Lignin Polymer Blend Melt Extrusion
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Solution Overview
Problem
Lignin-based thermoplastics typically exhibit high viscosity and brittleness, making them unsuitable for melt extrusion and additive manufacturing due to their lack of melt stability and resistance to buckling during extrusion.
Innovation Solution
A lignin-containing solid polymer blend material is developed by combining lignin with an acrylonitrile-containing rubber component and a styrene-containing thermoplastic component, resulting in a homogeneous blend with reduced melt viscosity and resistance to buckling, allowing for effective melt extrusion and 3D printing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If lignin-based thermoplastics are used for melt extrusion, then renewable and sustainable material benefits are achieved, but high viscosity and lack of melt stability prevent acceptable extrusion performance
Solution Approach 1:
The patent creates a composite material system combining lignin with a thermoplastic matrix (polyethylene, polypropylene, or polystyrene) and a compatibilizer (maleated polyethylene, maleated polypropylene, or styrene-maleic anhydride copolymer). This composite structure allows the renewable lignin to be incorporated while the thermoplastic matrix provides the necessary melt flow properties for extrusion and additive manufacturing.
Solution Approach 2:
The patent introduces a compatibilizer as an intermediary substance between lignin and the thermoplastic matrix. This compatibilizer (containing maleic anhydride or carboxylic acid groups) mediates the interface between the hydrophilic lignin and hydrophobic thermoplastic, improving interfacial adhesion and melt stability, thereby enabling acceptable extrusion performance while maintaining high lignin content (30-70 wt%).
2Adaptability or versatility
If lignin content is increased to maximize renewable material usage, then sustainability improves, but viscosity increases and melt stability decreases
Solution Approach 1:
The compatibilizer acts as a mediator that stabilizes the melt composition even at high lignin contents (30-70 wt%). The maleic anhydride or carboxylic acid groups in the compatibilizer form interfacial bonds with lignin, preventing phase separation and maintaining consistent melt properties throughout the extrusion process, thereby enabling high renewable material content without sacrificing melt stability.
Solution Approach 2:
The patent modifies the chemical parameters of the system by introducing functional groups (maleic anhydride, carboxylic acid) that change the interfacial properties between lignin and thermoplastic. This parameter change enables the system to maintain stability across a wide range of lignin concentrations, allowing maximum renewable material usage while preserving acceptable melt behavior.
3Ease of manufacture
If temperature is increased to improve melt flow, then extrusion ability improves, but lignin becomes crosslinked, degrades, and chars
Solution Approach 1:
The patent changes the rheological parameters of the system by introducing the thermoplastic matrix and compatibilizer, which modify the melt viscosity and flow characteristics. This allows the blend to achieve acceptable melt flow at lower temperatures compared to pure lignin, thereby preventing thermal degradation and charring while maintaining extrusion capability.
Solution Approach 2:
The composite structure with thermoplastic matrix provides a protective environment for lignin during processing. The thermoplastic component has higher thermal stability and acts as a barrier, reducing direct thermal exposure to lignin and preventing crosslinking and charring at extrusion temperatures, thereby maintaining material integrity while enabling melt flow.
4Adaptability or versatility
If lignin blends are used for additive manufacturing, then sustainable 3D printing is achieved, but brittleness and buckling resistance are insufficient
Solution Approach 1:
The patent creates a composite where the thermoplastic matrix provides mechanical strength and ductility, while the compatibilizer ensures good interfacial adhesion between lignin and matrix. This composite structure prevents brittleness by allowing stress transfer across the interface, and the thermoplastic matrix provides buckling resistance, enabling successful additive manufacturing with sustainable lignin-based materials.
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 blend achieves reduced melt viscosities, improved mechanical properties, and enhanced resistance to buckling, enabling the use of lignin in various objects produced through methods like fused deposition modeling, with high lignin loadings up to 50 wt% or higher.
Implementation Method 1
melt blending the following components: (i) a lignin-acrylonitrile component containing a homogeneous blend of a lignin component and an acrylonitrile-containing rubber component; and (ii) a styrene-containing thermoplastic component that is non-elastomeric, to form a polymer blend in which components (i) and (ii) are homogeneously blended
Implementation Method 2
While a good shear-thinning behavior permits good printability of a solid polymer
Implementation Method 3
a lignin-acrylonitrile component containing a homogeneous blend of a lignin component and an acrylonitrile-containing rubber component; and (ii) a styrene-containing thermoplastic component that is non-elastomeric
Data Source
AI summary
A solid polymer blend material comprising: (i) a lignin-acrylonitrile component containing a homogeneous blend of a lignin component and an acrylonitrile-containing rubber component; and (ii) a styrene-containing thermoplastic component that is non-elastomeric; wherein components (i) and (ii) are homogeneously dispersed in the polymer blend material. Methods for producing the blend material are also described. Methods for producing objects made of the blend material by melt extrusion are also described, comprising: (a) melt blending components (i) and (ii) to form a polymer blend in which components (i) and (ii) are homogeneously blended, wherein the polymer blend exhibits a melt viscosity of no more than 2000 Pa·s at a shear rate of 100-1000 s−1 and when heated to a temperature of no more than 240° C.; and (b) forming an object made of said polymer blend material.