scholarly journals Effect of resins on the salt spray resistance and wet adhesion of two component waterborne polyurethane coating

e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 444-452 ◽  
Author(s):  
Qianwei Xu ◽  
Qingli Lu ◽  
Steven Zhu ◽  
Robin Pang ◽  
Wanwen Shan
Keyword(s):  
Salt Spray ◽  
Waterborne Polyurethane ◽  
Ir Absorption ◽  
Polyurethane Coating ◽  
Crosslinking Degree ◽  
Wet Adhesion ◽  
Two Component ◽  
Ft Ir ◽  
Level 1 ◽  
The Relationship

AbstractEffects of the type, chemical structure and NCO/OH of resins on wet adhesion and salt spray resistance of two component waterborne polyurethane coating were studied in this paper. The content of functional groups in resins and films were analysed by areas of their FT-IR absorption peak to study the relationship with anticorrosive performance of coatings. Coatings based on resins with more -OH tend to have stronger wet adhesion and salt spray resistance because resins with more -OH have more possibilities to react with -NCO to form a compact film with a higher crosslinking degree. The wet adhesion of coatings after 8 h of immersion deteriorated from level 1 to level 5 with the increase of NCO/OH due to the decrease of -OH in coatings to link with substrates. And excess -NCO tend to react with H2O to generate CO2 to form cracked physical bubbles, which would weaken the wet adhesion.

scholarly journals Study of the Effect of PGDA Solvent on Film Formation and Curing Process of Two-Component Waterborne Polyurethane Coatings by FTIR Tracking

Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 461 ◽  
Author(s):  
Ruitao Wang ◽  
Chunxiang Li ◽  
Zhigang Liu ◽  
Zhongping Yao ◽  
Zhijiang Wang ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Film Formation ◽  
Waterborne Polyurethane ◽  
Hydroxyl Groups ◽  
Curing Process ◽  
Polyurethane Coating ◽  
Polyurethane Coatings ◽  
Rate Of Reaction ◽  
Two Component

Waterborne polyurethane coatings were prepared using polyhydroxyacrylate dispersion, polyisocyanate, and propylene glycol diacetate (PGDA). The rate of reaction between hydroxyl and NCO groups in film formation and curing processes was studied by FTIR. The influence of PGDA amount on film formation and curing was also studied. Results showed that PGDA content had a significant effect on the curing process. With less than 10% PGDA, the role of PGDA was more to assist diffusion of polyhydroxyacrylate and polyisocyanate resin droplets. This promoted the reaction between hydroxyl groups and NCO. With more than 10% PGDA, its effect as a solvent was more and it inhibited the reaction between hydroxyl and NCO groups. When the amount of PGDA was about 10%, the synergy between both the roles promoted the crosslinking and curing reactions. The extent of the curing reaction of NCO was more than 70% in 4 h, which was significantly higher, compared with that of about 30% without PGDA. The good applicability and appearance of the waterborne polyurethane coating prepared in this study were verified for the application to carbon fiber metro vehicles.

scholarly journals Self-Assembly of Amphiphilic Linear−Dendritic Carbosilane Block Surfactant for Waterborne Polyurethane Coating

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1318 ◽  
Author(s):  
Ruitao Wang ◽  
Chunxiang Li ◽  
Zhaohua Jiang ◽  
Zhijiang Wang
Keyword(s):  
Self Assembly ◽  
High Speed ◽  
Large Scale ◽  
Side Reaction ◽  
Waterborne Polyurethane ◽  
Technical Solution ◽  
Polyurethane Coating ◽  
Complete Replacement ◽  
Two Component ◽  
Undesirable Side Reaction

The traditional two-component waterborne polyurethane coating system cannot effectively inhibit the undesirable side reaction between polyisocyanate and water during curing hardening. It is difficult to avoid the microbubbles formed by this reaction during the film formation process, which severely degrades the appearance and decreases the performance of the film. Therefore, the addition of an amphiphilic Linear-Dendritic carbosilane Block Surfactant (LDBS) to the hardener can physically separate the polyisocyanate emulsion from water through self-assembly. The bubble-free film thickness (BFFT) of the two-component waterborne polyurethane coating in this study is approximately 1.5-fold greater than commercial waterborne polyurethane coatings in today’s coating industry. Fourier transform infrared spectroscopy (FT-IR) varied the effectiveness of LDBS for inhibition of the undesirable side reaction. The successful application of the waterborne polyurethane coating with LDBS on the 600 km/h high-speed maglev train provides a technical solution for large-scale industrialization of waterborne polyurethane coating and complete replacement of solvent polyurethane coating.

