Investigation of Hyperbranced Polyesters with Different Generation and their Application in Waterborne Polyurethanes

2012 ◽  
Vol 152-154 ◽  
pp. 91-96 ◽  
Author(s):  
Dong Ya Yang ◽  
Li Han ◽  
Han Qing Zhang ◽  
Feng Xian Qiu
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Crosslinking Agent ◽  
Waterborne Polyurethane ◽  
Hyperbranched Polyester ◽  
Aqueous Dispersions ◽  
Hyperbranched Polyesters ◽  
Waterborne Polyurethanes ◽  
Lower Viscosity ◽  
Polyurethane Dispersions

The 1st, 2nd and 3rd generations of hydroxyl-terminated hyperbranched polyesters (HBPE-1, HBPE-2, and HBPE-3) were synthesized. A3rd generation hyperbranched polyester (HBPE-3) was used as original crosslinking agent to prepared hyperbranched waterborne polyurethane dispersions (HPU). FTIR spectra confirmed that this reaction really took place. The experimental data indicated that, compared with the linear one, the hyperbranched HPU aqueous dispersions exhibited lower viscosity, and larger particle size. For the hyperbranched HPU films, mechanical properties were obviously enhanced.

scholarly journals The Puncture and Water Resistance of Polyurethane- Impregnated Fabrics after UV Weathering

Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 15
Author(s):  
Antonella Patti ◽  
Domenico Acierno
Keyword(s):  
Experimental Data ◽  
Uv Radiation ◽  
Water Resistance ◽  
Uv Light ◽  
Crosslinking Agent ◽  
Waterborne Polyurethane ◽  
Impregnation Method ◽  
Polyurethane Dispersion ◽  
Spectroscopic Analyses ◽  
Before And After

Polyurethane is a polymer adaptable to different scientific and industrial requirements; nevertheless it is also extremely susceptible to UV radiation, which compromises the physical and mechanical functionality. In this framework, our study investigated the effect of waterborne polyurethane dispersion (WPUD) applied to a polyester (PET)-based fabric, through the impregnation method, on the puncturing and water resistance of the pristine material, before and after UV weathering. Results confirmed an increment of both features in the prepared fabrics, attributed to the PUR textile treatment; but a partially loss of the gained properties in the samples due to the UV weathering. In order to improve the efficiency of the impregnating dispersions, in protecting the durability of the treated materials, the addition of different UV light stabilizers, or/and of crosslinking agent into WPUD was also tested. From the experimental data, it can be concluded that formulations based on WPUD, containing both the crosslinker and UV organic absorber, have displayed an increment of their perforation and water resistance for the treated samples with respect to the starting textile, and contemporary have preserved the features against the UV light. Finally, microscopic and spectroscopic analyses have been performed as further characterization techniques of the samples surface.

Synthesis of MDI-50 and Tung Oil-Based Non-Ionic Waterborne Polyurethanes

2016 ◽  
Vol 848 ◽  
pp. 160-166
Author(s):  
Bai Xia Ren ◽  
Hua Fen Wang ◽  
Zhi Yong Ren ◽  
Wen Tao Liu ◽  
Lei Jiang ◽  
...  
Keyword(s):  
Surface Tension ◽  
Soft Segment ◽  
Waterborne Polyurethane ◽  
Lower Surface ◽  
Molecular Structures ◽  
Proton Nuclear Magnetic Resonance ◽  
Feed Ratio ◽  
Tung Oil ◽  
Waterborne Polyurethanes ◽  
Polyurethane Dispersions

A series of MDI-50 based non-ionic waterborne polyurethane dispersions (MDI-NPUD) were prepared by the mixing of 2,4’-diphenylmethane diisocianate (2,4’-MDI) and 4,4’-MDI (MDI-50) which reacted with hydroxylated tung oil (HTO) and polyethylene glycol-800 (PEG-800), Fourier Transform Infrared Spectroscopy (FTIR) and Proton-Nuclear Magnetic Resonance (1H-NMR) were used to characterize and analyze their molecular structures. The results indicated that MDI-50 and HTO were introduced as hard segment while PEG acted as soft segment. The surface tension, Hydrophile-Lipophile Balance (HLB) and stability were investigated. All MDI-NPUDs had much lower surface tension than the dicyclohexyl methane diisocyanate (HMDI) based NPUD (HMDI-NPUD). By changing the feed ratio of MDI-NPUD, the properties of MDI-NPUD could be controlled

