【作者】 张凯；

【导师】 傅强；

【作者基本信息】 四川大学 ， 材料学， 2005， 博士

【摘要】 本论文的研究课题来源于国防预研项目,研究目的是制备出粒径≤10μm的包覆有纳米活性铝粉的聚合物复合粒子,并在此基础上优化制备工艺,进一步提高纳米铝粉的活性和包覆率。纳米铝粉具有较高的表面能和表面活性,容易发生团聚,且与水、氧气反应而失去活性。如何在制备纳米铝粉/聚合物复合粒子的过程中,既保持纳米铝粉活性,又确保纳米铝粉具有较好的分散性,成为了本课题研究的难点。 由于超声波作用下辅助引发分散聚合反应的研究未见报道,为了确保纳米铝粉/聚苯乙烯复合粒子能够制备成功,本课题的研究思路为:首先,对超声波作用下辅助引发苯乙烯及甲基丙烯酸甲酯的分散聚合反应规律进行研究;然后,对超声波作用下辅助引发苯乙烯的分散聚合反应制备惰性无机粒子/聚苯乙烯复合粒子（SiO₂/PS、TiO₂/PS、Ag/PS）的规律进行研究;最后,在以上研究的基础上,对超声波作用下辅助引发苯乙烯的分散聚合反应制备活性无机粒子/聚苯乙烯复合粒子的规律进行研究,从而实现Al/PS复合粒子的制备。 为了进一步拓宽无机/有机复合粒子的制备方法,本文还对超声波作用下辅助引发甲基丙烯酸甲酯的分散聚合反应制备惰性无机粒子/聚甲基丙烯酸甲酯复合粒子（SiO₂/PMMA、Ag/PMMA）及超声波场下利用相分离方法制备SiO₂/PA-6及Ag/PA-6复合粒子的规律进行研究。 1.对超声波作用下辅助引发苯乙烯及甲基丙烯酸甲酯的分散聚合反应规律进行了系统的研究。首先,研究了超声波场的输出功率及作用时间对苯乙烯分散聚合反应的影响,从而确定了合适的超声波场的试验条件（400W×3.0h）。同时,采用单因素试验方法,对超声波场下苯乙烯分散聚合反应的反应规律进行了初步研究。然后,采用均匀设计方法对超声波场下苯乙烯和甲基丙烯酸甲酯分散聚合更多还原

