Waterborne polyurethanes from CO2 based polyols with comprehensive hydrolysis/oxidation resistance

2016 ◽  
Vol 18 (2) ◽  
pp. 524-530 ◽  
Author(s):  
Jin Wang ◽  
Hongming Zhang ◽  
Yuyang Miao ◽  
Lijun Qiao ◽  
Xianhong Wang ◽  
...  
Keyword(s):  
Oxidation Resistance ◽  
Mechanical Performance ◽  
Waterborne Polyurethanes ◽  
Water Borne

Water-borne CO2-based polyurethanes with excellent mechanical performance and hydrolysis/oxidation resistance are prepared from CO2.

Effects of Water-Borne Polyurethane on Calcium Silicate Hydrate and Toughness of Properties of Cementitious Composites

2012 ◽  
Vol 619 ◽  
pp. 545-552
Author(s):  
Bei Ding ◽  
Xia Zhang ◽  
Dong Liang Zhou ◽  
Chan Wen Miao
Keyword(s):  
Mechanical Performance ◽  
Concrete Strength ◽  
Harmful Effect ◽  
Impact Resistance ◽  
29Si Nmr ◽  
Size Change ◽  
Block Polymer ◽  
Chain Conformations ◽  
The Impact ◽  
Water Borne

A novel kind of block polymer with characteristics of rod-like chain conformations-water-borne polyurethane (PUA) was synthesized by incorporate polyacrylate (PA) into the PU chain to prepare an aqueous polyurethane-polyacrylate (PUA) hybrid emulsion with core-shell structure. The interactions between Water-borne PUA and C-S-H nanostructure, which include intercalation and the polymerization degree of C-S-H silicate chains, were studied by small angle X-ray diffraction spectra and 29Si NMR spectra, respectly. The influences of water-borne PUA on mechanical performance of C-S-H were investigated experimentally. The small XRD results show that no evidence is observed for any fundamental size change in the C-S-H particles that have been formed in the presence of polymer. The NMR results indicate that there is a significant increase in the Q2/Q1 ratio ranging from 0.5 for pure C-S-H to 2.2 for PUA-C-S-H, respectively. The degree of silicate polymerization increases from 3.0 for pure C-S-H to 6.4 for PUA-C-S-H by calculation. PUA had minimal harmful effect on the compressive strength whereas the flexural strength was increased by 23.2% with dosage of 0.5% and 23.3% with dosage of 1.0%, respectively.The fracture energy ratios of concrete with a dosage of PUA less than 1% are greatly improved more than double with the decreasing of concrete strength less than 10%. The water-borne PUA also enhances the impact resistance of concrete. The impact energy consumption of samples with PUA increase nearly three times more than reference samples, also better than samples with PP fiber.

Cr-incorporated uranium nitride composite fuels with enhanced mechanical performance and oxidation resistance

2021 ◽  
pp. 153486
Author(s):  
Kun Yang ◽  
Erofili Kardoulaki ◽  
Dong Zhao ◽  
Bowen Gong ◽  
Andre Broussard ◽  
...  
Keyword(s):  
Oxidation Resistance ◽  
Mechanical Performance ◽  
Uranium Nitride

scholarly journals Surface Modification of Graphene for Use as a Structural Fortifier in Water-Borne Epoxy Coatings

Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 754 ◽  
Author(s):  
Liu ◽  
Xia ◽  
Zehri ◽  
Ye ◽  
Wang ◽  
...  
Keyword(s):  
Superhydrophobic Surface ◽  
Epoxy Resins ◽  
Mechanical Performance ◽  
Diazonium Salt ◽  
Hydroxyl Groups ◽  
Curing Process ◽  
Functionalized Graphene ◽  
Carbon Allotrope ◽  
Surface Modified ◽  
Water Borne

Graphene, the typical two-dimensional sp2 hybridized carbon allotrope, is widely used as a filler for improving the mechanical performance of polymers. However, its superhydrophobic surface makes it a big challenge to obtain stable graphene dispersions, especially in water-borne systems. On the contrary, graphene oxide (GO) shows excellent dispersibility in water, but strong oxidants and acids destroy its structure and degrade its mechanical properties. This largely limits its application in water-borne coatings. In this work, graphene from mechanical exfoliation was surface modified by p-aminophenol derived diazonium salt to achieve a homogenous dispersion. Moreover, the hydroxyl groups in p-aminophenol are able to combine with epoxy resins during the curing process to improve mechanical performance of the final coatings. The result shows that functionalized graphene shows a lower coefficient of friction and better abrasion resistance compared to GO.