Study on the Synthesis and Properties of Biodegradable Waterborne Polyurethane

2012 ◽  
Vol 554-556 ◽  
pp. 130-135 ◽  
Author(s):  
Fei Liang ◽  
Bei Qin ◽  
Ying Yang ◽  
Min Jia
Keyword(s):  
Mechanical Properties ◽  
Hydrolytic Degradation ◽  
Waterborne Polyurethane ◽  
Molar Ratio ◽  
Waterborne Polyurethanes ◽  
Soft Segments ◽  
Hard Segments ◽  
R Value ◽  
Medical Material ◽  
Step Polymerization

Taking L-Lysine Diisocyanate (LDI) as hard segments, poly-ε-caprolactone diol (PCL) as soft segments, a kind of nontoxic and biodegradable waterborne polyurethanes were synthesized using two-step polymerization. And then the effects of isocyanate/macroglycol molar ratio(NCO/OH, R value), the 1,4-butylene glycol (BDO) content and prepolymerization temperature on the properties of waterborne polyurethanes were investigated. The experimental results showed that when R value is 1.5, the BDO content used is 4% and the reaction temperature is 80°C, the products prepared were best in application. The mechanical property tests showed that it has good mechanical properties, tensile strength is up to 46.5MPa and the loss amounts of the hydrolytic degradation after 80 days is 42%. The waterborne polyurethanes prepared have excellent biodegradability, which can be widely used as a biological medical material.

Recent developments in waterborne polyurethane dispersions (WPUDs): a mini-review on thermal and mechanical properties improvement

2021 ◽  
Author(s):  
Swapnil M. Vaidya ◽  
Simran M. Jadhav ◽  
Mitesh J. Patil ◽  
Siddhesh U. Mestry ◽  
Umesh R. Mahajan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Waterborne Polyurethane ◽  
Thermal And Mechanical Properties ◽  
Recent Developments ◽  
Polyurethane Dispersions

scholarly journals Chemical and Thermo-Mechanical Properties of Waterborne Polyurethane Dispersion Derived from Jatropha Oil

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 795
Author(s):  
Sariah Saalah ◽  
Luqman Chuah Abdullah ◽  
Min Min Aung ◽  
Mek Zah Salleh ◽  
Dayang Radiah Awang Biak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Film Formation ◽  
Consumer Preference ◽  
Waterborne Polyurethane ◽  
Crosslinking Density ◽  
Jatropha Oil ◽  
Free Standing ◽  
Polyurethane Dispersion ◽  
Total Volatile Organic Compounds ◽  
Polyurethane Dispersions

Nowadays, there is a significant trend away from solvent-based polyurethane systems towards waterborne polyurethane dispersions due to government regulations requiring manufacturers to lower total volatile organic compounds, as well as consumer preference for more environmentally friendly products. In this work, a renewable vegetable oil-based polyol derived from jatropha oil was polymerized with isophorone diisocyanate and dimethylol propionic acid to produce anionic waterborne polyurethane dispersion. Free standing films with up to 62 wt.% bio-based content were successfully produced after evaporation of water from the jatropha oil-based waterborne polyurethane (JPU) dispersion, which indicated good film formation. The chemical and thermo-mechanical properties of the JPU films were characterized. By increasing the OH numbers of polyol from 161 mgKOH/g to 217 mgKOH/g, the crosslinking density of the JPU was significantly increased, which lead to a better storage modulus and improved hydrophobicity. Overall, JPU produced from polyol having OH number of 217 mgKOH/g appears to be a promising product for application as a binder for wood and decorative coatings.