【Abstract】 The question for study in this paper comes from advance research in national defense, and the research aims are to prepare polymer composite particles encapsulated active nano-aluminium with size less than 10.0 μ m. On the base of research, the preparation technology will be optimized, and the activity of nano-aluminium in composite particles and encapsulation ratio will be enhanced. Nano-aluminium tends to agglomerate and reacts with water or oxygen because of high surface energy and activity. How to keep high activity and well dispersibility of nano-aluminium during preparing aluminium /polymer composite particles is a big challenge in this study.To our knowledge, there is no description in the literature of dispersion polymerization assist-initiated through ultrasonic irradiation. Firstly, the researches on influencing factors in dispersion polymerization of styrene and methyl methacrylate assist-initiated through ultrasonic irradiation were carried out. Secondly, the researches on influencing factors of preparing inorganic inert particle/PS composite particles with in situ dispersion polymerization of styrene assist-initiated through ultrasonic irradiation were carried out. Thirdly, on the basis of above researches, the researches on influencing factors of preparing inorganic active particle Al/PS composite particles with in situ dispersion polymerization of styrene assist-initiated through ultrasonic irradiation were carried out, and Al/PS composite particles with well morphology and high encapsulation were prepared with success.In order to broaden the preparation methods of inorganics/organics composite particles, the researches on influencing factors of preparing PMMA particles and SiO₂/PMMA, Ag/PMMA composite particles with dispersion polymerization assist-initiated through ultrasonic irradiation were carried out. Moreover, the researches on influencing factors of preparing PA-6 particles and SiO₂/PA-6, Ag/PA-6 composite particles with phase separation were carried out.1. The systemic researches on influencing factors in dispersion polymerization of styrene and methyl methacrylate assist-initiated through ultrasonic irradiation were carried out. Firstly, the influences power of out and time of ultrasonic irradiation on St dispersion polymerization were investigated, and the right reaction condition was confirmed as 400WX3.0h. Meanwhile, adopting single factor test methods, the reaction laws of St dispersion polymerization assist-initiated through ultrasonic irradiation were studied. Secondly, The uniform design methods were used to arrange four-factor and eight-level experiment of St and MMA dispersion polymerization assist-initiated through ultrasonic irradiation, including monomer concentration, initiator concentration, stabilizer concentration and ratio of alcohol and water. The stepwise regression technique was adopted to analyze the test results. The mathematical modes between molecular weight, size and size distribution of PS and PMMA and four influencing factors were established, and their reliabilities were evaluated. Although the predicted values from regression equation were different from the observed values （relative divergences were less than 10%）, the regression equation could use for design of polymer particles and mechanism research. All above researches could use for optimization of polymerization reaction conditions under ultrasonic irradiation. Thirdly, the distributions of temperature field of dispersion polymerization under ultrasonic irradiation were calculated and simulated by finite element analysis methods. Finally, the reaction mechanism of dispersion polymerization assist-initiated through ultrasonic irradiation was put forward, and the polymerization process was stepwise in different regions.2. The researches on influencing factors of preparing inorganic inert particle/PS composite particles with in situ dispersion polymerization of styrene assist-initiated through ultrasonic irradiation were carried out. Firstly, according to different surface characteristics of inorganic inert particle, right surfactant should be selected, and the surface characteristics of inorganic inert particle should be treated to be hydrophobicity under ultrasonic irradiation. As for SiO2, TiO2 et al. inorganic oxide particles, surface treatment could be conducted with cation surfactant CTAB under alkalescence medium. As for Ag particles, surface treatment could be conducted with anion surfactant SDS under neutrality medium. Secondly, the dispersion polymerization of styrene in the presence of SiCK or T1O2 or Ag particles was initiated with N2 purging through ultrasonic irradiation by taking its advantages of multieffect, i.e., dispersion, crushing, activation, and initiation. Finally, the influencing factors of polymerization process were investigated, and themorphology, size and size distribution, structure of composite particles were characterized with SEM, TEM, FTIR, XPS, TGA and DSC.3. The researches on influencing factors of preparing inorganic active particle Al/PS composite particles with in situ dispersion polymerization of styrene assist-initiated through ultrasonic irradiation and activity analysis were carried out. Firstly, the influences sorts and amount of surfactant, composition of reaction system on Al/PS composite particles were investigated. The results showed that nano-aluminium could absorb PEG through physical and chemical adsorption, and the ability of stability and adsorption of nano-aluminium particles could be improved. Once the reaction condition reached, the in situ dispersion polymerization of St in the presence of nano-aluminium particles was initiated. The steric hindrance effect of PEG could weaken the absorption ability of nano-aluminium particles and primary nucleus, and lead to different reaction laws from the dispersion polymerization in the presence of SiO2 or Ag particles. Secondly, Al/PS composite particles with different aluminium content were prepared under optimization conditions. With increasing amount of nano-aluminium particles, the encapsulation ratio of composite particles decreased. The Al/PS composite particles had good sphericity, smooth surfaces and well dispersibility. Finally, the activities of nano-aluminium particles were analyzed before and after encapsulation. Al/PS composite particles with different aluminium content had almost equal activity. The activity aluminium content of Al/PS composite particles was 76.07%. Stored in a sealed bag in natural condition and in an oxygen bottle after 30d, the activity aluminium content of Al/PS composite particles were 76.06% and 74.81%, respectively. The results showed that the activity aluminium content could keep for long time after encapsulation by PS.4. The researches on influencing factors of preparing PMMA particles and SiO2/PMMA, Ag/PMMA composite particles with dispersion polymerization assist-initiated through ultrasonic irradiation were carried out. Firstly, the influence composition of reaction system on dispersion polymerization of MMA was studied, including monomer concentration, initiator concentration, stabilizer concentration and ratio of methanol and water. The reaction laws of dispersion polymerization of MMA assist-initiated through ultrasonic irradiation were similar to those of dispersion polymerization of St. Secondly, adopting similar preparation technology to SiO2/PS and Ag/PS composite particles, SiO2/PMMA and Ag/PMMA composite particles were prepared. The results showed that CTAB had unfavorable effect on polymerization degree of MMA. SiOVPMMAcomposite particles had abnormity, broad size distribution, poor dispersibility and low encapsulation ratio. On the other hand, Ag/PMMA composite particles had better morphology, size distribution and dispersibility than that of SiO2/PMMA and Ag/PS composite particles. With increasing amount of Ag particles, the encapsulation ratio of composite particles decreased. Finally, on the base of systemic researches on dispersion polymerization of St and MMA in the present of inorganic nano-particles, the "megranate" model describing the nucleation and growth process about preparation of inorganics/organics composite particles was put forward.5. The researches on influencing factors of preparing PA-6 particles and SiO2/PA-6, Ag/PA-6 composite particles with phase separation were carried out. Firstly, the PA-6 particles prepared by dropping nonsolvent method and cooling temperature method had different characteristic, respectively. The former had loose surface structure and well dispersibility, and the latter had compact surface structure and poor dispersibility. Secondly, through combining dropping nonsolvent method and cooling temperature method, the syntheses phase separation method was carried out to prepare PA-6 particles, which had common advantage with above two kinds of PA-6 particles. Then, the influencing factors of syntheses phase separation method were investigated. Thirdly, SiO2/PA-6 and Ag/PA-6 composite particles were prepared with syntheses phase separation method in the present of SiC>2 or Ag particles in PA-6 formic acid solution under ultrasonic irradiation. The former had abnormity and uneven surface. The most part of SiO2 particles encapsulated by PA-6, and a fraction of SiO2 particles lied in the surfaces of PA-6 particles. The latter had abnormity and compact surface structure. The almost whole of Ag particles encapsulated by PA-6, and no dissociative Ag particles surrounded PA-6 particles. On the conditions of same amount of inorganic particles, composite particles prepared with phase separation had larger encapsulation ratio than those prepared with dispersion polymerization. Finally, the preparation mechanism of inorganics/organics composite particles through syntheses phase separation method under ultrasonic irradiation was put forward.更多还原