Brominated Block Copolymer Flame Retardant Miscibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current brominated vinylaromatic/diene block copolymers used as flame retardants in thermoplastic polymers, such as polystyrene foams, suffer from inadequate miscibility with vinylaromatic matrices, leading to reduced foam cell size and insulation effectiveness, and require complex and economically unfavorable production processes.
Innovation Solution
Development of brominated vinylaromatic-diene block copolymers with specific molar mass ratios and structures, including linear and star-shaped configurations, that exhibit improved miscibility and thermal stability, allowing for larger foam cells and efficient flame retardancy, produced through a simplified industrial process involving sequential anionic polymerization and controlled bromination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional brominated vinylaromatic/diene block copolymers are used as flame retardants, then flame retardancy is achieved, but miscibility with vinylaromatic matrices is inadequate leading to reduced foam cell size
Solution Approach 1:
The patent changes the molar mass parameters of the block copolymer components. Specifically, it uses a vinylaromatic polymer block with Mw ≥ 100,000 g/mol and a diene polymer block with Mw from 50,000 to 130,000 g/mol. This parameter optimization improves miscibility with the vinylaromatic matrix while maintaining flame retardancy, thereby preventing foam cell size reduction.
Solution Approach 2:
The patent creates a composite block copolymer structure combining vinylaromatic polymer blocks (polystyrene) and brominated diene polymer blocks (polybutadiene). This composite structure achieves both compatibility with the vinylaromatic matrix and flame retardancy, eliminating the need for separate flame retardant additives that would cause nucleation and reduced foam cell size.
2Reliability
If complex production processes are used for brominated block copolymers, then desired properties are achieved, but manufacturing cost and complexity increase
Solution Approach 1:
The patent performs preliminary bromination of the diene polymer block before combining it with the vinylaromatic polymer block. This preliminary action ensures that the brominated diene block has the required thermal stability and compatibility characteristics before final copolymer formation, simplifying the overall production process while maintaining product quality.
Solution Approach 2:
The patent segments the production process into distinct stages: (1) synthesis of vinylaromatic polymer block, (2) synthesis and bromination of diene polymer block, and (3) combination to form block copolymer. This segmentation allows each stage to be optimized independently, improving manufacturing efficiency while ensuring the final product meets required specifications.
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 new brominated block copolymers achieve homogeneous dispersion in thermoplastic polymers, enhancing foam cell size and flame retardancy while simplifying production, making them suitable for industrial applications.
Implementation Method 1
The new brominated block copolymers achieve homogeneous dispersion in thermoplastic polymers, enhancing foam cell size and flame retardancy
Data Source
AI summary
Brominated vinylaromatic-diene block copolymers (Br-SBC) comprising a vinylaromatic polymer block S and a brominated diene polymer block BB, wherein before bromination the weight-average molar mass Mw of the block S is greater than or equal to Mw of the block BB, use thereof as flame retardants, and also polymer compositions comprising these for unfoamed and foamed thermoplastic polymers, for example EPS and XPS.