Modified High Cis Polydiene for Filler Interaction and Cold Flow Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High cis polydiene polymers modified to enhance filler-polymer interactions for tire rubber compositions face challenges such as increased cold flow, which complicates storage and affects performance.
Innovation Solution
A modified high cis polydiene polymer is developed using a lanthanide-based catalyst system, functionalizing compounds, and silicon halides to achieve a high cis 1,4-bond content and desired Mooney viscosity, integrated into tire rubber compositions with specific filler and diene monomer contents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If high cis polydiene polymers are modified by functionalizing compounds to increase filler-polymer interactions, then filler-polymer interaction is improved, but cold flow increases causing storage challenges
Solution Approach 1:
The patent uses a specific functionalizing compound (formula I or II) as an intermediary between the polymer and filler. This compound contains a carbonyl group that can interact with filler surfaces while the rest of the molecule maintains polymer compatibility, thus improving filler-polymer interaction without excessively increasing cold flow
Solution Approach 2:
The patent optimizes the molecular structure parameters of the functionalizing compound, specifically the ratio of components in formula I or II, to achieve the right balance between filler interaction and cold flow. By adjusting these chemical parameters, the patent resolves the contradiction between improved interaction and excessive cold flow
2Strength
If functionalizing compounds are used to modify high cis polydiene polymers, then filler-polymer interaction increases, but Mooney viscosity becomes difficult to control
Solution Approach 1:
The patent precisely controls the molecular weight, functional group concentration, and structural parameters of the functionalizing compound to maintain Mooney viscosity within the desired range of 45-80 while still achieving improved filler interaction. This parameter optimization resolves the contradiction between enhanced interaction and viscosity control
3Strength
If polymer chains are end-functionalized to improve filler interaction, then filler-polymer interaction is enhanced, but polymer storage stability decreases
Solution Approach 1:
The functionalizing compound acts as a mediator that provides just enough polarity and reactivity for filler interaction while maintaining overall polymer stability during storage. The specific chemical structure (formula I or II) balances reactivity for filler bonding with stability for storage
Solution Approach 2:
The patent applies functionalization only at the polymer chain ends rather than throughout the entire polymer structure. This localized modification provides filler interaction capability where needed while preserving the bulk polymer's storage stability
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 modified polymer composition improves tire rubber properties by maintaining desired viscosity and reducing cold flow issues, enhancing storage stability and performance in tire components like treads.
Implementation Method 1
using the catalyst system of (a) to polymerize a quantity of conjugated diene monomer to produce polymer chains with a living end
Implementation Method 2
reacting the living end polymer chains from (b) with a functionalizing compound selected from formula I or formula II, thereby producing an intermediary product including polymer chains end functionalized with a residue from the first functionalizing compound
Implementation Method 3
coupling the intermediary product from (c) using a coupling agent selected from the group consisting of silicon halides, thereby producing a modified high cis polydiene polymer
Data Source
AI summary
Disclosed herein are a modified high cis polydiene polymer, processes for preparing the modified high cis polydiene polymer, and tire rubber compositions containing the modified high cis polydiene polymer. The processes make use of a functionalizing compound of formula I or formula II and a coupling agent to prepare the modified high cis polydiene polymer from a quantity of conjugated diene monomer polymerized using a lanthanide-based catalyst system. The modified high cis polydiene polymer includes at least one polymer chain having a residue from the functionalizing compound and a residue from the coupling agent and can be utilized in tire rubber compositions in combination with other ingredients such as fillers.