Influence of Glycols on the Glycolysis Process and the Structure and Properties of Polyurethane Elastomers

In this work, the influence of glycols on the glycolysis process and the properties of obtained polyurethanes were investigated. The glycolysates were produced via glycolysis of waste polyurethane foam in the reaction with one of the following glycols: 1,3-propanediol, 1,5-pentanediol, and 1,6-hexanediol.The reactions were carried out for different mass ratios of polyurethane wastes to glycolysis agent, i.e. 6:1, 8:1, and 10:1. Polyurethanes were synthesized from the obtained intermediates by a one-step method of mixing polymeric di-isocyanate and the glycolysis products with molecular masses ranging from 700 to 1000, while a polyol (Poles 55/20) was used as a chain elongation agent. The influence of glycolysates on tensile strength and elongation at break of polyurethanes was investigated using a Zwick universal tensile tester. Thermal decomposition of the obtained glycolysates and polyurethanes was investigated by thermogravimetry coupled with Fourier transform infrared spectroscopy. It has been found that of all used glycols, 1,6-hexanediol gives the best improvement in the thermal stability of polyurethanes during the glycolysis process. The mean hardness of polyurethanes decreases but rebound resilience increases with chain length of the glycol used for obtaining glycolysates.

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Green TPUs from Prepolymer Mixtures Designed by Controlling the Chemical Structure of Flexible Segments

International Journal of Molecular Sciences ◽

10.3390/ijms22147438 ◽

2021 ◽

Vol 22 (14) ◽

pp. 7438

Author(s):

Paulina Kasprzyk ◽

Ewa Głowińska ◽

Paulina Parcheta-Szwindowska ◽

Kamila Rohde ◽

Janusz Datta

Keyword(s):

Chemical Structure ◽

Melt Flow Index ◽

Molar Ratio ◽

Flow Index ◽

Step Method ◽

Elongation At Break ◽

Molecular Weights ◽

Trimethylene Glycol ◽

Hard Segments ◽

A Chain

This study concerns green thermoplastic polyurethanes (TPU) obtained by controlling the chemical structure of flexible segments. Two types of bio-based polyether polyols—poly(trimethylene glycol)s—with average molecular weights ca. 1000 and 2700 Da were used (PO3G1000 and PO3G2700, respectively). TPUs were prepared via a two-step method. Hard segments consisted of 4,4′-diphenylmethane diisocyanates and the bio-based 1,4-butanodiol (used as a chain extender and used to control the [NCO]/[OH] molar ratio). The impacts of the structure of flexible segments, the amount of each type of prepolymer, and the [NCO]/[OH] molar ratio on the chemical structure and selected properties of the TPUs were verified. By regulating the number of flexible segments of a given type, different selected properties of TPU materials were obtained. Thermal analysis confirmed the high thermal stability of the prepared materials and revealed that TPUs based on a higher amount of prepolymer synthesized from PO3G2700 have a tendency for cold crystallization. An increase in the amount of PO3G1000 at the flexible segments caused an increase in the tensile strength and decrease in the elongation at break. Melt flow index results demonstrated that the increase in the amount of prepolymer based on PO3G1000 resulted in TPUs favorable in terms of machining.

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Achievement of Both Mechanical Properties and Intrinsic Self-Healing under Body Temperature in Polyurethane Elastomers: A Synthesis Strategy from Waterborne Polymers

Polymers ◽

10.3390/polym12040989 ◽

2020 ◽

Vol 12 (4) ◽

pp. 989 ◽

Cited By ~ 3

Author(s):

Liangdong Zhang ◽

Teng Qiu ◽

Xiting Sun ◽

Longhai Guo ◽

Lifan He ◽

...

Keyword(s):

Tensile Strength ◽

Body Temperature ◽

Healing Process ◽

Waterborne Polyurethane ◽

Polymer Materials ◽

Self Healing ◽

Polyurethane Elastomers ◽

Elongation At Break ◽

Synthesis Strategy ◽

A Chain

Inspired by the growing demand for smart and environmentally friendly polymer materials, we employed 2,2′-disulfanediyldianiline (22DTDA) as a chain extender to synthesize a waterborne polyurethane (WPUR). Due to the ortho-substituted structure of the aromatic disulfide, the urea moieties formed a unique microphase structure in the WPUR, its mechanical strength was enhanced more 180 times relative to that of the material prepared without 22DTDA, and excellent self-healing abilities at body temperature in air or under ultrasound in water were obtained. If the self-healing process was carried out at 37 °C, 50 °C or under ultrasound, the ultimate tensile strength and elongation at break of the healed film could reach 13.8 MPa and 1150%, 15.4 MPa and 1215%, or 16 MPa and 1056%, respectively. Moreover, the WPUR films could be re-healed at the same fracture location over three cutting–healing cycles, and the recovery rates of the tensile strength and elongation at break remained almost constant throughout these cycles.

