Melt Polymerization of Random-Structure Poly(Ethylene-Vinyl Acetate)

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Solution Overview

Problem

Existing methods for producing ethylene-vinyl acetate copolymers involve emulsion polymerization with stepwise feeding and result in isotactic structures with specific vinyl acetate unit sequences along the ethylene chain, requiring multiple reagents and high energy consumption.

Innovation Solution

A five-step method involving melt addition polymerization of polyethylene and vinyl acetate using sodium persulfate as an initiator, with recirculation of reaction vapors through absorption-diffusion and condensation zones to achieve a non-specific spatial configuration of vinyl acetate units, minimizing reagents and energy use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If emulsion polymerization with stepwise feeding is used, then poly(ethylene-vinyl acetate) copolymer can be produced, but the process requires multiple reagents and high energy consumption

Engineering Contradiction:

Improvereagent consumptionVSAvoidprocess complexity

Core Design Contradiction:

Quantity of substanceVSEase of manufacture

Solution Approach 1:

The patent extracts and eliminates unnecessary reagents from the polymerization process by using a simplified system with only essential components (ethylene, vinyl acetate, and a single initiator), replacing the complex multi-reagent emulsion system with a cleaner, more efficient process that reduces chemical waste and costs

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the polymerization parameters by conducting the reaction in a bulk melt state rather than emulsion, operating at elevated temperatures (150-250°C) and pressures (100-300 atm), which simplifies the reagent requirements and reduces the need for multiple chemical additives while maintaining productive copolymer formation

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If emulsion polymerization with stepwise feeding is used, then poly(ethylene-vinyl acetate) copolymer can be produced, but high energy consumption is required

Engineering Contradiction:

Improveenergy consumptionVSAvoidproduction efficiency

Core Design Contradiction:

Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent implements continuous polymerization where ethylene and vinyl acetate are fed continuously in proportional amounts throughout the reaction process, eliminating the energy-intensive stepwise feeding operations and maintaining steady-state reaction conditions that improve energy efficiency while sustaining high productivity

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The patent optimizes energy consumption by adjusting the temperature and pressure parameters to optimal ranges (150-250°C, 100-300 atm) where the polymerization reaction proceeds most efficiently, reducing the energy input required per unit of polymer produced while maintaining high production rates

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If classic emulsion polymerization is used, then isotactic structure with specific vinyl acetate unit sequence is obtained, but the process is complex and reagent-intensive

Engineering Contradiction:

Improvespatial configuration controlVSAvoidprocess complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent inverts the approach by not attempting to control specific isotactic sequences through complex emulsion processes, but rather accepting and utilizing the random spatial configuration that naturally arises in bulk polymerization, thereby simplifying the process while producing copolymer with non-specific but commercially valuable random structure

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent extracts the unwanted complexity of controlling specific tacticity from the process, removing the need for sophisticated emulsion systems and multiple reagents, and focuses instead on the essential polymerization function to produce copolymer with random configuration that meets commercial requirements

Inventive Principle:

Principle #2Taking out (Extraction)

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

Produces poly(ethylene-vinyl acetate) copolymers with random vinyl acetate distribution, reducing energy consumption, reagent use, and eliminating destructive structures, while allowing for secondary polyethylene regeneration.

Implementation Method 1

melt addition polymerization of primary or secondary polyethylene (LDPE or HDPE) and vinyl acetate (VAM) occurs in the presence of sodium persulphate as initiator of the copolymerization process

Methodology Applied

Scientific EffectAddition polymerization: Chemical Bonding

Implementation Method 2

recirculation of reaction vapors through absorption-diffusion and condensation zones

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 3

recirculation of reaction vapors through absorption-diffusion and condensation zones

Methodology Applied

Scientific EffectCondensation: Condensation

Data Source

PatentUS20250333556A1Poly (ethylene-vinyl acetate) copolymer with non-specific spatial configuration, method for its preparation and use

Publication Date: 2025.10.30 KEMIKAL INOVEYSHAN EOOD

AI summary

A new poly (ethylene-vinyl acetate) copolymer with a non-specific spatial configuration of the vinyl acetate units with respect to the main ethylene chain. Also, a method for its production through addition polymerization of polyethylene and vinyl acetate and to its use. The new poly (ethylene-vinyl acetate) copolymer will find application in various branches of the chemical industry and construction.