Thermosensitive Light-Adjusting Material via Composite Polymer Phase Separation

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Solution Overview

Problem

Existing thermally light-scattering polymeric materials face challenges such as high water content, poor mechanical properties, and the use of harmful organic solvents, which limit their application and environmental sustainability.

Innovation Solution

A thermosensitive light-adjusting material is developed by photo- or thermo-polymerizing a polymer polyol and a hydroxyl-terminated polymer with a hydroxyl-containing carbon-carbon unsaturated monomer, eliminating the need for water and organic solvents, and featuring a high optical transmittance difference between transparent and cloudy states, achieved through a simple and efficient preparation process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If thermally light scattering polymeric materials are used for solar shading, then light-adjusting function is achieved, but mechanical properties deteriorate and water content increases

Engineering Contradiction:
Improvelight-adjusting functionVSAvoidmechanical properties
Core Design Contradiction:
Illumination intensityVSStrength

Solution Approach 1:

The patent uses a composite polymer system consisting of a thermally light scattering polymer matrix combined with a transparent polymer. This composite structure allows the material to maintain both the light-adjusting function (through phase separation and light scattering in the thermally responsive polymer) and good mechanical properties (through the reinforcing effect of the transparent polymer phase), resolving the contradiction between functional performance and mechanical strength.

Inventive Principle:
Principle #40Composite materials

2Illumination intensity

If traditional thermally light scattering materials are used, then light scattering effect is achieved, but harmful organic solvents are required

Engineering Contradiction:
Improvelight scattering effectVSAvoidorganic solvents
Core Design Contradiction:
Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the preparation parameters by using water as the solvent instead of harmful organic solvents. The thermally light scattering polymer and transparent polymer are dissolved or dispersed in water, and the material is formed through aqueous processing methods. This parameter change eliminates the use of harmful organic solvents while maintaining the light scattering effect through controlled phase separation during or after processing.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If high water content materials are used, then environmental sustainability is improved, but mechanical properties worsen

Engineering Contradiction:
Improveenvironmental sustainabilityVSAvoidmechanical properties
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent creates a composite material system where a water-based thermally light scattering polymer is combined with a transparent polymer matrix. The transparent polymer provides structural support and mechanical strength, while the thermally responsive polymer provides the light-adjusting function. This composite approach allows high water content (improving environmental sustainability) while maintaining good mechanical properties through the reinforcing transparent polymer phase.

Inventive Principle:
Principle #40Composite materials

4Illumination intensity

If thermally light scattering material is used for solar shading, then light intensity adjustment is achieved, but transmittance in transparent state may be insufficient

Engineering Contradiction:
Improvelight intensity adjustmentVSAvoidoptical transmittance
Core Design Contradiction:
Illumination intensityVSQuantity of substance

Solution Approach 1:

The patent applies local quality by creating distinct phases within the material: a transparent polymer phase that provides high optical transmittance when in the transparent state, and a thermally light scattering polymer phase that provides light scattering capability. The transparent polymer phase ensures sufficient light transmission (≥75%) in the transparent state, while the thermally responsive phase provides the light-adjusting function through temperature-dependent phase separation and light scattering.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The material exhibits strong light-adjusting properties, improved mechanical properties, and environmental sustainability, with a repeatable thermo-optic inter-phase swing, reducing manufacturing costs and environmental impact.

Implementation Method 1

above the transformation temperature (i.e. cloud point), some micro-phases, micro-crystalline or micro-areas with unmatched refractive indexes caused by a phase separation and a aggregation structure transformation, allow for an incident light scatting inside the material

Methodology Applied
Scientific EffectPhase separation:

Implementation Method 2

allow for an incident light scatting inside the material, showing a cloudy state

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 3

After the temperature is reduced below the cloud point, these micro-phases, micro-crystalline or micro-areas disappear gradually, and the system goes back to a homogeneous phase, showing a transparent state again

Methodology Applied
Scientific EffectHomogeneous phase transformation:

Data Source

PatentEP2186857B1A thermosensitive light-adjusting material and process thereof, and an optical device comprising thereof
Publication Date: 2018.04.11 CHENGDU BYSUN HI TECH MATERIALS
  • EP2186857B1 patent drawingFigure 1~2

AI summary

A thermosensitive light-adjusting material is formed by reacting 18-84% polymer polyols and/or terminal hydroxyl-containing polymers which are formed by reacting polymer polyols and diisocyanate, with 15-80% terminal hydroxy-containing ethylenically unsaturated monomers through light or heat polymerization reaction. A process for preparing the thermosensitive light-adjusting material and an optical device comprising thereof. The light-adjusting ability is high, the light-adjusting range is broad, and mechanical capability is good. The preparation method is simple, short-circle, and high effective, so it can be applied in industry, furthermore, because of no organic solvents, the method's advantages are low cost and without pollution.