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Effect of Dynamic Crosslinking on Mechanical Properties of PP/EPDM Blends

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19932642 ◽

1993 ◽

Vol 58 (11) ◽

pp. 2642-2650 ◽

Cited By ~ 10

Author(s):

Zdeněk Kruliš ◽

Ivan Fortelný ◽

Josef Kovář

Keyword(s):

Mechanical Properties ◽

Impact Strength ◽

Shear Modulus ◽

High Impact ◽

Necessary Condition ◽

Step Method ◽

Melt Mixing ◽

One Step ◽

High Impact Strength ◽

Dynamic Curing

The effect of dynamic curing of PP/EPDM blends with sulfur and thiuram disulfide systems on their mechanical properties was studied. The results were interpreted using the knowledge of the formation of phase structure in the blends during their melt mixing. It was shown, that a sufficiently slow curing reaction is necessary if a high impact strength is to be obtained. Only in such case, a fine and homogeneous dispersion of elastomer can be formed, which is the necessary condition for high impact strength of the blend. Using an inhibitor of curing in the system and a one-step method of dynamic curing leads to an increase in impact strength of blends. From the comparison of shear modulus and impact strength values, it follows that, at the stiffness, the dynamically cured blends have higher impact strength than the uncured ones.

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Bismuth particles imbedded degradable nanohydrogel prepared by one-step method for tumor dual-mode imaging and chemo-photothermal combined therapy

Chemical Engineering Journal ◽

10.1016/j.cej.2019.122000 ◽

2019 ◽

Vol 375 ◽

pp. 122000 ◽

Cited By ~ 4

Author(s):

Yang Xuan ◽

Xian-Lin Song ◽

Xiao-Quan Yang ◽

Ruo-Yun Zhang ◽

Zi-Yu Song ◽

...

Keyword(s):

Combined Therapy ◽

Dual Mode ◽

Step Method ◽

One Step

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Bio-Based Polyurethane Networks Derived from Liquefied Sawdust

Materials ◽

10.3390/ma14113138 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3138

Author(s):

Kamila Gosz ◽

Agnieszka Tercjak ◽

Adam Olszewski ◽

Józef Haponiuk ◽

Łukasz Piszczyk

Keyword(s):

Biomass Conversion ◽

Structural Features ◽

Mechanical Analysis ◽

Process Efficiency ◽

Hydroxyl Number ◽

Step Method ◽

One Step ◽

Liquefaction Process ◽

The Fourier Transform ◽

Liquefaction Temperature

The utilization of forestry waste resources in the production of polyurethane resins is a promising green alternative to the use of unsustainable resources. Liquefaction of wood-based biomass gives polyols with properties depending on the reagents used. In this article, the liquefaction of forestry wastes, including sawdust, in solvents such as glycerol and polyethylene glycol was investigated. The liquefaction process was carried out at temperatures of 120, 150, and 170 °C. The resulting bio-polyols were analyzed for process efficiency, hydroxyl number, water content, viscosity, and structural features using the Fourier transform infrared spectroscopy (FTIR). The optimum liquefaction temperature was 150 °C and the time of 6 h. Comprehensive analysis of polyol properties shows high biomass conversion and hydroxyl number in the range of 238–815 mg KOH/g. This may indicate that bio-polyols may be used as a potential substitute for petrochemical polyols. During polyurethane synthesis, materials with more than 80 wt% of bio-polyol were obtained. The materials were obtained by a one-step method by hot-pressing for 15 min at 100 °C and a pressure of 5 MPa with an NCO:OH ratio of 1:1 and 1.2:1. Dynamical-mechanical analysis (DMA) showed a high modulus of elasticity in the range of 62–839 MPa which depends on the reaction conditions.

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Analysis and applicability of a new quartic polynomial one-step method for solving COVID-19 model

Journal of Physics Conference Series ◽

10.1088/1742-6596/1734/1/012019 ◽

2021 ◽

Vol 1734 ◽

pp. 012019

Author(s):

S E Fadugba ◽

V J Shaalini ◽

A A Ibrahim

Keyword(s):

Step Method ◽

Quartic Polynomial ◽

One Step

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Discussion on Repair Method of Concrete Highway Pavement

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.321-324.209 ◽

2013 ◽

Vol 321-324 ◽

pp. 209-212

Author(s):

Chun Yan Xia

Keyword(s):

Mechanical Properties ◽

Preparation Program ◽

Step Method ◽

Concrete Technology ◽

Concrete Material ◽

Repair Method ◽

Ordinary Concrete ◽

One Step ◽

Highway Pavement

nfluences on properties of the concrete highway pavement were analyzed in this paper, and the optimal formulation materials were gotten to use in the repair of used-broken cement blocks in the experiment. Polyurethane concrete material was prepared, combing the ordinary concrete technology with one-step method of the synthesis of polyurethane hard bubble, and then its mechanical properties of the relevant parameters were measured to determine the optimal preparation program. The results show that the polyurethane concrete also has sufficiently good mechanical properties while it has the characteristic of fast patching.

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