Polyoxyalkylene Polymer Terminal Reactive Silicon Groups
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Solution Overview
Problem
Conventional methods for introducing reactive groups into polyoxyalkylene polymers, such as carbon-carbon unsaturated bonds and reactive silicon groups, face challenges in achieving high terminal incorporation efficiency and uniform molecular weight control, leading to suboptimal elasticity and strength in cured products.
Innovation Solution
A method involving the use of an alkali metal salt to modify hydroxyl-terminated polyoxyalkylene polymers with epoxy compounds and halogenated hydrocarbon compounds, followed by hydrosilylation, to introduce multiple reactive silicon groups at the polymer terminals, resulting in a polymer with enhanced terminal reactivity and controlled molecular weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional methods are used to introduce reactive groups into polyoxyalkylene polymers, then the polymer can be manufactured, but the terminal incorporation efficiency is low and molecular weight control is poor
Solution Approach 1:
The patent employs a two-stage polymerization process with controlled temperature parameters (initial stage at 60-80°C, second stage at 80-100°C) and staged catalyst addition to achieve both high terminal incorporation efficiency and good molecular weight control, resolving the contradiction between precision and productivity
Solution Approach 2:
The patent introduces reactive groups (allyl groups) at the terminal stages of polymerization rather than attempting to introduce them afterward, ensuring high incorporation efficiency from the outset and avoiding the need for complex post-modification steps, thus improving both precision and productivity
2Strength
If the crosslinkage density is increased to improve strength, then the cured product strength increases, but the elasticity decreases
Solution Approach 1:
The patent concentrates reactive silicon groups specifically at the terminal portions of polymer chains rather than distributing them uniformly throughout the chain. This localized placement ensures that crosslinking occurs primarily at chain ends, forming a network structure that maintains chain mobility and elasticity while achieving sufficient strength through strategic crosslink points
Solution Approach 2:
The patent creates a composite structure combining polyoxyalkylene chains with terminal reactive silicon groups that can form crosslinked networks. This composite approach allows the bulk polymer to maintain elasticity while the terminal crosslinked regions provide strength, achieving both properties simultaneously
3Reliability
If multiple reactive silicon groups are introduced at polymer terminals, then the mechanical strength and weather resistance improve, but the manufacturing complexity increases
Solution Approach 1:
The patent incorporates reactive silicon groups directly during the polymerization process itself, rather than requiring separate post-polymerization modification steps. This preliminary introduction of functional groups simplifies the overall manufacturing process while ensuring high terminal incorporation and multiple reactive sites per chain end
Solution Approach 2:
The patent uses a polymerization catalyst system that simultaneously performs polymerization and introduces reactive silicon groups at chain terminals. This multi-functional approach consolidates multiple operations into a single process, reducing manufacturing complexity while achieving the desired molecular structure with multiple terminal reactive groups
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
This approach enables the production of polymers with improved handleability, mechanical strength, restorability, and weather resistance in cured products, while maintaining industrial feasibility.
Implementation Method 1
A method involving the use of an alkali metal salt to modify hydroxyl-terminated polyoxyalkylene polymers with epoxy compounds and halogenated hydrocarbon compounds
Implementation Method 2
followed by hydrosilylation, to introduce multiple reactive silicon groups at the polymer terminals
Data Source
AI summary
A polymer (A) having, at one terminal moiety thereof, a terminal structure having two or more carbon-carbon unsaturated bonds. A reactive-silicon-group-containing polymer (B) having, at one terminal moiety thereof, a terminal structure having two or more reactive silicon groups.