End-Group Functionalized Polydiene Rubber for Better Scorch and Extrusion
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Solution Overview
Problem
Polydiene rubbers modified with cyclic amines for improved tire properties suffer from reduced Mooney scorch times and extrusion defects, particularly when combined with carbon-based fillers.
Innovation Solution
Use a second functionalization agent, such as a cyclic carbonyl, in addition to a cyclic amine to modify polydiene rubbers, creating polymers with improved Mooney scorch times and extrusion properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polydiene rubbers are modified with cyclic amine as a first functionalization agent, then the polymer interacts better with fillers and compound properties improve, but Mooney scorch time is reduced and extrusion properties deteriorate
Solution Approach 1:
The patent changes the chemical parameters of the end groups by introducing a second functionalization agent (cyclic carbonyl) that reacts with the cyclic amine-modified polymer chains. This transforms the end group structure from simple cyclic amine to a more complex functionalized structure containing both amine and carbonyl groups, which alters the polymer's interaction characteristics with fillers and processing properties, thereby improving Mooney scorch time while maintaining compound performance
Solution Approach 2:
The patent creates a composite functionalization system where two different functionalization agents (cyclic amine and cyclic carbonyl) work together on the polymer chains. The cyclic amine provides initial filler interaction capability, while the cyclic carbonyl adds complementary functionality that modifies the overall end group behavior, creating a synergistic effect that improves both compound properties and processing characteristics
2Reliability
If polydiene rubbers are modified with cyclic amine as a first functionalization agent, then the polymer interacts better with fillers and compound properties improve, but extrusion properties deteriorate with surface defects
Solution Approach 1:
The patent modifies the end group chemical structure by adding cyclic carbonyl functionality to the cyclic amine-modified polymer. This structural change alters the polymer's surface characteristics and interaction with processing equipment, reducing surface defects during extrusion while preserving the filler interaction capabilities provided by the cyclic amine groups
Solution Approach 2:
The cyclic carbonyl group acts as an intermediary modification that mediates between the cyclic amine's strong filler interaction and the polymer's processing behavior. It provides a chemical bridge that maintains the beneficial filler-polymer interaction while introducing steric and electronic effects that improve extrusion performance and reduce surface defects
3Loss of energy
If functional groups are introduced to improve filler interaction and reduce energy dissipation, then compound properties improve, but processing time window is reduced
Solution Approach 1:
The patent optimizes the functional group parameters by introducing cyclic carbonyl groups that modify the thermal and rheological behavior of the polymer. This changes the temperature-time profile of the polymer's processing characteristics, extending the viable processing time window while maintaining the energy dissipation reduction benefits from the filler-polymer interaction
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 resulting polymers exhibit enhanced Mooney scorch times and extrusion properties, leading to improved compound properties for tire production.
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
AI summary
An end-group functionalized polymer having one or more end groups according to the general formula (I)whereinR1 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 whereinR7 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.