Polarized microbeam FT-IR analysis of single fibers

1996 ◽  
Vol 54 ◽  
pp. 206-207
Author(s):  
Liling Cho ◽  
David L. Wetzel
Keyword(s):  
Molecular Orientation ◽  
Transition Point ◽  
Polymer Fibers ◽  
Single Fiber ◽  
Wire Grid ◽  
Polyester Fibers ◽  
Ft Ir ◽  
Ir Analysis ◽  
The Relationship ◽  
Wire Grid Polarizer

Polarized infrared microscopy has been used for forensic purposes to differentiate among polymer fibers. Dichroism can be used to compare and discriminate between different polyester fibers, including those composed of polyethylene terephthalate that are frequently encountered during criminal casework. In the fiber manufacturering process, fibers are drawn to develop molecular orientation and crystallinity. Macromolecular chains are oriented with respect to the long axis of the fiber. It is desirable to determine the relationship between the molecular orientation and stretching properties. This is particularly useful on a single fiber basis. Polarized spectroscopic differences observed from a single fiber are proposed to reveal the extent of molecular orientation within that single fiber. In the work presented, we compared the dichroic ratio between unstretched and stretched polyester fibers, and the transition point between the two forms of the same fiber. These techniques were applied to different polyester fibers. A fiber stretching device was fabricated for use on the instrument (IRμs, Spectra-Tech) stage. Tension was applied with a micrometer screw until a “neck” was produced in the stretched fiber. Spectra were obtained from an area of 24×48 μm. A wire-grid polarizer was used between the source and the sample.

scholarly journals The optical shielding performances and mechanisms of green flame-retardant two-component matte films under various application conditions

RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12696-12702
Author(s):  
Xuan Yin ◽  
Yunjun Luo
Keyword(s):  
Flame Retardant ◽  
Waterborne Polyurethane ◽  
Two Component

Herein, we meticulously investigated the optical shielding performances and mechanisms of green flame-retardant two-component waterborne polyurethane matte films based on a previous study.

Synthesis and Characterization of Polyaniline Film

2011 ◽  
Vol 239-242 ◽  
pp. 1382-1385
Author(s):  
Na Xu ◽  
Xiao Dong Shen ◽  
Sheng Cui
Keyword(s):  
Ammonium Persulfate ◽  
Pani Film ◽  
Cyclic Voltammograms ◽  
Ultrasonic Dispersion ◽  
Switching Speed ◽  
Color Changes ◽  
Fast Switching ◽  
Ft Ir ◽  
The Relationship

The electrochromic PANI film was prepared by emulsion polymerization with dodecyl benzene sulphonic acid (DBSA) as dopant and ammonium persulfate (APS) as initiator. Ultrasonic dispersion was adopted in the polymerization. The electrochemical properties, the surface morphology and structure of the prepared PANI film was characterized by means of Fourier Transform infrared spectroscopy (FT-IR), cyclic voltammograms (CV) and field emission scanning electron microscope (FE-SEM), respectively. The relationship between the morphology and properties of PANI film was detailedly discussed. The PANI film exhibited an excellent electrochromism with reversible color changes form yellow to purple. The PANI film also had quite good reaction kinetics with fast switching speed, and the response time for oxidation and reduction were 65 ms and 66 ms, respectively.

scholarly journals New Approach to Quantitative Analysis of Two-Component Polymer Systems by Infrared Spectroscopy

1996 ◽  
Vol 50 (6) ◽  
pp. 774-780 ◽  
Author(s):  
K. C. Cole ◽  
Y. Thomas ◽  
E. Pellerin ◽  
M. M. Dumoulin ◽  
R. M. Paroli
Keyword(s):  
Infrared Spectroscopy ◽  
Quantitative Analysis ◽  
Weight Fraction ◽  
Polymer Systems ◽  
Near Ir ◽  
Miscible Blends ◽  
Two Component ◽  
New Treatment ◽  
Two Peaks ◽  
The Relationship

A new treatment is proposed for quantitative analysis of two-component polymer systems by infrared spectroscopy. Like much previous work, it is based on a ratio involving two peaks in the same spectrum. The relationship between such a ratio and the concentration of a given polymer is inherently nonlinear. It is shown that this nonlinearity can be well described by a simple equation derived from the laws of optical transmission. This equation has the form χ1 = m1 + m2 R/(1 + m3 R), where χ1 is the weight fraction of polymer 1, the mi are adjustable coefficients, and the ratio R is equal to Aa/( Aa + Ab). The quantities Aa and Ab are the absorbances (peak heights or areas) at two frequencies a and b of which the first is associated mainly with polymer 1 and the second with polymer 2. This equation has been applied to various peak combinations in spectra of miscible blends of poly(phenylene ether) with polystyrene (both mid-IR and near-IR data) and immiscible blends of polypropylene with polyethylene (mid-IR data). It is shown that the equation is valid in all cases, covering the full concentration range from 0 to 100% even when the peaks used for the analysis involve absorption by both polymers. It is therefore believed to be of broad general usefulness for the analysis of polymer blends and copolymers.

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