. Therefore, the exploration of a safe, climate-and user-friendly blowing agent is very urgent in the PU foam industry.…”

Section: Introductionmentioning

confidence: 99%

Climate‐friendly polyurethane blowing agent based on a carbon dioxide adduct from palmitic acid grafted polyethyleneimine

Long

Sun

Dong

et al. 2016

J of Applied Polymer Sci

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To explore a new blowing agent for polyurethanes (PUs), palmitic acid was grafted onto a branched polyethyleneimine (bPEI; weight-average molecular weight 5 25,000 Da) via N,N 0 -carbonyldiimidazole condensation to form a hydrophobically modified bPEI [palmitic acid grafted branched polyethyleneimine (C 16 -bPEI)] with a grafting rate of 12%. A CO 2 adduct of C 16 -bPEI, which trapped 16.8% CO 2 in it, was synthesized from C 16 -bPEI. The long alkyl chain grafting improved the dispersibility of the CO 2 adduct in the PU raw materials and favored a homogeneous release of CO 2 to blow PUs during the exothermic foaming process. The preliminary results show that the foams possessed a density of 72.0 kg/m 3 and a compressive strength of 246 kPa; this matched the required values of foams for the thermal insulation of underground steel pipes. This new blowing agent emitted nothing but CO 2 to the atmosphere, so it will not promote ozone depletion and will avoid global warming problems that are associated with traditional blowing agents such as chlorofluorocarbons and hydrochloroflourocarbons.

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Crystallization of hard segment domains with the presence of butane for microcellular thermoplastic polyurethane foams

Cited by 103 publications

References 71 publications

Preparation of microcellular thermoplastic polyurethane (TPU) foam and its tensile property

Preparation of microcellular thermoplastic polyurethane (TPU) foam and its tensile property

The Effects of Thermoplastic Polyurethane on the Structure and Mechanical Properties of Modified Polypropylene Blends

Climate‐friendly polyurethane blowing agent based on a carbon dioxide adduct from palmitic acid grafted polyethyleneimine

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