【作者】 任亮；

【导师】 那辉；

【作者基本信息】 吉林大学 ， 高分子化学与物理， 2011， 博士

【摘要】 高分子材料在应用过程中,刚性和韧性是两个很重要的参数。因此,塑料改性的研究是高分子材料科学研究的重要课题。ABS树脂是世界上应用最广泛的工程塑料之一。透明ABS树脂除具有通用ABS树脂机械性能的同时,还具有良好的透明性。研究透明ABS树脂的制备方法具有重要的理论意义与实际价值。核壳结构改性剂可以作为透明ABS树脂的增韧剂,提高共混物的冲击强度和透光率。核壳结构改性剂主要特点是其粒子尺寸可控,并且在分散到基体树脂中保持不变。本论文采用乳液聚合的方法合成了具有核壳结构的改性剂丙烯腈-丁二烯-苯乙烯共聚物和甲基丙烯酸甲酯-丁二烯-苯乙烯共聚物,将其用于透明ABS树脂的增韧,主要的研究内容和结论如下：1.采用乳液聚合技术制备出了聚丁二烯胶乳和丁苯胶乳,采用悬浮聚合技术制备出了MSAN和MS共混物,采用乳液接枝聚合技术合成了ABS和MBS接枝粉料,将核壳改性剂与基体树脂共混制备透明ABS树脂,使其具有优良的性能。2.采用乳液聚合技术合成了不同系列的SAN共聚物粉料和a-MSAN共聚物粉料。将其与聚甲基丙烯酸甲酯(PMMA)熔融共混制得了PMMA/SAN和PMMA/a-MSAN共混物,考察了共混体系的相容性。结果发现：当SAN中St/AN为50/50,65/35,95/5时,PMMA和SAN是一个不相容体系；当SAN中St/AN为75/25时,PMMA和SAN是一个相容体系。在用a-MSt部分替代St合成的a-MSAN共聚物与PMMA形成的PMMA/a-MSAN共混体系中,a-MSAN共聚物的AN结合量为15～25wt%时,PMMA和a-MSAN共聚物为相容体系。用a-MSt全部替代St合成不同AN结合量的a-MSAN共聚物与PMMA形成的PMMA/a-MSAN共混体系中,a-MSAN共聚物的AN结合量为15～25wt%时,PMMA和a-MSAN共聚物仍为相容体系。进一步考察了a-MSAN共聚物中a-MSt的含量对共混物相容性的影响。AN含量为25wt%的PMMA/α-MSAN共混物在整个共混组成范围内都是相容的。3.采用乳液聚合方法,制备不同特性的MBS核壳结构改性剂并用于PMMA/SAN的增韧,考察了MBS的特性对PMMA/SAN/MBS共混体系的影响,结果表明,存在一个最佳粒径范围使MBS更能有效地对PMMA/SAN进行增韧,而且,PMMA/SAN/MBS共混物具有很高的透光率和很低的雾度。存在一个最佳凝胶含量范围使MBS更能有效地对PMMA/SAN进行增韧,而且,PMMA/SAN/MBS共混物具有很高的透光率和很低的雾度。随着MBS核中苯乙烯结合量的增加,PMMA/SAN/MBS共混物的冲击强度和透光率先增大在减小,而雾度先减小在增大。当苯乙烯以接枝的方式结合时,有利于共混物的韧性；当苯乙烯以共聚方式结合时,有利于共混物的光学性能。PMMA/SAN/PB-g-SAN共混物比PMMA/SAN/SBR-g-SAN共混物冲击强度高,而光学性能优良。4.采用乳液聚合技术合成聚丙烯酸丁酯、丙烯酸丁酯-苯乙烯共聚物和丁二烯-苯乙烯-丙烯酸丁酯共聚物,采用乳液接枝技术制备MABS核壳改性剂,研究聚合过程中的动力学以及MABS核壳改性剂对PMMA的增韧。结果表明：聚合反应中,随着体系固含量变大,共聚物粒径增加,转化率不断变大。随着MABS核壳改性剂核里丙烯酸丁酯的增加,PMMA/MABS共混物的冲击强度逐渐减小。透光率先增大后减小,雾度先减小后增大。随着MABS核壳改性剂核粒径的增加,PMMA/MABS共混物的冲击强度先增大后减小,在粒径为269nm时出现最大值。透光率先增大后基本不变,雾度先减小后基本不变。通过TEM可以观察到MABS核壳改性剂在PMMA树脂中的分散,这与MABS/PMMA共混物的性能相一致。更多还原

