Organic-inorganic hybrid efficient synergistic flame-retardant charring agent and preparation method thereof

Abstract

The invention relates to the technical field of macromolecular flame-retardant charring agents applied to polymer materials, and discloses an organic-inorganic hybrid efficient synergistic charring agent and a preparation method thereof, and the structural formula of the organic-inorganic hybrid efficient synergistic charring agent is shown in the specification. According to the charring agent, through nucleophilic substitution, two chlorine atoms on cyanuric chloride are sequentially substituted by p-xylylenediamine at different temperatures to form a linear macromolecular triazine intermediate taking p-xylylenediamine as a chain extender, then the temperature is increased, and the step of substituting chlorine on an upper side group of an intermediate is carried out by nano hydrotalcite and gamma aminopropyltriethoxysilane which are connected through hydroxyl according to the same principle as p-xylylenediamine and cyanuric chloride substitution modes. The charring agent has the characteristics of good charring property, high molecular weight, migration resistance, high temperature resistance and no influence on the mechanical properties of a matrix material, solves the problem that the charring property with good compactness and complete morphology cannot be formed due to the anti-migration property of a triazine derivative as the charring agent, and is applied to thermoplastic polyester elastomers.

Description

technical field [0001] The invention relates to the technical field of macromolecular flame-retardant char-forming agents applied to polymer materials, in particular to a novel organic-inorganic hybrid high-efficiency synergistic flame-retardant char-forming agent and a preparation method thereof. Background technique [0002] In the past decades, halogen-containing flame retardants (FRs) have been widely used to limit the flammability of polymeric materials. However, its flame retardant process usually brings many negative effects, such as the generation of corrosive and toxic fumes or volatiles, which will cause great damage to the environment and human health. Therefore, halogen-free flame retardants, especially intumescent flame retardants (IFR), can meet the needs of various industries due to their characteristics of halogen-free, low toxicity, droplet suppression, high flame retardant efficiency and low preparation cost. Due to the need for personal safety and environ...

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Problems solved by technology

However, EG as an intumescent flame retardant also has the following problems: First, EG has almost no chemical reaction with the polymer, the force between the charcoal layers is small, excessive expansion occurs during combustion, and the charcoal layer formed is often too loose and not dense enough , that is, the so-called "popcorn effect" occurs, and the flame retardant effect may not be as expected; the second is that the expanded carbon residue is observed under a scanning electron microscope and found to be "worm-like", and the gaps between the carbon layers are large and not dense enough. The flame retardant efficiency is not high; the third is that the larger the particle size of EG, the poorer its compatibility with the polymer matrix, resulting in a decrease in the mechanical properties of the material

Although char-forming agents mainly based on triazine derivatives have many advantages over other char-forming agents, they are easy to migrate to the surface of polymers due to small molecular weight and other reasons, and there have always been low flame retardant efficiency, poor thermal stability and formation. The problem of poor carbon performance leads to the inability to form a good-looking carbon layer within the required time, and it is impossible to achieve efficient coordination and coordination of the three sources

As a commonly used inorganic flame retardant synergist, nano-hydrotalcite has a synergistic flame-retardant effect with IFR, but it has poor compatibility with polymers, and it is difficult to uniformly disperse in the polymer matrix, which seriously affects the performance of nano-hydrotalcite and IFR. Synergistic Flame Retardant Effect of IFR in Polymer Materials

The above problems eventually lead to unsatisfactory flame retardant effect

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