Self-curing behaviors of single pack aqueous-based polyurethane system

Abstract

A di-or triaziridinyl compound served as the latent curing agent for the prepared carboxylic groups containing aqueous-based polyurethane (PU) dispersions. It was formulated as a single pack self-curable aqueous-based PU system. This system was stable under an alkaline environment and its curing reaction could be initiated by a pH control. A model reaction between a monoaziridinyl compound and formic acid was demonstrated and identified by infrared spectrophotometry. The stabilities of this convenient one-package PU system with a different dosage of di-or triaziridinyl latent curing agent were monitored by a particle sizer and fluorescence spectroscopy. The PU films were cast and self-cured from these single pack PU dispersions at ambient temperature. The physical and mechanical properties as well as thermal behaviors of each self-cured PU were evaluated.

Micromorphology and phase behavior of cationic polyurethane segmented copolymer modified with hydroxysilane

“…Waterborne polyurethane (WPU) dispersions, due to their superior properties and environmental advantages, have gained great attention in many commercial fields, such as coatings and adhesives for various substrates [1][2][3][4][5][6][7][8][9][10]. However, some properties of WPU still need to be improved further, such as water resistance and thermal stability, etc.…”

The influence of the ionic concentration, concentration of the polymer, degree of neutralization and chain extension on aqueous polyurethane dispersions prepared by the acetone process

“…To reduce or eliminate organic solvents from the formulations, solvents should be partially or completely replaced with environmentally benign solvents (e.g. water), in the coating formulations to achieve little or no VOC content [5][6][7][8][9][10][11][12][13].…”

Performance properties of self-curing aqueous-based PU system with tri-glycidyl phosphate curing agent

“…The property improvements of aqueous-based PU are modified by post-curing reaction [6][7][8][9][10][11][12][13][14][15][16][17][18][19]24] or polymer hybridization process [20][21][22][23] to enhance its cross-linking density, average molecular weight and further for performance properties. Therefore, a curing agent is a key component for improving aqueous PU performance properties.…”

“…There were several types curing agent, such as, multifunctional aziridine [7][8][9][10][11][12][13][14][15][18][19][20][21][22][23] and azetidine [16,17,24] have been reacting toward PU carboxylic acid and forming Scheme 1 Preparation of amino-terminated anionic aqueous-based PU dispersions amino-ester bonds among aqueous-based PU molecules. The final cured PU properties improvement proved that these are effective post-curing agents for carboxylic ion containing PU system, respectively.…”