Unlock instant, AI-driven research and patent intelligence for your innovation.

Method for chain re-extension of waterborne polyurethane

A technology of water-based polyurethane and chain extender, which is applied in the direction of color/spectral characteristic measurement, etc., can solve the problems of poor performance and low molecular weight of water-based polyurethane, and achieve the effects of low implementation cost, improved comprehensive performance, and improved molecular weight and performance

Active Publication Date: 2015-05-20
LANZHOU SCISKY AQUEOUS POLYMER MATERIAL CO LTD
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a method for further chain extension of water-based polyurethane in view of the low molecular weight and poor performance of the existing water-based polyurethane, which can effectively increase the molecular weight of water-based polyurethane products, and then improve the performance of water-based polyurethane products

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for chain re-extension of waterborne polyurethane
  • Method for chain re-extension of waterborne polyurethane

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0013] Example 1. A method for water-based polyurethane chain extension again, carried out according to the following steps:

[0014] 1) Determination of terminal amine group content of finished waterborne polyurethane:

[0015] First, butanediamine is used as a sample, and the content of the configuration is 1×10 －6 g / ml~1×10 －4 For a series of ethanol solutions of butanediamine with different concentrations within the g / ml range, add 0.01 to 0.5 parts of ninhydrin ethanol solutions with a ninhydrin content of 1% to the sample solution, and use acetic acid to adjust the pH value to 6-6.5, after heating for 30-50 minutes in a water bath at 90°C-100°C (the system shows blue-purple), use double-beam visible spectroscopy to measure the absorption at 400-700nm, and obtain the standard according to the absorption peak height and the content of the amine group in the known sample Operating curve diagram (see figure 1 ).

[0016] Then take 1 part of finished water-based polyuret...

Embodiment 2

[0019] Example 2. A method for water-based polyurethane chain extension again, carried out according to the following steps:

[0020] 1) Same as the first step 1) of Embodiment 1.

[0021] 2) Re-extension of water-based polyurethane: take 100 parts of finished water-based polyurethane, calculate the content of amine groups of 1.7 mmol according to the content of terminal amino groups of water-based polyurethane in the finished sample measured above, add 0.38 g of polyethylene glycol epoxy resin (molecular weight 450) (1.7mmol epoxy group) re-chain extender, stirred and reacted for 1 hour at room temperature, and a water-based polyurethane product with high molecular weight and performance was obtained, with a molecular weight of 2.0×10 5 g / mol, the tensile strength of the coating film increased by 15% compared with that before chain extension.

Embodiment 3

[0022] Example 3. A method for water-based polyurethane chain extension again, carried out according to the following steps:

[0023] 1) Same as the first step 1) of Embodiment 1.

[0024] 2) Re-extension of water-based polyurethane: take 100 parts of finished water-based polyurethane, calculate the content of amine groups as 1.7mmol based on the content of the terminal amine group of the water-based polyurethane in the finished sample measured above, add 0.18g of IPDI (1.62mmol of isocyanate) and then extend the chain agent, stirred and reacted for 2 hours at room temperature to obtain a water-based polyurethane product with high molecular weight and performance, and its molecular weight reaches 2.2×10 5 g / mol, the tensile strength of the coating film increased by 21% compared with that before chain extension.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
tensile strengthaaaaaaaaaa
Login to View More

Abstract

The invention discloses a method for chain re-extension of waterborne polyurethane. The method comprises the following steps: reacting amino samples of different known concentrations with the developer ninhydrin, measuring absorption of visible light in a range of 400 to 700 nm by reacted products and drafting a standard working curve chart according to the height of absorption peaks and known content of amino groups in the samples; then subjecting the developer ninhydrin and terminated amino groups of a finished waterborne polyurethane sample to a color development reaction, carrying out measurement of visible light absorption and comparing obtained data with the standard working curve chart so as to determine the content of the terminated amino groups in the finished waterborne polyurethane sample; and adding a chain extender with an amount calculated according to the content of the terminated amino groups in the finished waterborne polyurethane sample and carrying out a chain re-extension reaction so as to increase molecular weight of a waterborne polyurethane product, thereby improving performance of the waterborne polyurethane product. Through usage of the chain re-extension method provided by the invention, average molecular weight and comprehensive performance of the prepared waterborne polyurethane product are improved by one time and 20%, respectively, compared with waterborne polyurethane before chain re-extension.

Description

technical field [0001] The invention belongs to the technical field of polymer material water-based polyurethane preparation, in particular to a method for further chain extension of water-based polyurethane. Background technique [0002] Water-based polyurethane uses water as the dispersion medium. It is non-toxic, tasteless, non-flammable, and non-explosive. During use, only water volatilizes into the atmosphere, which does not pollute the environment and does not cause poisonous harm to construction personnel. Products prepared using water-based polyurethane are non-toxic and harmful. Substance remains. Since its appearance in the 1970s, the development of water-based polyurethane as a green polymer material has been valued by governments of various countries. It has developed very rapidly and its product performance has also been qualitatively improved. However, compared with its corresponding product solvent-based polyurethane, there is still a certain gap in performan...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C08G18/76C08G18/58C08G18/75C08G18/73G01N21/31
Inventor 王武生戴家兵李维虎
Owner LANZHOU SCISKY AQUEOUS POLYMER MATERIAL CO LTD