Olefin Acrylate Copolymerization via Acid Catalyst
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Solution Overview
Problem
Current methods for copolymerizing ethylenically unsaturated olefins with polar monomers like acrylates in aqueous media result in low molecular weight polymers with limited hydrophobicity and mechanical integrity, failing to achieve desirable properties such as moisture resistance, adhesion to low surface energy substrates, and barrier properties against solvents and oxygen.
Innovation Solution
A free-radical initiator/acid catalyst system using Lewis or Brönsted acids is employed to copolymerize ethylenically unsaturated olefins with acrylates in aqueous media, producing high molecular weight polymers with improved hydrophobicity and mechanical properties, including the direct incorporation of aliphatic olefins into the polymer backbone.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If free radical polymerization of olefins and polar monomers is performed in nonaqueous media using Brönsted or Lewis acids, then copolymerization occurs with alternating sequences, but the molecular weight remains low and water must be meticulously removed
Solution Approach 1:
The patent changes the medium parameter from nonaqueous to aqueous, enabling the use of water-compatible Brönsted or Lewis acids while maintaining copolymerization reliability. This parameter change allows molecular weight to increase significantly without requiring meticulous water removal, as the aqueous environment is compatible with the acid catalysts.
2Object-affected harmful factors
If ethylenically unsaturated olefins copolymerize with acrylates, then hydrophobicity increases, but copolymerization rate remains low
Solution Approach 1:
The Brönsted or Lewis acid acts as an intermediary that complexes with the polar acrylate monomer or repeating units, modifying its reactivity. This intermediary action enables olefins with higher hydrophobicity to copolymerize at practical rates by mediating the interaction between the nonpolar olefin and polar acrylate, overcoming the naturally low copolymerization rate.
3Object-affected harmful factors
If styrene is used to contribute hydrophobicity to acrylate polymer, then glass transition temperature increases, but soft-flexible film formation is prevented
Solution Approach 1:
Instead of using styrene which raises Tg throughout the polymer, the patent uses aliphatic olefins that provide localized hydrophobicity through their alkyl side chains while maintaining the backbone flexibility. This local quality approach allows hydrophobicity without the penalty of elevated glass transition temperature, enabling soft-flexible film formation.
4Strength
If high molecular weight polymers are produced in aqueous media, then mechanical integrity and barrier properties improve, but copolymerization of olefins with polar monomers becomes difficult
Solution Approach 1:
The Brönsted or Lewis acid serves as an intermediary that enables the copolymerization of olefins with polar monomers in aqueous media. By complexing with the polar monomer or repeating units, it modifies reactivity to allow high molecular weight copolymer formation with mechanical integrity and barrier properties, making the manufacture of such copolymers feasible in aqueous environments.
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 copolymers exhibit enhanced glass transition temperature variability, improved barrier properties, and hydrophobicity, achieving desired properties like moisture resistance, adhesion to low surface energy substrates, and resistance to solvents and oxygen, while maintaining low cost and versatility.
Implementation Method 1
The copolymerization rates of such polar acrylates and nonpolar olefin monomers are modified, by the use of a Brönsted or Lewis acid that is believed to complex either the polar monomer or the repeating unit from the polar monomer when it is the free radical chain end.
Implementation Method 2
The free radical polymerization of olefins and polar monomers such as acrylates in nonaqueous media using Brönsted or Lewis acids as catalysts is well known.
Implementation Method 3
The resulting copolymer is a stable emulsion or dispersion of polymer particles in aqueous media.
Data Source
AI summary
A polymerization process to copolymerize hydrophobic ethylenically unsaturated C4-C30. J olefins with polar monomers such as acrylates is described. The process utilizes an acid source to modify/catalyze the reactivity of the polar monomer and/or radically activated repeat unit from the polar monomer to promote incorporation of the ethylenically unsaturated olefin. The copolymer shows excellent adhesion to a variety of polymeric and/or polar substrates such as polyolefins, acrylate coatings, wood, etc.