【摘要】： 在1,1-二苯基乙烯(DPE)存在下,以甲基丙烯酸甲酯(MMA)為初始單體,偶氮二異丁腈(AIBN)為引發(fā)劑,采用本體聚合法制備出含有DPE片段的大分子引發(fā)劑(PMMA-DPE)。然后利用PMMA-DPE為引發(fā)劑,以苯乙烯(St)和馬來酸酐(MAn)為共聚單體,乙酸異戊酯為溶劑,采用自穩(wěn)定沉淀聚合法制備了單分散的聚苯乙烯-馬來酸酐(Poly (St-alt-MAn))的微球。 采用IR,UV-vis紫外光譜,1H NMR和GPC對產(chǎn)物的結(jié)構(gòu)進行了分析,并用SEM對聚合物微球的形貌進行了表征。系統(tǒng)地研究了PMMA-DPE的用量、單體濃度、單體配比、溫度以及不同反應(yīng)時間對聚合物相對分子量以及微球的形態(tài)、粒徑大小及分布的影響。 結(jié)果表明,由大分子前軀體PMMA-DPE引發(fā)聚合制備出的聚苯乙烯-馬來酸酐的微球平均粒徑在378-776 nm左右。相對于自引發(fā)聚合方法制備得到的微球,該聚合方法得到的微球具有很好的形貌且均一性較好,分散系數(shù)較低。隨著PMMA-DPE用量的增加,聚合物的相對分子量減小,產(chǎn)率增大,聚合物微球的粒徑減小,而粒徑分布系數(shù)增加。隨著單體濃度增加,相對分子量、轉(zhuǎn)化率以及微球的粒徑均增加,但分散系數(shù)基本不變。[St]:[MAn](摩爾比)的增加,聚合物的相對分子量增加,轉(zhuǎn)化率和粒徑都呈現(xiàn)先增加后減小的規(guī)律,粒徑分布大致不變。溫度升高,聚合物的相對分子量先增大后減小,單體轉(zhuǎn)化率和粒徑分散系數(shù)增加,粒徑減小。加入的溶劑丁酮量加大,聚合物的相對分子量先增大后減小,單體轉(zhuǎn)化率下降,粒徑變差。根據(jù)不同反應(yīng)時間下的聚合物的相對分子量、單體轉(zhuǎn)化率、微球的粒徑以及粒徑分布,提出了微球增長的可能機理。
[Abstract]:Macromolecular initiators (PMMA-DPE) containing DPE fragments were prepared by bulk polymerization with methyl methacrylate (MMA) as initial monomer and azodiisobutyronitrile (AIBN) as initiator in the presence of 1-diphenyl ethylene (DPE). Then the monodisperse polystyrene-maleic anhydride (Poly (St-alt-MAn) microspheres were prepared by self-stable precipitation polymerization using PMMA-DPE as initiator, styrene (St) and maleic anhydride (MAn) as comonomer and isoamyl acetate as solvent. The structure of the product was analyzed by IR,UV-vis 1H NMR and GPC, and the morphology of polymer microspheres was characterized by SEM. The effects of the amount of PMMA-DPE, monomer concentration, monomer ratio, temperature and reaction time on the morphology, particle size and distribution of polymer were studied. The results show that the average particle size of polystyrene-maleic anhydride prepared by macromolecular precursor PMMA-DPE initiation polymerization is about 378-776 nm. Compared with the microspheres prepared by the self-initiated polymerization method, the microspheres obtained by this polymerization method have good morphology, good uniformity and low dispersion coefficient. With the increase of PMMA-DPE content, the relative molecular weight of polymer decreases, the yield increases, the particle size of polymer microspheres decreases and the particle size distribution coefficient increases. With the increase of monomer concentration, the relative molecular weight, conversion rate and particle size of the microspheres increased, but the dispersion coefficient remained unchanged. The relative molecular weight of the polymer increased with the increase of [St]: [MAn] (molar ratio). The conversion rate and particle size increased first and then decreased, and the particle size distribution was almost unchanged. With the increase of temperature the relative molecular weight of the polymer first increases and then decreases while the monomer conversion and particle size dispersion coefficient increase and the particle size decreases. When the amount of butanone was increased, the relative molecular weight of the polymer first increased and then decreased, the monomer conversion decreased and the particle size became worse. According to the relative molecular weight, monomer conversion, particle size and particle size distribution of the polymer at different reaction times, the possible mechanism of the growth of the microspheres was proposed.
【學位授予單位】：北京化工大學
【學位級別】：碩士
【學位授予年份】：2010
【分類號】：O631.3

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