Biodegradable Polyester Waterproofing Polymer for Sunscreen
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Solution Overview
Problem
Current sunscreen formulations lack biodegradable, natural polymers that provide high static and water-resistant Sun Protection Factor (SPF) performance, especially in water-resistant SPF 30, 50, 70, or 100 ranges, while also being environmentally friendly and free from microplastics.
Innovation Solution
A bio-based, biodegradable waterproofing polymer is developed through a non-sequential reaction of polyglycerol, dimer acid, and fatty acid, with a specific molar ratio, which imparts high static and water-resistant SPF to water-in-oil sunscreen formulations, utilizing hydrogenated dimer acid and isostearic acid to enhance molecular weight and viscosity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If synthetic polymers (PVP/olefin copolymers, acrylate copolymers) are used to provide high SPF and WR SPF, then water-resistant performance is improved, but biodegradability deteriorates and microplastic pollution occurs
Solution Approach 1:
The patent changes the chemical composition parameters by using biodegradable polyesters with specific molecular weights (5,000-1,000,000 Da) and specific structures (hydrophilic and hydrophobic segments) to achieve both water resistance and biodegradability. The polyester is designed with controlled functionality (2-4) and molecular weight to balance performance and environmental compatibility.
Solution Approach 2:
The patent creates a composite polyester material combining hydrophilic and hydrophobic segments within the same molecule. This composite structure allows the polymer to interact with both water and oil phases, providing water-resistant performance while maintaining biodegradability through natural polyester chemistry.
2Object-generated harmful factors
If biodegradable polyesters are used to replace synthetic polymers, then environmental friendliness is improved, but WR SPF performance deteriorates
Solution Approach 1:
The patent optimizes polyester parameters including molecular weight (5,000-1,000,000 Da), functionality (2-4), and hydrophilic-hydrophobic balance to achieve WR SPF of 50 or more. The specific parameter ranges are selected to ensure both biodegradability and water-resistant sun protection performance.
Solution Approach 2:
The patent develops a composite polyester structure with both hydrophilic and hydrophobic segments that work synergistically to provide water resistance. The hydrophobic segments interact with UV actives and oil phases while hydrophilic segments provide water solubility and biodegradability, achieving high WR SPF without sacrificing environmental friendliness.
3Reliability
If polymer loading is increased to improve water resistance, then WR SPF is improved, but formulation complexity and cost increase
Solution Approach 1:
The patent changes the polymer parameters to achieve high water resistance at low loadings (0.1-5 wt%). By optimizing molecular weight and structure, the polyester provides effective water resistance at concentrations much lower than conventional polymers, simplifying formulation and reducing cost.
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 polymer achieves superior water-resistant SPF performance, exceeding industry standards, and is environmentally friendly, providing effective water resistance and UV protection without contributing to microplastic pollution.
Implementation Method 1
Sunscreens contain so-called active materials that either absorb or scatter UV light of specified wavelengths
Implementation Method 2
More biodegradable hydrophilic and hydrophobic polyesters have been developed as additives to cosmetics and some have been recommended for sunscreens
Data Source
AI summary
The present disclosure generally relates to a waterproofing polymer that is a reaction product of the following components: (i) at least one polyglycerol; (ii) at least one dimer acid; and (iii) at least one fatty acid having 8-30 carbon atoms, wherein (iii) and (i) are in a molar ratio of less than 2:1. The components are charged to a reaction vessel and subsequently reacted to produce a polyester polymer having excellent waterproofing properties. The polymers impart high static and water-resistant SPF to water-in-oil sunscreen formulations.