Sichuan University

Wei Lin

Jianhui Wu

Chunhua Wang

To Ngai

Long Zhang

Yifeng Sheng

Ngai To

The disclosure provides a new method for preparing a WPU synthetic leather foaming layer based on a Pickering foam template method. The key of the method is to use the soft waterborne polyurethane as raw materials, add waterborne crosslinking agent and hydrophobic inorganic solid particles as Pickering waterborne foam stabilizers to obtain Pickering waterborne foam slurry of polyurethane latex particles through high-speed emulsification; and dry the slurry to obtain the waterborne polyurethane foam layer. The preparation process does not use any organic solvents, is clean and environmentally-friendly, and is simple to operate, making it easier to realize industrialized production. In addition, the Pickering foam has strong interface stability, which effectively solves the problem of difficult adjustment of the pore size caused by the accumulation and collapse of bubbles during the drying process of the mechanical foaming method, and the prepared synthetic leather foam layer has good hygienic properties.

Method for preparing WPU synthetic leather foaming layers based on pickering foam template method

A method for preparing a novel waterborne polyurethane foam layer for synthetic leather is disclosed. The method includes first preparing a charged cellulose nanofiber by using a wood pulp as a raw material; meanwhile, subjecting a polyisocyanate, a macromolecular diol, a hydrophilic chain extender and a small molecular chain extender to a polyaddition reaction and an acid-base neutralization reaction in sequence, to obtain a cationic or anionic waterborne polyurethane; adding the charged cellulose nanofiber and a certain amount of a crosslinking agent to the oppositely charged ionic waterborne polyurethane emulsion, stirring the resulting mixture, forming a bimolecular layer at the gas/liquid interface by a self-assembly of the cellulose nanofiber and waterborne polyurethane nanoparticles through electrostatic interactions to obtain a stable Pickering foam; using the stable Pickering foam as a template, drying and solidifying to obtain the waterborne polyurethane foam layer for synthetic leather.

Method for preparing novel waterborne polyurethane foam layer for synthetic leather

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Chengdu, China

Wei Lin