End-Functionalized Polydiene Rubber for Scorch-Stable Extrusion
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Solution Overview
Problem
Polydiene rubbers modified with cyclic amines exhibit reduced Mooney scorch times and extrusion properties when used with carbon-based fillers, leading to processing issues and surface defects in tire production.
Innovation Solution
A second functionalization agent, such as a cyclic carbonyl, is used in conjunction with a cyclic amine to improve the Mooney scorch times and extrusion properties of polydiene rubbers, resulting in improved polymer compounds for tire production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If polydiene rubbers are modified with cyclic amine as functionalization agent, then the polymer interacts better with filler surface and dispersion improves, but Mooney scorch time decreases and extrusion properties deteriorate
Solution Approach 1:
The patent introduces a second functionalization agent (cyclic carbonyl) as an intermediary that modifies the end groups introduced by the cyclic amine. This secondary modification adjusts the chemical properties of the end groups to reduce harmful interactions during processing while preserving the beneficial filler interaction capabilities. The cyclic carbonyl acts as a mediator between the cyclic amine end groups and the processing conditions, improving Mooney scorch time and extrusion properties.
2Ease of manufacture
If polydiene rubbers are modified with cyclic amine as functionalization agent, then the polymer interacts better with filler surface and dispersion improves, but surface defects increase during extrusion
Solution Approach 1:
The cyclic carbonyl compound serves as a secondary modifying agent that adjusts the chemical characteristics of the end groups. This intermediary modification reduces the tendency for surface defect formation during extrusion while maintaining the improved filler dispersion properties. The second functionalization agent mediates between the initial cyclic amine modification and the extrusion process, preventing surface defects.
3Ease of manufacture
If polydiene rubbers are modified with cyclic amine as functionalization agent, then the polymer interacts better with filler surface, but processing time window is reduced
Solution Approach 1:
The cyclic carbonyl compound acts as a time-mediated functionalization agent that extends the processing time window. By introducing this second functional group, the patent creates a more stable end group configuration that reduces premature vulcanization and extends the period during which the rubber can be processed at elevated temperatures, thus increasing the available processing time window.
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 combined use of two functionalization agents enhances the processing properties of polydiene rubbers, allowing for the production of articles with improved properties and reduced defects.
Implementation Method 1
adding a first functionalization agent of the general formula (II) to create a first functionalized polymer containing one or more end groups obtained by the reaction of the polymer chain end of the polydiene polymer with the functionalization agent of formula (II)
Implementation Method 2
adding a second functionalization agent to react with the first functionalized polymer and wherein to second functionalization agent is selected from the group of cyclic carbonyls
Data Source
Figure 1
AI summary
An end-group functionalized polymer having one or more end groups according to the general formula (I) wherein R1 represents a saturated or unsaturated, linear or branched, preferably aliphatic, hydrocarbon group having from 1 to 20 carbon atoms which, in addition to C and H, may contain one or more heteroatoms, preferably independently of one another selected from O, N, S or Si; R2, R3 are identical or different and represent saturated or unsaturated hydrocarbon groups having from 1 to 20 carbon atoms and wherein the hydrocarbon group may contain, in addition to C and H atoms, one or more heteroatoms, preferably selected from the group consisting of O, N, S and Si; A represents a residue selected from the group consisting of O-R4-OH, R5-OH and R6-NH- R7, preferably O-R4-OH wherein R4, R5 and R6 represent a saturated or unsaturated linear or branched hydrocarbon group which, in addition to C and H atoms, may contain one or more heteroatoms, independently selected from O, N, S or Si and which contains from 1 to 20 carbon atoms and wherein R7 represents H or a linear or branched or cyclic aliphatic or aromatic hydrocarbon group having from 1 to 20 carbon atoms and which, in addition to C and H atoms, may contain one or more heteroatoms, preferably selected from O, N, S or Si; and wherein the polymer is a homopolymer of a conjugated diene or a copolymer of at least one or more conjugated diene and one or more vinylaromatic monomer and, optionally one or more other comonomers. Also provided are a process for making the polymers and articles made with the polymers.