Study On Synthesis And Micellization Of Amphiphilic Comb Polymers

Abstract Amphiphilic polymer is a molecule containing both hydrophilic and hydrophobic groups. Two groups are mutually exclusive, in a selective solvent, amphiphilic polymers have many special properties, these properties have been paid a lot of attention, many research results have also been put to use. Amphiphilic comb polymer chemistry in recent years is a hot research topic, comb-type structure which impact to the self-assembly of amphiphilic polymers is received wide attention. But in recent years research in this area always focus on precisely controlled structure of amphiphilic comb polymer, such as amphiphilic block copolymers prepared by atom transfer radical polymerization (ATRP) or reversible addition-fragmentation chain transfer (RAFT) polymerization methods. Random comb-type copolymers are difficult to control structure, so they are often considered difficult to accurately explain the law. But in the application of the technical level, random copolymer of the production costs are far lower than the controlled polymerization products, so the designs of amphiphilic comb polymer which can be applied to the application of a technology become the research goal of this paper.The concept self-assembly that is from the beginning of life science, a single biological molecule is self-organized into a special structure. From chemical point of view, molecular self-assembly is through non-covalent bond formatting thermo dynamically stable structure; this process is a clear order of aggregation. Through self-assembly, molecular crystals can be obtained, also liquid crystal, colloids, micelles, emulsions, phase polymer and Langmuir-Blodgett film. Obtained by self-assembly of new functional materials, the field of chemistry has been widespread concerned. Amphiphilic comb polymer micelles was prepared by the self-assembly mechanism.This paper is divided into three parts:Firstly, amphiphilic polymers and comb polymers were introduced, as well as micelles research progress. Variety of forms could be self-assemble together to forma, so it was attracted wide attention in polymer science. Comb structure has a better ability in amphiphilic polymers self-assembly, through the control of the polymer structure; more extensive self-assembled structures could be prepared. Therefore, amphiphilic comb polymers in oilfield has also been widespread concerned in the design and conduct of all subjects on this basis;Secondly, the amphiphilic comb polymer preparation process was shown. The solution polymerization method was used. Using a variety of pro-big oleophilic monomer (for example, long chain alkyl acryl ate) and a variety of small hydrophilic monomer (e.g. propylene acid derivatives), a series of polymers with amphiphilic, comb-type structures were synthesized by copolymerization.' Better micellization capabilities which two micelles:P (LMA-MA) and P (AA-MMA-LMA) were chosen, Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (1H-NMR), infiltration Gel Permeation Chromatography (GPC) and other means were used to detect the structure of the polymer. It was characterized to prove that the molecular weight of polymer products were down 100 thousands with comb-type structure, and contained a long alkyl side chains and hydrophilic groups of the polymers;Lastly, P (LMA-MA) was putted into selective solvent (water) to prepare amphiphilic comb polymer micelles to research the amphiphilic comb polymer micelles. The amphiphilic comb polymer micelles were characterized by Zeta potential of particle size analyzer and transmission electron microscopy (TEM). By calculating the micelle size and side chain length, that the hollow spherical micelles were prepared, the conclusion was confirmed TEM results. By changing the concentration, temperature and pH and other factors were changed to observe that the amphiphilic comb polymer micelles of environmental response, it is observed that in a certain range of temperature and pH value, size and state of the amphiphilic comb polymer micelle does not change, that is, temperature and pH stability of the amphiphilic comb polymer micelles was shown. The micelle solution with placing a period of time (more than three days) is test by TEM. the results showed that the micelle aggregation occurred; the micelle aggregation with spherical shell structure was still present.Comprehensive paper work and test results, the conclusion was reached:in this article, a series of polymers were prepared by solution polymerization, according to the ability to form micelles, target polymers were chosen. This measured molecular weight of the polymers was about 100 thousand, both hydrophilic and hydrophobic groups were in the molecule, and they had a long alkyl side chain and comb-type structure. Micelles were formatted when the amphiphilic comb polymer P (LMA-MA) putted in the selective solvent (water), CMC of the polymer micelle concentration in water is about 250-300ppm. These micelles have large size (200nm and above), hollow structure of the micelles were known by calculation, in a certain range, temperature, pH stability of the micelles were characterized. After a certain period of time the aggregation occurred, but core-shell structure was still present. These properties were consistent with previously described purpose of the synthesis, that is, these properties were beneficial to format micelles to get rid of residues of crude oil.