Dialcohol Cellulose Spherical Capsules for Biodegradable Thermal Expansion

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Solution Overview

Problem

Current thermally expandable microspheres are not derived from sustainable sources and are non-biodegradable, lacking a biologically sourced alternative for forming hollow, expandable spherical capsules with a core-shell structure suitable for applications like drug delivery.

Innovation Solution

Development of spherical capsules with a polymeric shell made from optionally substituted dialcohol cellulose, using a process involving a solution of dialcohol cellulose and non-polar organic compounds with an antisolvent to form hollow, expandable capsules with a core-shell structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If thermoplastic polymers are used in microspheres, then the microspheres can be thermally expanded, but the polymers are not derived from sustainable sources and are non-biodegradable

Engineering Contradiction:
Improvethermal expandabilityVSAvoidenvironmental sustainability
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the chemical composition parameters of the polymeric shell from conventional thermoplastic polymers to dialcohol cellulose and its derivatives, which are biodegradable and sustainable while maintaining the thermal expandability property through careful selection of polymer structure and blowing agent

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses composite material structures combining dialcohol cellulose with blowing agents (such as CO2 or organic carbonates) to create biodegradable expandable microspheres that combine the sustainability of natural polymers with the expandability function of thermoplastic systems

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If conventional cellulose spheres are made, then they are biologically sourced, but they are bead-like rather than hollow capsules and cannot be expanded once formed

Engineering Contradiction:
Improvebiological sourcingVSAvoidexpandability and hollow structure
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The invention segments the cellulose structure into dialcohol cellulose units that can form hollow capsule structures rather than solid beads, enabling the creation of a core-shell configuration with an expandable hollow interior

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the physical state parameters of the cellulose derivative from solid bead formation to hollow capsule formation by controlling the phase separation and solidification process during microencapsulation, enabling subsequent expansion capability

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If thermoplastic polymers are used, then the microspheres can be manufactured with controlled properties, but they pose cumulative build-up risk in the environment due to non-biodegradability

Engineering Contradiction:
Improvemanufacturing controlVSAvoidenvironmental persistence
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The invention changes the chemical composition parameters to use dialcohol cellulose with specific degree of substitution and molecular weight characteristics that enable both manufacturing control and biodegradability, replacing persistent thermoplastic polymers with environmentally benign alternatives

Inventive Principle:
Principle #35Parameter changes

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 solution provides biodegradable, expandable capsules with a core-shell structure, suitable for various applications including drug delivery and lightweight materials, utilizing environmentally friendly and sustainable cellulose-based materials.

Implementation Method 1

the blowing agent vapourises and expands, thus expanding the microsphere

Methodology Applied
Scientific EffectVapourisation: Evaporation

Implementation Method 2

the thermoplastic polymeric shell softens, and the blowing agent vapourises

Methodology Applied
Scientific EffectSoftening: Melting

Data Source

PatentEP3914384B1Dialcohol cellulose-based spherical capsules
Publication Date: 2024.12.11 AKZO NOBEL CHEMICALS INTERNATIONAL BV
  • EP3914384B1 patent drawingFigure 1(a)~2(b)
  • EP3914384B1 patent drawingFigure 3(a)~3(f)
  • EP3914384B1 patent drawingFigure 4(a)~5(b)

AI summary

The invention relates to spherical capsules comprising a polymeric shell surrounding a hollow core, in which the polymeric shell comprises an optionally substituted dialcohol cellulose. The invention also relates to a process for preparing such spherical capsules, comprising mixing a solution comprising dissolved optionally substituted dialcohol cellulose and one or more non-polar organic compounds with an antisolvent, wherein the antisolvent comprises or consists of one or more compounds, and has a polarity less than that of water.