Bioplastic Composites Resolving Starch Polymer Compatibility

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current biodegradable materials based on starch are limited by their brittleness, water sensitivity, and inferior mechanical properties, which hinder their application in industrial fields due to the use of dispersive blends and lack of compatibility between starch and hydrophobic polymers, leading to unstable and non-sustainable production processes.

Innovation Solution

Thermomechanical processing of flours that include fibers and non-starch polysaccharides with hydrophobic polymers, stabilized with protective colloids, to create homogeneous or co-continuous bioplastic materials with improved mechanical and barrier properties, reducing water sensitivity and enhancing biodegradability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If starch is used as the base material for biodegradable materials, then biodegradability is improved, but mechanical strength and resilience deteriorate due to brittleness

Engineering Contradiction:
ImprovebiodegradabilityVSAvoidmechanical strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent creates composite materials by combining starch with hydrophobic polymers (such as polyvinylidene fluoride, polyvinyl fluoride, or their copolymers) to form a heterogeneous blend. This composite structure allows the starch component to provide biodegradability while the hydrophobic polymer component provides mechanical strength and resilience, thereby resolving the contradiction between biodegradability and mechanical strength.

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If starch is used in dried state or at low water contents, then handling stability is improved, but mouldability deteriorates due to hardness and brittleness

Engineering Contradiction:
Improvehandling stabilityVSAvoidmouldability
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent utilizes the temperature-dependent properties of starch. During processing, water is added to gelatinize the starch at elevated temperatures, transforming it from a hard, brittle state to a soft, mouldable state. After moulding, the water is removed through drying, returning the starch to a stable, handleable state. This parameter change (water content and temperature) resolves the contradiction between handling stability and mouldability.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If plasticizers like glycerol are added to enhance mouldability, then ease of manufacture is improved, but stability deteriorates due to migration and loss during storage

Engineering Contradiction:
ImprovemouldabilityVSAvoidstorage stability
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent introduces hydrophobic polymers as intermediary components that interact with both the starch and water. These polymers form a matrix that traps water and provides structural support during storage, replacing the need for small-molecule plasticizers like glycerol. The hydrophobic polymer acts as a mediator that maintains mouldability through its interaction with water while preventing water migration and loss, thereby resolving the contradiction between ease of manufacture and storage stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Strength

If starch is combined with hydrophobic polymers, then mechanical strength is improved, but compatibility deteriorates leading to dispersive blends

Engineering Contradiction:
Improvemechanical strengthVSAvoidblend compatibility
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The patent employs water as an intermediary substance that facilitates compatibility between starch and hydrophobic polymers. During processing, water gelatinizes the starch and creates a compatible matrix that allows both hydrophilic starch and hydrophobic polymer components to coexist homogeneously. The water acts as a mediator that temporarily bridges the incompatibility between the two polymer types during processing, and is subsequently removed to leave a stable, compatible blend with improved mechanical strength.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 approach results in bioplastics with enhanced mechanical strength, resilience, and reduced water sensitivity, achieving better biodegradability and sustainability by eliminating the need for starch extraction and minimizing waste and energy consumption, while offering a more economic and environmentally friendly alternative to traditional starch-based materials.

Implementation Method 1

water is added to the starch in defined proportions. As a result of adding water and thermomechanical treatments, the internal bonds are broken and the material becomes softer and mouldable

Methodology Applied
Scientific EffectGelatinization: Gel

Implementation Method 2

Thermomechanical processing of flours that include fibers and non-starch polysaccharides with hydrophobic polymers, stabilized with protective colloids, to create homogeneous or co-continuous bioplastic materials

Methodology Applied
Scientific EffectThermomechanical processing: Thermomechanical Effect

Data Source

PatentEP2432830B1bioplastics
Publication Date: 2013.07.10 WACKER CHEMIE AG
  • EP2432830B1 patent drawingFigure 1~2
  • EP2432830B1 patent drawingFigure 3~4

AI summary

In a first aspect, the invention thus pertains to thermoplastic processable compositions (base compositions) comprising one or more flours, one or more polymers, optionally plasticizers, optionally fillers and optionally additives, characterized in that at least one of the polymers is present in the form of its water-redispersible polymer powder or as aqueous polymer dispersion, whereby the compositions contain less than 12% by weight of polyvinyl alcohol, based on the total amount of polymeric components of the composition.