The effect of chain extender structure on the enzymatic degradation of carbohydrate based polyurethane elastomers

The aim of this work was to determine the influence of clay nanoparticles on thermal properties of segmented polyurethanes based on hexamethylene- diisocyanate, aliphatic polycarbonate diol and 1,4-butanediol as chain extender. The organically modified particles of montmorillonite and bentonite were used as reinforcing fillers. The structure of elastomeric materials was varied either by diol type or chain extender content. The ratio of OH groups from diol and chain extender (R) was either 1 or 10. Thermal properties of prepared materials were determined using modulated differential scanning calorimetry (MDSC). Thermal stability of obtained elastomers has been studied by simultaneously thermogravimetry coupled with DSC. The glass transition temperature, Tg, of soft segments for all investigated samples was about -33?C. On the basis of DTG results, it was concluded that obtained materials were very stable up to 300?C.

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Tuning chain extender structure to prepare high-performance thermoplastic polyurethane elastomers

RSC Advances ◽

10.1039/c8ra02784f ◽

2018 ◽

Vol 8 (37) ◽

pp. 20701-20711 ◽

Cited By ~ 2

Author(s):

Wei Juan Xu ◽

Jian Jun Wang ◽

Shi Yu Zhang ◽

Jun Sun ◽

Chuan Xiang Qin ◽

...

Keyword(s):

High Performance ◽

Thermoplastic Polyurethane ◽

Chain Extender ◽

Polyurethane Elastomers ◽

Thermoplastic Polyurethane Elastomers ◽

Chain Extenders ◽

Thermo Stability

Ester-containing ferrocenyl diols are introduced as chain extenders to tune the polyurethane superstructure to optimize thermo-stability and elasticity simultaneously.

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Investigating the Properties and Structure of Polyurethane Elastomers with Monoethylene Glycol Chain Extender

Materials Science Forum ◽

10.4028/www.scientific.net/msf.986.18 ◽

2020 ◽

Vol 986 ◽

pp. 18-23

Author(s):

Patcharapon Somdee ◽

Timea Lassu-Kuknyo ◽

Csaba Konya ◽

Tamás Szabó ◽

Kálmán Marossy

Keyword(s):

Hard Segment ◽

Chain Extender ◽

Polypropylene Glycol ◽

Polyurethane Elastomers ◽

Elongation At Break ◽

Peak Intensity ◽

Hard Segment Content ◽

Polymeric Chains ◽

Monoethylene Glycol ◽

Hardness Values

The effect of monoethylene glycol (mEG) acting as chain extender in polypropylene glycol (PPG-4000) and 4,4ʹ-diphenylmethane diisocyanate (MDI) reaction was investigated. Polyurethane elastomers (PUR) were changed from flexible to rigid materials by varying the mEG content. Results show that Shore A and D hardness values trend to increase with increasing mEG content. It appears that increasing the chain extender content increases the hard segment content in the polyurethane structure. Moreover, increasing the mEG content increases Young’s modulus and the tensile strength of PUR, while elongation at break decreases. The chemical structure of the hard segment of PUR was characterized by Infrared (IR) spectroscopy. IR spectra exhibited the bands typical for PUR consisting of –NH, CH2– and C=O groups. The spectra reveal a few interactions between the polymeric chains that appear to be responsible for the shift of transmittance peak and decrease of some peak intensity. This may be due to the hard segment aggregating more to form domains in the PUR when mEG content was increased.

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Study on Mechanical Properties of Polyurethane Elastomers for Drum Scraper

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.284-286.2384 ◽

2011 ◽

Vol 284-286 ◽

pp. 2384-2387

Author(s):

Jin Cui Zhang ◽

Xi Jun Liu ◽

Tie Ning Ma

Keyword(s):

Mechanical Properties ◽

Chain Extender ◽

Glycol Ether ◽

Toluene Diisocyanate ◽

Chain Extension ◽

Molar Ratio ◽

Casting Method ◽

Polyurethane Elastomers ◽

Application Requirements

Polyurethane elastomers (PUE) were prepared by casting method using the prepolymer and the chain extender. In here, the prepolymer synthesized by using poly(tetramethylene glycol ether) (PTMG) and toluene diisocyanate (TDI), the chain extender was a mixture of 3,5-dimetylthio toluene diamine (E-300) and triethanolamine. The effects of the NCO concentration in prepolymer, the molar ratio of E-300/triethanolamine, and the chain extension coefficient of NCO/NH2 on the mechanical properties of the prepared PUE were studied. The results showed that the prepared PUE possesses excellent mechanical properties which can meet the drum scraper’s application requirements when the NCO concentration in prepolymer was 5.06% and the molar ratio of composite chain extender was 0.92/0.08.

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The Green Approach to the Synthesis of Bio-Based Thermoplastic Polyurethane Elastomers with Partially Bio-Based Hard Blocks

Materials ◽

10.3390/ma14092334 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2334

Author(s):

Ewa Głowińska ◽

Paulina Kasprzyk ◽

Janusz Datta

Keyword(s):

Mechanical Properties ◽

Thermoplastic Polyurethane ◽

Viscoelastic Behavior ◽

Polymeric Materials ◽

Building Blocks ◽

Chain Extender ◽

Sustainable Chemistry ◽

Polyurethane Elastomers ◽

Thermoplastic Polyurethane Elastomers ◽

Hard Segments

Bio-based polymeric materials and green routes for their preparation are current issues of many research works. In this work, we used the diisocyanate mixture based on partially bio-based diisocyanate origin and typical petrochemical diisocyanate for the preparation of novel bio-based thermoplastic polyurethane elastomers (bio-TPUs). We studied the influence of the diisocyanate mixture composition on the chemical structure, thermal, thermomechanical, and mechanical properties of obtained bio-TPUs. Diisocyanate mixture and bio-based 1,4-butanediol (as a low molecular chain extender) created bio-based hard blocks (HS). The diisocyanate mixture contained up to 75 wt % of partially bio-based diisocyanate. It is worth mentioning that the structure and amount of HS impact the phase separation, processing, thermal or mechanical properties of polyurethanes. The soft blocks (SS) in the bio-TPU’s materials were built from α,ω-oligo(ethylene-butylene adipate) diol. Hereby, bio-TPUs differed in hard segments content (c.a. 30; 34; 40, and 53%). We found that already increase of bio-based diisocyanate content of the bio-TPU impact the changes in their thermal stability which was measured by TGA. Based on DMTA results we observed changes in the viscoelastic behavior of bio-TPUs. The DSC analysis revealed decreasing in glass transition temperature and melting temperature of hard segments. In general, obtained materials were characterized by good mechanical properties. The results confirmed the validity of undertaken research problem related to obtaining bio-TPUs consist of bio-based hard building blocks. The application of partially bio-based diisocyanate mixtures and bio-based chain extender for bio-TPU synthesis leads to sustainable chemistry. Therefore the total level of “green carbons” increases with the increase of bio-based diisocyanate content in the bio-TPU structure. Obtained results constitute promising data for further works related to the preparation of fully bio-based thermoplastic polyurethane elastomers and development in the field of bio-based polymeric materials.

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