Preparation and Characterization of Castor Oil-Based Cationic Waterborne Polyurethane

2015 ◽  
Vol 1090 ◽  
pp. 3-7
Author(s):  
Kai Liu ◽  
Song Ping Zhang ◽  
Zhi Guo Su ◽  
Guang Hui Ma
Keyword(s):  
Castor Oil ◽  
Hard Segment ◽  
Waterborne Polyurethane ◽  
Gravimetric Analysis ◽  
Waterborne Polyurethanes ◽  
Hard Segment Content ◽  
Ir Analysis ◽  
Hard Segments ◽  
Polyurethane Dispersions

A variety of castor oil-based cationic polyurethane dispersions (PUDs) were synthesized. The effects of hard segment content on the properties of PUDs and the resulting polyurethane films were investigated by mastersizer, Fourier transform infrared (IR), thermal gravimetric analysis (TGA) and stress-strain test. As the hard segment content increased from 37.1 to 45.6 wt %, the particle size of the PUDs increased from 10 to 190 nm. IR analysis showed that hydrogen bonding between hard segments enhanced with the increase of hard segment content. For this enhancement the films had an increased tensile strength from 2.0 to 9.4 MPa and an improved glass transition temperature (Tg) from 48oC to 75oC. TGA showed the films were thermally stable up to 200oC and had biphasic degradation at around 330oC and 440oC. The versatile castor oil-based cationic waterborne polyurethanes are promising in applications as adhesives and coatings.

scholarly journals Optimization of Collagen Chemical Crosslinking to Restore Biocompatibility of Tissue-Engineered Scaffolds

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 832
Author(s):  
Mohammad Mirazul Islam ◽  
Dina B. AbuSamra ◽  
Alexandru Chivu ◽  
Pablo Argüeso ◽  
Claes H. Dohlman ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Crosslinking Agent ◽  
Collagen Scaffold ◽  
Human Monocyte ◽  
Subsequent Treatment ◽  
Sodium Metabisulfite ◽  
Corneal Tissue ◽  
Dependent Manner ◽  
Collagen Scaffolds ◽  
Enzymatic Stability

Collagen scaffolds, one of the most used biomaterials in corneal tissue engineering, are frequently crosslinked to improve mechanical properties, enzyme tolerance, and thermal stability. Crosslinkers such as 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) are compatible with tissues but provide low crosslinking density and reduced mechanical properties. Conversely, crosslinkers such as glutaraldehyde (GTA) can generate mechanically more robust scaffolds; however, they can also induce greater toxicity. Herein, we evaluated the effectivity of double-crosslinking with both EDC and GTA together with the capability of sodium metabisulfite (SM) and sodium borohydride (SB) to neutralize the toxicity and restore biocompatibility after crosslinking. The EDC-crosslinked collagen scaffolds were treated with different concentrations of GTA. To neutralize the free unreacted aldehyde groups, scaffolds were treated with SM or SB. The chemistry involved in these reactions together with the mechanical and functional properties of the collagen scaffolds was evaluated. The viability of the cells grown on the scaffolds was studied using different corneal cell types. The effect of each type of scaffold treatment on human monocyte differentiation was evaluated. One-way ANOVA was used for statistical analysis. The addition of GTA as a double-crosslinking agent significantly improved the mechanical properties and enzymatic stability of the EDC crosslinked collagen scaffold. GTA decreased cell biocompatibility but this effect was reversed by treatment with SB or SM. These agents did not affect the mechanical properties, enzymatic stability, or transparency of the double-crosslinked scaffold. Contact of monocytes with the different scaffolds did not trigger their differentiation into activated macrophages. Our results demonstrate that GTA improves the mechanical properties of EDC crosslinked scaffolds in a dose-dependent manner, and that subsequent treatment with SB or SM partially restores biocompatibility. This novel manufacturing approach would facilitate the translation of collagen-based artificial corneas to the clinical setting.

scholarly journals Coatings with recycled polyvinyl butyral on polyester and polyamide mono- and multifilament yarns

