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利用可控微乳液法合成粒径19~200 nm,且呈球状分布均匀的聚甲基丙烯酸甲酯/聚(异戊二烯-co-苯乙烯)(PMMA/PIS)核壳纳米粒子,通过水合肼产生原位氢的技术,对合成的PMMA/PIS乳液体系进行直接常压氢化,对影响氢化度的因素、聚合物氢化前后结构、热性能进行了研究.结果显示,聚合物粒径、水合肼及双氧水用量等都是影响聚合物的氢化度的因素.研究发现,氢化以PMMA为核,PIS为壳的核壳结构乳液可以显著提高PIS氢化程度,减少氢化过程中凝胶产生.利用FTIR、~1H-NMR、Na_2S_2O_3滴定法测定了乳液的氢化度.结果表明,当聚合物粒径小于200 nm时,乳液氢化度可达到95%以上,且无凝胶现象产生.GPC结果证明了反应是氢化而非凝胶过程.利用TEM、DLS测试了氢化后乳液的核壳结构和粒径.实验结果显示,PMMA/HPIS为核壳纳米结构.TGA结果显示,当氢化度为98%时,聚合物耐热性提高41°C.
Polymethylmethacrylate / poly (isoprene-co-styrene) (PMMA / PIS) core-shell nanoparticles with particle sizes of 19-200 nm and uniform distribution were prepared by controlled microemulsion method. Hydrazine hydrate in situ hydrogen technology, the synthesis of PMMA / PIS emulsion system by direct atmospheric hydrogenation, factors that affect the degree of hydrogenation, the structure of the polymer before and after hydrogenation and thermal properties were studied.The results show that the polymer particle size, Hydrazine hydrate and hydrogen peroxide dosage are the factors influencing the degree of hydrogenation of the polymer.It is found that the core-shell emulsion with PMMA as core and PIS as shell can significantly increase the degree of hydrogenation of PIS and reduce the gel formation in the hydrogenation process. FTIR, ~ 1H-NMR and Na_2S_2O_3 titrimetric methods were used to determine the degree of hydrogenation of the emulsion.The results showed that the degree of hydrogenation of the emulsion can reach more than 95% when the particle size of polymer is less than 200 nm, The reaction was hydrogenated rather than gel.The core-shell structure and particle size of the hydrogenated emulsion were tested by TEM and DLS.The experimental results showed that PMMA / HPIS was a core-shell nanostructure.TGA results show that when the degree of hydrogenation is 98% , The polymer heat resistance increased 41 ° C.