Biodegradable Polyurea Microcapsules for Stable Active Release
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing microencapsulation technologies face challenges in achieving a balance between stability and biodegradability, as highly stable microcapsules often have poor biodegradability and vice versa, leading to issues with microplastic pollution and inefficient active ingredient release.
Innovation Solution
A method for producing biodegradable polyurea/polyurethane microcapsules using amino acids and a release agent, which involves a multi-step polymerization and crosslinking process to create a capsule shell with reduced polymer content, ensuring high stability and efficient active ingredient release while facilitating biodegradability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polyurea/polyurethane microcapsules are produced with high polymer content to ensure stability, then stability is improved, but biodegradability deteriorates
Solution Approach 1:
The patent changes the chemical composition parameters of the capsule wall by incorporating biodegradable polymers (polycaprolactone, polyglycolic acid, poly(lactic-co-glycolic acid)) instead of conventional non-biodegradable polyurea/polyurethane materials. This parameter change maintains encapsulation stability while enabling biodegradation, directly resolving the contradiction between stability and environmental harm.
Solution Approach 2:
The patent creates composite capsule wall materials by combining biodegradable polymers with crosslinking agents (epoxies, isocyanates, carbodiimides). This composite approach provides both the structural stability needed for effective microcapsules and the biodegradability required to eliminate microplastic pollution, simultaneously addressing both contradictory requirements.
2Reliability
If the capsule wall is made highly stable to prevent premature release, then stability is improved, but active ingredient release efficiency deteriorates
Solution Approach 1:
The patent creates a dynamic capsule wall system where crosslinking density and polymer composition can be adjusted to balance stability and release. The semi-interpenetrating network structure allows the wall to maintain integrity during storage then dynamically respond to environmental triggers (pH, temperature, enzymes) for controlled release, resolving the static contradiction between stability and release efficiency.
Solution Approach 2:
The patent applies different polymer compositions and crosslinking densities to different regions or aspects of the capsule wall. The wall provides high stability in regions where protection is needed while incorporating localized pathways or more labile bonds where controlled release should occur, allowing simultaneous optimization of both stability and release efficiency.
3Object-generated harmful factors
If natural shell materials are used to improve biodegradability, then biodegradability is improved, but manufacturing precision and stability deteriorate
Solution Approach 1:
The patent selects biodegradable polymers that serve multiple functions simultaneously: polycaprolactone and other biodegradable polymers provide both the required biodegradability and sufficient mechanical stability for capsule formation. The crosslinking agents further enhance structural integrity while maintaining biodegradability pathways, making the material universally suitable for both manufacturing and environmental degradation requirements.
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 method results in microcapsules with enhanced stability and targeted release of active ingredients while being predominantly biodegradable, reducing environmental microplastic impact and improving performance in consumer products.
Implementation Method 1
a first polymerization and/or crosslinking step, comprising: (a1) Providing an internal non-aqueous phase comprising at least one polyisocyanate having two or more isocyanate groups
Implementation Method 2
carrying out a second polymerization and/or crosslinking step by adding at least one hydroxyl group donor
Implementation Method 3
The contents of microcapsules can be released in various ways and are based in particular on one of the mechanisms described below: mechanical destruction of the capsule by crushing or shearing; destruction of the capsule by melting of the wall material, destruction of the capsules by dissolution of the wall material or diffusion of the active ingredients through the capsule wall
Implementation Method 4
diffusion of the active ingredients through the capsule wall
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a method for producing biodegradable polyurea/polyurethane microcapsules, preferably perfume-containing polyurea/polyurethane microcapsules, with improved biodegradability relative to microcapsules in the prior art. The invention also relates to biodegradable polyurea/polyurethane microcapsules, comprising at least one lipophilic active substance, which can be produced with the method according to the invention. In another embodiment, the invention relates to the use of this type of microcapsules or microcapsule-dispersions, comprising the microcapsules according to the invention, to produce household products, textile care products, detergents, fabric softeners, cleaning agents, scent boosters, scent lotions or fragrance intensifiers, cosmetics, body care products, agricultural products, pharmaceutical products, or printed coatings for paper. The invention also relates to consumer products comprising this type of microcapsules or microcapsule dispersions.