Modified Vinylamine Polymers for Papermaking Strength and Drainage
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Solution Overview
Problem
Current vinylamine-containing polymers used in papermaking lack versatility in functional groups, limiting their application properties and efficiency in paper strength enhancement and water treatment processes.
Innovation Solution
Development of vinylamine-containing polymers with randomly distributed repeating monomer units modified by post-polymerization chemical modification, incorporating cationic, anionic, hydrophobic, hydrophilic, and amphoteric functional groups, and their derivatives, which are reacted with alkylating or acylating agents to enhance molecular weight and charge distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If vinylamine-containing polymers are used with high density of primary amine groups to achieve strong hydrogen bonding ability and high wet strength, then paper wet strength is improved, but the versatility in functional groups is limited
Solution Approach 1:
The patent applies parameter changes by systematically modifying the functional group composition of vinylamine-containing polymers through post-polymerization chemical modification. Different degrees of substitution and types of functional groups (cationic, anionic, hydrophobic, hydrophilic, amphoteric) are introduced to create a series of polymer variants with tuned properties, resolving the contradiction between maintaining strong hydrogen bonding ability and achieving functional group versatility.
Solution Approach 2:
The patent creates composite functional structures by combining vinylamine backbone with multiple types of functional groups attached through chemical modification. This composite approach allows the polymer to simultaneously exhibit strong hydrogen bonding from the vinylamine units and diverse functionalities from the attached groups, resolving the contradiction between strength and versatility.
2Productivity
If polyvinylamine is used as retention aid and drainage aid to improve flocculation efficiency and drainage rate, then papermaking process efficiency is improved, but application properties are limited by single functional character
Solution Approach 1:
The patent achieves multi-functionality by creating vinylamine-containing polymers that can simultaneously perform retention aid, drainage aid, and strength enhancement functions. Through controlled introduction of different functional groups, the polymers can adapt to various papermaking conditions and requirements, resolving the contradiction between productivity improvement and application versatility.
3Stability of the object's composition
If copolymers containing vinylamine units and additional vinyl units are used to reduce cationic charge density, then polymer solubility is improved, but the density of vinylamine units is reduced
Solution Approach 1:
The patent applies parameter changes by controlling the composition ratio of vinylamine units to additional vinyl units in the copolymer, and by controlling the degree of substitution of functional groups. This allows optimization of the balance between polymer solubility (improved by lower charge density) and hydrogen bonding ability (maintained by sufficient vinylamine unit density), resolving the contradiction between these two parameters.
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 modified polymers exhibit improved strength and retention properties in paper products and enhanced performance in water treatment, including better drainage, flocculation, and stickies control, with optimized molecular weight and charge density for effective pulp fiber interaction.
Implementation Method 1
These polymers possess strong hydrogen bonding ability as a result of this high density of primary amine groups
Implementation Method 2
Polyvinylamine is highly cationic due to its high density of primary amine or amidine functionality
Implementation Method 3
U.S. Pat. No. 4,421,602 discloses a partially hydrolyzed, water-soluble polymer of N-vinylformamide that contains N-vinylformamide units and vinylamine units. It also discloses use of polyvinylamine and a 50% hydrolyzed polyvinylformamide to increase flocculation efficiencies, fines retention, and the drainage rate of pulp fiber in papermaking processes
Data Source
AI summary
Vinylamine-containing polymers are disclosed where the amine groups are substituted with (1) cationic functional groups, (2) anionic functional groups, (3) hydrophobic functional groups, (4) hydrophilic functional groups, (5) functional groups that impart amphoteric characteristics to the polymers, or (6) combinations thereof. Also disclosed are processes for preparing such polymers, as well as compositions comprising such polymers. Among other applications, these polymers can be used in papermaking applications as dry strength additives, wet strength additives, retention aids, drainage aids, and pitch and stickies control agents.