【Abstract】 The stiffness and toughness of polymer materials are two important factors for their practical applications. Hence, investigation on the modification of plastics is a focus of polymer material science. ABS resin is one of the important engineering plastic extensively used in the world. Transparent ABS resin has not only general ABS resin mechanical properties, but also good transparency. Investigation on the preparation method of transparent ABS resin has important academic and applied values. Core-shell modifiers can act as impact modifiers to toughen the transparent ABS resin and improve their notched impact strength and transmittance.The advantage of Core-shell modifiers is that the particle size of core-shell modifiers has been set during their synthesis and kept constant when they are blended with matrix resins. In our study, the core-shell modifier, including acrylonitrile-butadiene-styrene and methyl methacrylate-butadiene-styrene copolymers were synthesized by seed emulsion polymerization methods, and these copolymers were used to tough transparent ABS resin. The main research work and conclusions are as follows:1. Polybutadiene (PB) and Styrene-Butadiene(SBR) latex rubbers were synthesized by emulsion polymerization. Methylmethacrylate-styrene(MS) resin,methylmethacrylate-styrene-acrylonitrile (MSAN) resin were prepared by suspension polymerization. Then a series of poly Acrylonitrile-Butadiene-Styrene (ABS) and poly Methyl-methacrylate-Butadiene-Styrene (MBS) were successfully synthesized by grafting Acrylonitrile-styrene copolymer (SAN) onto Polybutadiene latex rubber particles or by grafting styrene and methylmethacrylate monomer onto Styrene-Butadiene latex rubber particles with seeded emulsion polymerization techniques. Transparent Acrylonitrile-Butadiene-Styrene (ABS) resin with good properties was prepared by blending core-shell modifiers with matrix.2. Styrene-acrylonitrile copolymer (SAN) and a-methylstyrene-acrylonitrile copolymer (a-MSAN) with different components was synthesized by emulsion polymerization. Then, PMMA/SAN blend and PMMA/a-MSAN blend were prepared by blending SAN or a-MSAN with PMMA resin. The miscibility of PMMA/SAN blend and PMMA/a-MSAN blend was investigated. The result indicated PMMA and SAN was a immiscible system when St/AN was 50/50、65/35、95/5 in styrene-acrylonitrile copolymer (SAN).However, PMMA and SAN was a miscible system when St/AN was 75/25 in styrene-acrylonitrile copolymer (SAN). PMMA/a-MSAN blend, in which a-MSt partly substituted St, was a miscible system when the content of AN in a-MSAN was 15-25%. PMMA/a-MSAN blend, in which a-MSt substituted St, was also a miscible system when the content of AN in a-MSAN was 15-25%.The influence of the content of a-MSt in a-MSAN on the miscibility of PMMA/a-MSAN blend was investigated. PMMA and a-MSAN was a miscible system in entire composition when the content of AN in a-MSAN was 25%.3. MBS core-shell particles with different structure synthesized by seed emulsion polymerization were used as impact modifier of PMMA/SAN. Results showed that MBS effectively toughened PMMA/SAN in the range of the appropriate sizes. PMMA/SAN/MBS blend had the higher transmittance and the lower haze. MBS effectively toughened PMMA/SAN in the range of the appropriate gel content. PMMA/SAN/MBS blend had the higher transmittance and the lower haze. With the increase of St content arranged in the core of MBS, the impact strength and the transmittance of PMMA/SAN/MBS blend increased and then decreased, the haze of PMMA/SAN/MBS blend decreased and then increased. When St was grafted onto the PB rubber, the resistance of the blend was improved. When St was copolymerized with butadiene in MBS, the optical property of the blend was improved. Compare with PMMA/SAN/SBR-g-SAN blend, PMMA/SAN/PB-g-SAN blend had the higher impact strength and better optical property.4. Poly butyl acrylate, butyl acrylate-styrene copolymer and Butadiene-styrene-butyl acrylate copolymer were synthesized by emulsion polymerization. MABS core-shell modifier was prepared with emulsion grafting polymerization. The kinetics of polymerization and toughening PMMA by MABS core-shell modifier were investigated. Results indicated that copolymer particle size and converse rate increased as solid content increased in the polymerization. The impact strength of PMMA/MABS blend decreased, the transmittance of PMMA/MABS blend increased and then decreased and the haze of PMMA/MABS blend decreased and then increased with the increase of the content of butyl acrylate in core of MABS. The impact strength of PMMA/MABS blend decreased and then increased and got to the maximum value when the particle is 269nm, the transmittance of PMMA/MABS blend increased and then invaried and the haze of PMMA/MABS blend decreased and then invaried with the increase of the particle size of butyl acrylate in core of MABS. It is found that from TEM MABS modifier dispersed in PMMA, which is consistence with the property of PMMA/MABS blend.更多还原