Pd(II) Catalyst Composition for Controlled Olefin Polar Copolymerization
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Solution Overview
Problem
Existing catalysts and processes for olefin and polar vinyl monomer copolymerization require high temperatures and pressures, leading to randomly distributed polar monomers or accumulation at the ends of polymer chains, with limited control over molecular weight and structure.
Innovation Solution
A novel class of palladium-based catalysts with specific ligands, operating at low temperatures and pressures, allows for random or controlled distribution of polar monomers in the main chain or branches, with a content of less than 10% and molecular weights between 800-300,000 Dalton.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high temperatures and pressures are used in copolymerization, then the polymerization reaction proceeds efficiently, but the polar monomers become randomly distributed or accumulate at chain ends with limited molecular weight control
Solution Approach 1:
The patent changes the chemical parameters of the catalytic system by introducing a specific palladium complex with a diazabutadiene ligand and a weakly coordinating anion. This parameter change allows the reaction to proceed at lower temperatures and pressures while achieving precise control over polar monomer distribution and molecular weight, resolving the contradiction between reaction efficiency and structural control.
Solution Approach 2:
The patent employs a composite catalytic system comprising palladium, a diazabutadiene ligand with specific R1 and R2 substituents, and a weakly coordinating anion. This composite catalyst design enables simultaneous achievement of high activity and precise control over copolymer structure, allowing polar monomers to be distributed throughout the chain rather than accumulating at ends.
2Productivity
If high temperatures and pressures are used in copolymerization, then the polymerization reaction proceeds efficiently, but the molecular weight and structure of the produced macromolecules cannot be controlled
Solution Approach 1:
The patent modifies the catalytic system parameters by using a palladium complex with a specific diazabutadiene ligand structure and a weakly coordinating anion. This parameter modification enables the reaction to occur under milder conditions while achieving precise control over molecular weight (800-300,000 Dalton) and macromolecular structure, resolving the contradiction between productivity and precision.
3Quantity of substance
If polar monomer content is increased in copolymers, then the copolymer properties are enhanced, but the polar monomers accumulate at the ends of polymer chains
Solution Approach 1:
The patent changes the catalytic parameters by employing a palladium complex with a diazabutadiene ligand and a weakly coordinating anion. This parameter change enables the incorporation of polar monomers throughout the polymer chain rather than at chain ends, achieving both high polar monomer content and uniform distribution, thus resolving the contradiction between quantity and compositional stability.
Solution Approach 2:
The patent uses a composite catalyst system comprising palladium, a diazabutadiene ligand with specific substituents, and a weakly coordinating anion. This composite system enables precise control over monomer incorporation, allowing polar monomers to be distributed uniformly throughout the copolymer chain while maintaining high polar monomer content, thereby achieving both enhanced properties and compositional uniformity.
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
Achieves copolymers with controlled polar monomer distribution and high molecular weight, enabling a broader range of physico-chemical properties for new products.
Implementation Method 1
a catalyst for copolymerization of olefins and polar vinyl monomers and homopolymerization of olefins
Implementation Method 2
said catalyst having the general formula (I) wherein: palladium is in oxidation state +2; the dashed lines indicate coordination of palladium by the two nitrogen atoms
Data Source
AI summary
The invention relates to a family of Pd(II)-based catalysts of general formula (I) reproduced below for use in the production of olefin/polar vinyl monomer copolymers and olefin homopolymers. The invention also refers to ligands that are intermediates in the synthesis of the catalysts, to the process for the synthesis of homo- and copolymers using these catalysts, and to the homo- and copolymers thus obtained.