Blocky Ethylene Propylene Copolymers Without Chain Shuttling Agents
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Solution Overview
Problem
Existing methods for producing blocky copolymers of ethylene and propylene with high melting temperatures require the use of chain shuttling agents, which add complexity and cost, and do not achieve the desired properties without them.
Innovation Solution
The development of blocky copolymers with semicrystalline ethylene sequences and amorphous or low crystallinity propylene sequences using metallocene-based catalyst systems without a chain shuttling agent, resulting in higher melting temperatures than random or blocky copolymers with similar comonomer contents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If chain shuttling agents are used to produce blocky copolymers of ethylene and propylene, then the copolymers can achieve desired block structure and melting temperatures, but the process complexity and cost increase
Solution Approach 1:
The patent removes the chain shuttling agent from the polymerization system while maintaining the ability to produce blocky copolymers with high melting temperatures. This extraction of the problematic component eliminates process complexity and cost associated with chain shuttling agents while preserving the desired block structure through optimized metallocene catalyst selection and polymerization conditions
Solution Approach 2:
The patent changes key parameters including catalyst type (metallocene-based), activator selection (borate or alumoxane), and polymerization conditions to achieve blocky copolymer structure without chain shuttling agents. These parameter changes enable the system to produce copolymers with melting temperatures above 90°C while simplifying the overall process
2Stability of the object's composition
If chain shuttling agents are used to produce blocky copolymers, then block structure can be achieved, but manufacturing cost increases
Solution Approach 1:
The patent extracts and eliminates the chain shuttling agent from the system, replacing it with a simplified catalyst system using metallocene catalysts combined with borate or alumoxane activators. This removal maintains block structure formation while eliminating the cost associated with purchasing and processing chain shuttling agents
Solution Approach 2:
The patent employs conventional, readily available metallocene catalysts and activators that are more economical than chain shuttling agents. These catalyst systems achieve the desired block structure through their inherent catalytic properties rather than requiring expensive chain shuttling agents, thereby reducing manufacturing costs
3Adaptability or versatility
If random copolymers or blocky copolymers with chain shuttling agents are produced, then certain properties are achieved, but melting temperatures are lower compared to copolymers without chain shuttling agents
Solution Approach 1:
The patent optimizes polymerization parameters including catalyst selection (metallocene-based), activator type (borate or alumoxane), monomer feed ratios, and reaction conditions to produce copolymers with enhanced block structure. These parameter changes result in higher melting temperatures (above 90°C) while maintaining desired copolymer properties such as composition, molecular weight, and microstructure
Solution Approach 2:
The patent creates local variations in copolymer structure by controlling the distribution of ethylene and propylene units at the molecular level. Through optimized catalyst systems and polymerization conditions, the patent produces regions with high ethylene content (semicrystalline) and regions with propylene content (amorphous or low crystallinity), creating the block structure necessary for high melting temperatures while preserving overall copolymer versatility
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 approach achieves higher melting temperatures and improved solubility characteristics in solvents like xylene and ortho-dichlorobenzene, with melting temperatures at least 10-20°C higher than comparable copolymers prepared with chain shuttling agents, demonstrating enhanced thermal properties without the need for additional complexity or cost.
Implementation Method 1
The polymers are preferably prepared using metallocene-based catalyst systems
Implementation Method 2
blocky copolymers having semicrystalline ethylene sequences and amorphous or low crystallinity propylene sequences
Implementation Method 3
The polymers have higher melting temperatures than previously known random copolymers or blocky copolymers
Data Source
AI summary
Copolymers comprising ethylene and propylene and methods for producing such polymers are provided. The polymers are blocky copolymers having semicrystalline ethylene sequences and amorphous or low crystallinity propylene sequences. The polymers are preferably prepared using metallocene-based catalyst systems but without the use of a chain shuttling agent. The polymers may have higher melting temperatures than previously known random copolymers or blocky copolymers prepared with chain shuttling agents having similar comonomer contents. The polymers include both ethylene-rich and propylene-rich copolymers.