【作者】 宋师伟；

【导师】 王秀芬；

【作者基本信息】 北京化工大学 ， 材料学， 2008， 硕士

【摘要】 本论文制备了多种双亲性淀粉衍生物,包括聚苯乙烯接枝淀粉纳米晶、苄基淀粉纳米晶和辛基淀粉酯等。并通过FTIR、~1HNMR、XRD和SEM等对双亲性淀粉衍生物进行表征,并将所制得的双亲性淀粉纳米晶和天然橡胶共混制备了橡胶纳米复合材料,通过SEM观察复合材料的界面相容性,并研究其机械性能和动态粘弹性,分析了复合材料的抗湿滑性、低滚动阻力性能与双亲性淀粉纳米晶的关系。通过酸解法制备了淀粉纳米晶,并对淀粉纳米晶进行了双亲性改性。当硫酸浓度为3mol/L时,在45℃下酸解7天可以制得50nm左右的淀粉纳米晶。通过苯乙烯和淀粉纳米晶的接枝反应制备了聚苯乙烯接枝淀粉纳米晶。FTIR和~1HNMR表明聚苯乙烯成功的接枝到了淀粉纳米晶上,XRD表明接枝反应并未引起淀粉纳米晶晶型的改变。通过SEM可以观察到接枝反应后粒子尺寸增加。浸润性实验说明,双亲性淀粉纳米晶具有良好的双亲性,既可以分散在极性溶剂中,也可以在非极性溶剂中良好扩散。聚苯乙烯接枝淀粉纳米晶的制备受单体配比、引发剂浓度以及反应时间等因素的影响。较佳反应条件为:含3克淀粉纳米晶的100ml水溶液中,苯乙烯单体和淀粉纳米晶物质的量之比(M/SN)为1.5:1,引发剂用量为单体的0.5(wt)%,于72℃下反应10小时。此外,还分别通过非均相反应和固相法制备了双亲性的苄基淀粉纳米晶和辛基淀粉酯。随着反应浓度的增加,两种体系的取代度均增大。通过共沉淀技术制备了双亲性淀粉纳米晶/橡胶纳米复合材料。占橡胶重量15%的聚苯乙烯接枝淀粉纳米晶(M/SN=0.5)或5%的聚苯乙烯接枝淀粉纳米晶(M/SN=2)与橡胶共混,所得纳米复合材料机械性能得到明显改善;动态机械性能tanδ表明,其抗湿滑性得到明显提高,而滚动阻力可进一步通过填加炭黑、白炭黑得到降低;SEM则表明填料和基体具有良好的界面相容性。更多还原

【Abstract】 In this paper, many kinds of amphiphilic starch nanocrystals were prepared, including starch-g-polystyrene nanocrystals, benzyl starch nanocrystals and octyl starch nanocrystals ester. The amphiphilic starch derivatives were characterized through FTIR、~1HNMR、XRD and SEM. Composites were prepared through the mixture of amphiphilic starch nanocrystals and natural rubber. Interface compatibillity was seen from SEM. Mechanical property dynamic viscoelasticity were studied. The effect of amphiphilic starch nanocrystals on the high antiskid properties and low rolling resistance of composites was analyzed.Starch nanocrystals were prepared by acid hydrolysis of corn starch, and amphiphilic modification was conducted. Starch nanocrystals, the size of which was around 50nm, can be prepared hydrolyzed for 7 days under 45℃when sulfuric acid was 3mol/L. Starch-g-polystyrene nanocrystals were prepared by the polymerization of starch nanocrystals and styrene. Fourier transform infrared and ~1H nuclear magnetic resonance (~1H NMR) showed that polystyrene was successfully grafted to starch nanocrystals. XRD suggested crystalline structure is basically not changed after grafting polystyrene. SEM indicated that the size of the obtained amphiphilic starch nanocrystals was increased. Wettability experiments indicated that the prepared starch-g-polystyrene nanocrystals can be uniformly dispersed both in water phase and oil phase revealing excellent amphiphilicity.The effect of grafting copolymerization modification of starchnanocrystals and styrene is influenced by lots of factors, such as reaction temperature, initiator concentration, monomer concentration and reaction time etc. The optimal reaction conditions for the preparation were: in 100 ml of solution containing 3 g of starch nanocrystals, the molar ratio of monomer and starch (M/SN) was 1.5, the initiator concentration was 0.5% the mass of styrene monomer, and reaction was conducted under 72℃for 10 hours.Benzyl starch nanocrystals and octyl starch nanocrystals ester were prepared through heterogeneous polymerization and solid-state method. The value of DS of both systems increased with the increase of the concentration of reactants.Composites were prepared through the co-precipitation technology. When M/SN was 0.5 and the filler concentration was 15%, or M/SN was 2 and the filler concentration 5%, the mechanical property of obtained composites can be improved obviously. Tand from DMTA showed antiskid properties had been improved obviously and rolling resistance can be reduced from the increase of carbon black and white carbon black. SEM showed the interface had a good compatibillity.更多还原