Preparation and characterization of one‐component polyurethane powder adhesives by the solution polymerization technology

Abstract

A new technology integrating the synthesis and granulation was adopted to prepare the one-component polyurethane powder adhesives (PPAs) by the solution polymerization. The influence of R total , neutralization, and types of dispersion solution on the properties of PPAs was investigated. It was found that the initial melting temperature increased and storage stability decreased with increasing R total . The neutralization reaction between the carboxylic group and amino group made the reduction of the sizing temperature and the increase of the T-peel adhesion strength. The granulation behaviors of the polyurethane (PU) prepolymer under different dispersion solutions showed that the PU prepolymer can be effectively blocked by the 20-30 wt % NaHSO 3 or n-butyl alcohol. Furthermore, the blocked polymers formed small particles with the ideal sizing temperature and peel strength. The excellent adhesive property and thermal stability of PPAs could meet the requirements of the industrial gluing in the fields of packaging, lining, and footwear.

Self‐healing supramolecular waterborne polyurethane dispersions with quadruple hydrogen bonds in main chain

“…As Figure 2 shows, the absence of characteristic peak of NCO groups at 2270 cm −1 in all spectrums means the polymerization reaction completely done. [34] The broad In addition, as the partial enlarged view shows, three absorption characteristic peaks at 1661, 1636, and 1587 cm −1 can be ascribed to the signals of CO stretching in ureido, CO stretching in amide, and CC stretching in the UPy dimers, respectively. Obviously, the spectra of HMA in the same region prove that these three peaks correspond to UPy units.…”

Strengthening the mechanical properties of polysulfide adhesives by introducing polyurethane

“…18 Polyurethane has drawn widespread attention to the highperformance modification of adhesives due to specific two-phase chemical structures and designable segments. 19,20 More importantly, the unique moisture curing of polyurethane can fundamentally overcome the shortcomings of uneven dispersion from metal curing agents. Recently, many researchers have focused on obtaining various properties of adhesives, such as solvent resistance, 21,22 self-healable, 23 and mechanical properties 24 by the reaction of highly reactive sulfhydryl groups with diisocyanate.…”

“…Embedding the poly‐functional polymers with epoxy resin structure into the polysulfide network can effectively strengthen their mechanical properties, but the fact that epoxy‐polysulfide copolymers still suffer from curing problems with the uneven dispersion of the metal peroxide powders 18 . Polyurethane has drawn widespread attention to the high‐performance modification of adhesives due to specific two‐phase chemical structures and designable segments 19,20 . More importantly, the unique moisture curing of polyurethane can fundamentally overcome the shortcomings of uneven dispersion from metal curing agents.…”

Curing Kinetics of Methylene Diphenyl Diisocyanate—Based Polyurethane Elastomers

“…Depending on its chemical structure and preparation process, PU can be used as elastomer, adhesive, coating, etc. [2][3][4]. PU contains carbamate group (-NH-COO-) in its molecular structure, which is generally obtained by the reaction of isocyanate and polyol.…”