Polyurea Microcapsules With Modified Biopolymers for Agglomeration Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Polyurea microcapsules tend to form agglomerates in aqueous anionic surface active compositions over time, particularly in unstructured products like liquid laundry preparations.
Innovation Solution
Incorporation of chemically modified biopolymers such as starches and gum Arabic in the first aqueous phase, along with guanidine carbonate in the second phase, to form polyurea microcapsules that resist agglomeration, using specific di- and polyisocyanates and oil components to enhance stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional colloidal protection agents are used in polyurea microcapsule production, then capsule formation is achieved, but agglomeration occurs over time in aqueous anionic surfactant compositions
Solution Approach 1:
The patent changes the chemical parameters of the colloidal protection agents by using chemically modified biopolymers (such as carboxymethyl cellulose, hydrolyzed soy protein, or hydrolyzed gelatin) instead of conventional unmodified biopolymers. These modified biopolymers have altered chemical properties that prevent agglomeration while maintaining capsule stability in aqueous anionic surfactant compositions.
Solution Approach 2:
The patent employs composite shell structures consisting of multiple layers with different functions. The shell comprises an inner layer formed by interfacial polymerization and an outer layer formed by coacervation, creating a composite structure that provides both capsule formation and resistance against agglomeration in complex aqueous environments.
2Reliability
If high concentrations of anionic surfactants are used in liquid detergents, then cleaning effectiveness is improved, but capsule agglomeration increases
Solution Approach 1:
The chemically modified biopolymer colloidal protection agents act as intermediary substances between the polyurea microcapsules and the anionic surfactants. These intermediaries modify the interaction between capsules and surfactants, preventing direct agglomeration while allowing the surfactants to maintain their cleaning effectiveness at high concentrations.
3Reliability
If temperature aging is applied to approximate storage conditions, then real-world performance is tested, but agglomeration becomes more pronounced
Solution Approach 1:
The patent performs preliminary stabilization during the capsule formation process by incorporating chemically modified biopolymers and controlling the coacervation and interfacial polymerization steps. This preliminary action creates a stable capsule structure that resists subsequent agglomeration during temperature aging and storage, allowing accurate prediction of real-world performance.
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 modified polyurea microcapsules exhibit significantly reduced agglomeration tendencies, maintaining stability in liquid detergents and softeners, allowing high active loading up to 80 wt.-% and suitable for liquid surfactant systems.
Implementation Method 1
forming an inner shell by interfacial polymerization at the interface between the internal phase and the outer shell
Implementation Method 2
emulsifying the oil phase into the surfactant solution to form a fragrance emulsion
Data Source
AI summary
Suggested are polyurea microcapsules obtainable or obtained by reacting di- and/or polyisocyanates and guanidine carbonate in the presence of chemically modified biopolymer colloidal protection agents. The capsules can be loaded for example with fragrances and show high resistance against agglomeration in unstructured (viscosity 10-300 cps), anionic surfactant based liquid products.