Effect of coatings on oxidation resistance and mechanical performance of Ti60 alloy

1998 ◽  
Vol 255 (1-2) ◽  
pp. 133-138 ◽  
Author(s):  
Zhaolin Tang ◽  
Fuhui Wang ◽  
Weitao Wu ◽  
Qingjiang Wang ◽  
Dong Li
Keyword(s):  
Oxidation Resistance ◽  
Mechanical Performance

scholarly journals Preparation and Properties of Biobased, Cationic, Waterborne Polyurethanes Dispersions from Castor Oil and Poly (Caprolactone) Diol

2021 ◽  
Vol 11 (11) ◽  
pp. 4784
Author(s):  
Ying Li ◽  
Sichong Chen ◽  
Jun Shen ◽  
Siqi Zhang ◽  
Ming Liu ◽  
...  
Keyword(s):  
Adhesive Strength ◽  
Castor Oil ◽  
Mechanical Performance ◽  
Aqueous Dispersion ◽  
Waterborne Polyurethane ◽  
Peel Strength ◽  
Waterborne Polyurethanes ◽  
Film Forming ◽  
Poly Caprolactone ◽  
Positive Effect

Biobased cationic waterborne polyurethanes (WPUs) were prepared using isophorone diisocyanate (IPDI), N-methyl diethanolamine (N-MDEA), polycaprolactone (PCL) diol, hydrochlotic acid (HCl), and 1,4-butanediol (BDO). To improve the mechanical performance and adhesive strength of the waterborne polyurethane films, different amounts of castor oil (CO) acting as a cross-linking agent were incorporated in the polyurethane structure. The structures of the waterborne polyurethanes were assessed by Fourier-transform infrared spectroscopy (FTIR). The combination of CO had a positive effect on the dispersion and stability properties of WPUs. WPUs containing higher content of CO demonstrated a remarkable enhancement in homogeneity among particles. The stable aqueous dispersion was obtained even when N-MDEA loading was as low as 3.2 wt%; a bonus of this low hydrophilic moiety was the excellent adhesive strength, whose T-peel strength could reach up to 36.8 N/25 mm, about 114% higher than that of WPU (17.2 N/25 mm) without any CO content. The elongation at break of CO7.40%-WPU was 391%. In addition, the fracture mechanism of the waterborne polyurethane films transformed from the brittle failure to the ductile fracture. The experiment results showed the CO-modified WPUs displayed excellent film-forming property, flexibility, and adhesion, which can be employed for constructing the eco-friendly, biodegradable, cationic, waterborne polyurethanes.

Toughness Properties of Concrete Modified with Water-Borne Polyurethane

2012 ◽  
Vol 238 ◽  
pp. 109-117
Author(s):  
Bei Ding ◽  
Xia Zhang ◽  
Dong Ling Zhou ◽  
Chan Wen Miao
Keyword(s):  
Mechanical Performance ◽  
Concrete Strength ◽  
Harmful Effect ◽  
Impact Resistance ◽  
Block Polymer ◽  
Influence Of Water ◽  
Energy Ratios ◽  
Chain Conformations ◽  
The Impact ◽  
Water Borne

A novel kind of block polymer with characteristics of rod-like chain conformations, water-borne polyurethane (PUA), was synthesized by incorporate polyacrylate (PA) into the PU chain to prepare an aqueous polyurethane-polyacrylate (PUA) hybrid emulsion with core-shell structure. The influence of water-borne PUA on workability and mechanical performance of concrete were investigated experimentally. PUA had minimal harmful effect on the compressive strength whereas the flexural strength was increased by 23.2% with dosage of 0.5% and 23.3% with dosage of 1.0%, respectively. The fracture energy ratios of concrete with a dosage of PUA less than 1% are greatly improved more than double with the decreasing of concrete strength less than 10%. The water-borne PUA also enhances the early plastic cracking resistance and the impact resistance of concrete. The impact energy consumption of samples with PUA increase nearly three times more than reference samples, also better than samples with PP fiber. And PUA can refine the crack from 2-4mm to 0.2-0.5mm of the main distribution, decreasing total area of crack greatly.

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