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HIPS / magnesium hydroxide modified and performance halogen free flame retardant composites

Author: ZhouChenGang
Tutor: YangZuo；ZhouDao
School: Nanjing University
Course: Chemical Engineering
Keywords: HIPS / magnesium hydroxide composite flame retardant materials Self - compatibilization technology Macromolecular modifier Compatibility Structure-Activity Relationship
CLC: TB332
Type: Master's thesis
Year: 2011
Downloads: 120
Quote: 0
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Abstract

In recent years, with the growing importance of the ecological environment, the development of halogen-free flame retardant polymer materials attracted much attention. However, due to the problem of compatibility between the inorganic flame retardant particles and the matrix of organic polymer materials is not so good, while the material is flame retardant effect is bound to make other properties of composite materials, such as mechanical properties suffered great losses. In order to balance between the various aspects of performance of the polymer material, to improve the uniformity of the flame retardant particles are dispersed in the polymer matrix, and to avoid agglomeration, to improve compatibility, there is no doubt in the composite machining process is essential. Compound flame retardant for the high impact polystyrene (HIPS) and magnesium hydroxide (MH) material system, and the self-compatibilizer sulfonated pretreatment, first a small amount of HIPS as a modifying agent directly to the sulfonated HIPS replace the traditional polystyrene - butadiene - styrene (SBS), obtained HIPS / MH composite flame retardant materials found the final flame retardant and mechanical properties of the polymer materials have been effectively improved. In addition, the paper by scanning electron microscopy (SEM), thermal gravimetric analysis (TG), particle size and particle size distribution analysis of a variety of characterization methods, filled flame retardant particles and the morphology of the composite structure, respectively. focuses on macromolecular modifier sulfonation degree and add the amount of composite material modified impact discussed modifier modification mechanism, establish a reasonable structure-activity relationship provides a useful reference for the actual production. Best results are as follows: (1) the degree of sulfonation is one of sulfonated important structural parameter of the HIPS material, the degree of sulfonation size determines the strength of polarity of the modifying agent. Experimental results show that: by different degrees of sulfonation HIPS modified HIPS / MH composites mechanical properties have been improved to a certain extent, and the degree of sulfonation of about 20-30% was obtained composite material has the best overall performance, and a sulfo of too low or too high can not be achieved to improve the best results of the compatibility between the inorganic particles and the polymer matrix. Sulfonated too low, of sulfonated HIPS and MH particles effect is not sufficient, dispersion decreased; while sulfonation is too high, the polarity of the modifier is too strong, poor compatibility with the polymer matrix, which are not conducive to the material further improvement of the performance. Thus; sulfonated HIPS degree of sulfonation of the modifying agent should be controlled within a suitable range; (2) for the the different the sulfonation degree HIPS modifier, the amount of the modifying agent on the material properties were investigated. The results consistently show that: sulfonated HIPS addition amount of about 10% (the relative MH additive amount of) the composite material obtained has the best overall performance, the amount of modifier is too small or too large, are not exhibited the best modification effect . This is due to the final properties of the composite material depend on the polymer matrix of the composite material and the compatibility between the inorganic filler particles, the compatibility of the two phases in the composite material filled with an inorganic related to the morphology of the particles themselves, and modifiers. Modifier added on the one hand to improve the compatibility of the two phases, and the other hand, the original morphology of the inorganic filler particles has deteriorated: so that its particle size becomes large and widened particle size distribution, is not conducive to composite materials interphase compatibility improved, so the amount of modifier should be controlled within a suitable range, in order to achieve optimal results. In addition, compared with the use of traditional SBS toughened HIPS / MH composites using self-compatibilization technology, use of sulfonated HIPS modifier directly modified polymer material has obvious advantages in fire-retardant and mechanical properties ; but also significant savings in the cost of full compliance with the needs of the actual production application.

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