Synthesis, Self-assembly And Application Of Comb-type Maleic Anhydride And α-olefin Copolymers

In winter, the temperature of northern China is very low, the long chain paraffins in diesel will be crystallized, which leads to plugging of the filter or even gelation. It brings a lot of difficulties for application and transportation of diesel. To solve this problem, comb-type maleic anhydride and a-olefin copolymers (MAC) were designed and synthesized, MAC could interact with long chain paraffins in diesel due to their special molecular structure and amphiphilic properties. Studying on the interaction of MAC with paraffins can help us to understand the mechanism of pour point depression, and to apply for preventing diesel from coagulation as well as improving its low-temperature flow ability. MAC are ideal crude oil pour point depressant which never be tried as diesel pour point depressant, this work is important and necessary for designing and synthesis of more efficient and relatively universal diesel pour point depressant.The main work was listed as the following three aspects.First, Comb-type (maleic acid alkylamides-co-a-olefin amide) copolymers (MAC) were prepared successfully in this research, various influencing factors and optimized reaction conditions of this polymerization reaction were studied, such as reaction temperature, time and dosage of initiator in order to get the optimization reaction condition. Influencing factors on polymerization molecular weight were mainly discussed, the results show that reduction of dosage and instantaneous concentration of initiator are good for getting a higher molecular weight polymer. However, when the temperature reached the reflux temperature of solvent, then temperature did not work for the change of molecular weight of polymerization products.Second, in this study, interaction of MAC with decane as solvent was studied by rheology and AFM. Results show that MAC can aggregate into inverse micelles with increasing of their weight concentrations in decane as nonpolar surroundings. The principle of inverse micelles water in oil formed is related to the hydrophilic association among carboxyl groups of MAC in nonpolar solvent.Third, MAC was employed as pour point depressants for model oil and Changqing crude oil. Moreover, it was firstly studied that MAC was used as diesel pour point depressants in order to improving low-temperature flow ability in this research, the effects on pour point depression were characterized by rheology. The effects of different prepared pour point depressants on the pour point of diesel, before and after diluted by 0# diesel, were evaluated by decreasing value of its pour point from rheological measurements. The best result for reducing pour point of 0# diesel indicated that:when adding of 0.3wt% prepared pour point depressant of MAC12-16 into 0# diesel, the pour point reduced by 6.8℃.