2021 ◽  
Author(s):  
Rike Brendgen ◽  
Carsten Graßmann ◽  
Thomas Grethe ◽  
Boris Mahltig ◽  
Anne Schwarz-Pfeiffer
Keyword(s):  
Mechanical Properties ◽  
Chemical Resistance ◽  
Crosslinking Agent ◽  
Polyvinyl Butyral ◽  
Polymer Dispersion ◽  
Safety Glass ◽  
Enhanced Properties ◽  
Multifilament Yarns ◽  
Textile Coating ◽  
Recycled Material

AbstractPolyvinyl butyral is used in safety glass interlayers, mainly in car windshields. Legislative regulations require a recycling of cars after their lifetime and therefore also their safety glass. This causes the availability of recycled polyvinyl butyrate (r-PVB) originated from safety glass interlayers. Due to deteriorated optical properties, such as the transparency, and unknown amounts of plasticizers, it is challenging to reuse the recycled material in new windshields. Therefore, it is of particular interest to find new fields of application for r-PVB, such as the usage as a textile coating. In this research, r-PVB was investigated as a material for yarn coating. Polyester and polyamide mono- and multifilament yarns were coated continuously with solely a polymer dispersion and with mixtures of crosslinking agent and polymer dispersion. Crosslinked r-PVB coatings showed enhanced properties toward abrasion and chemical resistance. Coatings without the crosslinking agent showed a diminished abrasion resistance and could be washed off with ethanol. Mechanical properties of the monofilaments were influenced by the r-PVB coating in general. However, varying concentrations of the crosslinking agent did not affect the mechanical properties.

scholarly journals An Additive Model to Predict the Rheological and Mechanical Properties of Polypropylene Blends Made by Virgin and Reprocessed Components

Recycling ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 2
Author(s):  
Francesco Paolo La Mantia ◽  
Maria Chiara Mistretta ◽  
Vincenzo Titone
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Additive Model ◽  
Industrial Process ◽  
Theoretical Predictions ◽  
Experimental Values ◽  
Polypropylene Blends ◽  
Polypropylene Sample

In this work, an additive model for the prediction of the rheological and mechanical properties of monopolymer blends made by virgin and reprocessed components is proposed. A polypropylene sample has been reprocessed more times in an extruder and monopolymer blends have been prepared by simulating an industrial process. The scraps are exposed to regrinding and are melt reprocessed before mixing with the virgin polymer. The reprocessed polymer is, then, subjected to some thermomechanical degradation. Rheological and mechanical experimental data have been compared with the theoretical predictions. The results obtained showed that the values of this simple additive model are a very good fit for the experimental values of both rheological and mechanical properties.

scholarly journals Rheometer Evidences for the Co-Curing Effect of a Bismaleimide in Conjunction with the Accelerated Sulfur on Natural Rubber/Chloroprene Rubber Blends

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1510
Author(s):  
Marek Pöschl ◽  
Shibulal Gopi Sathi ◽  
Radek Stoček ◽  
Ondřej Kratina
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Tensile Properties ◽  
Crosslinking Agent ◽  
Alder Reaction ◽  
Diels Alder ◽  
Ene Reactions ◽  
Rubber Blends ◽  
Diels Alder Reaction ◽  
Chloroprene Rubber

The rheometer curing curves of neat natural rubber (NR) and neat chloroprene rubber (CR) with maleide F (MF) exhibit considerable crosslinking torque at 180 °C. This indicates that MF can crosslink both these rubbers via Alder-ene reactions. Based on this knowledge, MF has been introduced as a co-crosslinking agent for a 50/50 blend of NR and CR in conjunction with accelerated sulfur. The delta (Δ) torque obtained from the curing curves of a blend with the addition of 1 phr MF was around 62% higher than those without MF. As the content of MF increased to 3 phr, the Δ torque was further raised to 236%. Moreover, the mechanical properties, particularly the tensile strength of the blend with the addition of 1 phr MF in conjunction with the accelerated sulfur, was around 201% higher than the blend without MF. The overall tensile properties of the blends cured with MF were almost retained even after ageing the samples at 70 °C for 72 h. This significant improvement in the curing torque and the tensile properties of the blends indicates that MF can co-crosslink between NR and CR via the Diels–Alder reaction.

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