【作者】 刘敏；

【导师】 姚臻； 曹堃；

【作者基本信息】 浙江大学 ， 化学工程， 2006， 硕士

【摘要】 等规聚丙烯（iPP）是重要的聚烯烃品种之一，呈刚性，耐热性、耐化学性好，且密度低，无毒、易加工，是一种性能优良的热塑性合成树脂。但是它低温韧性差，粘合性差，与其它聚合物的相容性差，因此工业应用受到一定的限制。通过与极性单体共聚的方法将极性官能团引入iPP链中，不但能保持其原有的性能，而且还有效地改善其韧性、表面性能（如粘合性、染色性和印刷性）、与溶剂或其它聚合物的相容性等。本文采用茂金属催化剂rac-[Et（Ind）₂]ZrCl₂实现了丙烯与极性单体3-丁烯-1-醇的共聚合。极性单体中极性基团的存在一方面会改变烯烃的配位聚合反应活性，另一方面它还能与配位催化剂络合形成稳定的配合物，阻止共聚反应的进一步进行。因此，当选用茂金属催化体系时，极性单体一般须经保护之后才能与烯烃进行共聚。本文采用三异丁基铝（TIBA）将3-丁烯-1-醇进行保护处理，二者在-78℃低温和室温下先后反应一段时间，得到共聚单体BB1。通过对共聚产物¹H、¹³C核磁谱图、红外谱图的分析，确认采用基团保护法可成功制备丙烯与极性单体3-丁烯-1-醇的共聚物。本文还考察了聚合温度、极性单体加入量、Al／Zr摩尔比、催化剂浓度等因素对共聚合过程及其产物结构和性能的影响。发现对聚合活性而言，存在一最佳聚合温度（50⁰C），在此温度下活性最高；极性单体的加入会降低聚合活性，其用量越大，活性下降越多；若要提高活性，可增加催化剂浓度及Al／Zr摩尔比。聚合物的分子量随聚合温度、催化剂浓度、Al／Zr摩尔比的增加而减少，但是增加极性单体加入量可提高聚合物的分子量。欲提高共聚物中极性单体的摩尔分率，除去增加极性单体加入量外，还可适当降低Al／Zr摩尔比或升高聚合温度、催化剂浓度。共聚物的熔点随分子量、极性单体摩尔分率的增加而提高。另外，为了控制颗粒的形态，解决粘釜的问题，降低MAO的用量，本文进行了催化剂的负载化研究。结果表明，采用负载催化剂后，粘釜问题得到了改善。各实验因素对负载催化剂聚合过程及其产物结构与性能的影响，与均相催化法一致，所得共聚物中-OH摩尔含量、粘均分子量及Tm均有所升高，但是负载后催化剂的活性降低明显。更多还原

【Abstract】 As one of the most important commodity polyolefins, commercial polypropylene is characterized by good impact strength, rigidity and chemical resistance and is low in cost. However, the lack of functional groups in polypropylene significantly limits the areas in which it can be applied. Introducing polar groups to polypropylene chains is one effective way to improve the character of polypropylene. The addition of functional groups to polypropylene by means of copolymerization can not only keep the intrinsic performance of polypropylene, but also change some important properties of polypropylene, such as toughness, adhesion properties, surface performances and compatibility with solvent and other polymers.In this work, the copolymerization of propylene and 3-buten-1-ol as polar monomer was achieved by using metallocene catalyst rac-[Et（Ind）₂]ZrCl₂. Functional groups in polar monomers not only influence the reactive activity of coordinative polymerization, but also form stable complex with the coordinative catalyst, which can prevent copolymerization from taking place. Therefore, polar group in monomers should be protected before copolymerization with olefins. In this work, hydroxyl end-group of 3-buten-1-ol was by protected reacting with TIBA at -78℃ and room temperature sequentially. The resultant of this reaction was termed as BB1. ¹H-NMR, ¹³C-NMR and FTIR have confirmed that the copolymer of propylene and 3-buten-1-ol were obtained through copolymerization of propylene and BB1.Effects of polymerization temperature, amount of added BB1, Al/Zr molar ratio and the concentration of given metallocene catalyst on the copolymerization processes and the structure and properties of its products have been studied. It has been found there exist an optimum reaction temperature about 50 ℃, at which polymerization activity reached maximum. Increase in catalyst concentration and Al/Zr molar ratio and decrease in BB1 amount can increase polymerization activity. Molecular weight of copolymer was decreased when temperature, Al/Zr molar ratio or catalyst concentration was increased. However, molecular weight of copolymer was increased when BB1 amount was increased. More BB1, less Al/Zr molar ratio, highertemperature or higher catalyst concentration would lead to high polar monomer ratio in copolymers. The melt temperature of copolymer was increased with the increase in either molecular weight or polar monomer ratio in copolymers..Copolymerization of propylene and BB1 have been also carried out using supported catalysts to avoid reactor foul. It has been found that effects of temperature, amount of added BB1, Al/Zr molar ratio and the concentration of catalyst on the copolymerization processes and the structure and properties of its products were similar to that found in homogeneous processes. Compared with the copolymer obtained with homogeneous catalyst, the one obtained with the supported catalysts has higher molecular weight, polar monomer ratio and melt temperature. However, the activities of supported catalysts were much lower than that of homogeneous catalyst.更多还原