Diene Polymer Viscosity Control via Post-Polymerization Modification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current processes for producing diene polymers, such as high cis polybutadiene, face issues with side reactions, high polymer solution viscosities, and inadequate processing behaviors, leading to inferior polymer properties and increased energy consumption.
Innovation Solution
A process involving the polymerization of diene monomers with a catalyst composition containing rare earth elements and activators, followed by the addition of alkoxysilane compounds and thio compounds, which reduces solution viscosities and improves processing characteristics without compromising hysteresis and wear properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional Ziegler-Natta catalysts are used for polymerizing diene monomers, then polydienes with high cis-1,4-polybutadiene content can be produced, but side reactions occur and processing behavior is impaired due to high polymer solution viscosities
Solution Approach 1:
The patent introduces a post-polymerization modification step where organometallic compounds (such as aluminum alkyls) are added to the polymer solution to change the molecular structure parameters of the polymer. This creates controlled branching that reduces solution viscosity and improves processing behavior while maintaining the high cis-1,4-polybutadiene content achieved during polymerization
2Productivity
If polymer concentration in solution is increased to improve productivity, then production throughput increases, but polymer solution viscosity becomes excessively high impairing processing
Solution Approach 1:
The organometallic modification changes the rheological parameters of the polymer by introducing branching structures. This allows the polymer to be processed at higher concentrations without experiencing excessive viscosity buildup, thereby enabling increased productivity while maintaining good processing behavior
3Manufacturing precision
If temperature control and special catalyst components are used to address processing issues, then polymer properties may be improved, but energy consumption during manufacture increases
Solution Approach 1:
The patent replaces thermal processing methods (temperature control) with a chemical modification approach using organometallic compounds. This substitution allows processing improvement through molecular structure modification rather than energy-intensive heating or cooling, thereby reducing energy consumption while maintaining or improving polymer properties
4Reliability
If linear high molecular weight diene polymers are produced to achieve good hysteresis properties, then rolling resistance and wet grip improve, but solution viscosity increases and mixing with fillers becomes difficult
Solution Approach 1:
The organometallic modification introduces controlled branching into the linear polymer chains, changing the molecular architecture parameters. This branching reduces entanglement and solution viscosity, making the high molecular weight polymer easier to mix with fillers while preserving the linear chain characteristics that provide good hysteresis properties in the cured rubber
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 process results in diene polymers with reduced solution viscosities, improved processing behaviors, and enhanced production throughput, maintaining desirable properties like Mooney viscosities when mixed with fillers, thus facilitating better polymer-filler incorporation and product performance.
Implementation Method 1
polymerizing one or more diene monomers in the presence of a catalyst composition to give a reaction mixture
Implementation Method 2
the addition of one or more alkoxysilane compounds and the subsequent addition of at least one thio compound
Data Source
AI summary
The invention describes a process for producing a diene polymer, the process including the following steps in this order i) polymerizing one or more diene monomers in the presence of a catalyst composition to give a reaction mixture; ii) adding to the reaction mixture one or more alkoxysilane compounds; iii) adding S2Cl2, SCl2, SOCl2, S2Br2, SOBr2 or a mixture thereof to the reaction mixture; and iv) optionally adding a protic agent to the reaction mixture so as to deactivate the catalyst. The invention further includes polymers that are obtainable according to this process, as well as products including the polymer.