Study On The Synthesis, Performance And Kinetics Of C₃₆ DFA Based Polyester And Its Derivant

Along with the global further spreading of sustainable developrnent stratagem, thesematerials, which come froln petrochemicals and were harmful to human being andnatural environment, will be gradually restricted in application, the mainlydevelopment trend in the modern material industry and chemical industry field is toexplore "the environmental friendly material" and "the green chemicals".In this paper, the synthesis, performance and kinetics of C₃₆ DFA (dimer fatty acid)based di-polyester or tri-polyester and its derivant, their polyesters were synthesizewith DFA and EG (ethylene glycol) or PEG (polyethylene glycol) and PPG(polypropylene glycol), were systemically and roundly studied. As the extending ofresearch work, at the same tirne rnanufacture process of DFA, synthesis and structurecharacterization as well as catalyzing performance of novel catalyst for dimerization offatty acid were studied, the research results were as follows:1. The dimerization reaction of the unsaturated fatty acid was catalyzed by a seriesof organ-intercalated montmorillomite, which was prepared by means of one ortwo-step intercalation. According to the research, it was found that organ-intercalatedmontmorillomite had better catalyzing activity and efficiency than montmorillomite indimerization reaction of the unsaturated fatty acid, and catalyzing activity oforgan-intercalated montmorillomite was influenced by kind and structure ofintercalating agent and CEC (cation exchange capacity). Catalyzing activity of organ-intercalated montmoriliomite had a positive linear relationship with its interlayerdistance on certain condition. The catalyzing activity and efficiency of organ-intercalated montmorillomite was linearly increased when interlayer distance wasraised from 1.26 mn to 2.19 nm, meanwhile yield and selectivity of DFA wereevidently increased. When CEC exceeded 40, catalyzing activity and efficiency oforgan- intercalated montmorillomite began to obviously decrease, the possible reasonwas that the active metal ions is littler in layers of organ-intercalated montmorillomite.Distribution performance of organ-intercalated montmorillomite was better thanmontmorillomite in reaction system. Stirring speed and consumption of energy can bedecreased in polyesterification reaction when the requirements for heat and masstransfer are fulfilled.A novel synthesis process of DFA under autogenous pressure was studied and developed with safflower oil fatty acid. The basic theory and operation method ofnovel process were as follows: certain water and fatty acid were added into thereaction system together, air containing oxygen was taken away from reactor byboiling vapor, and then the polyesterification reaction occurred at the collectivepressure produced by residual water and fatty acid. Comparing with the traditionalremoving oxygen process by pure nitrogen, novel technology can effectively reduceproduction costs, prevent catalyst losing activity and decrease secondary reaction, suchas decarboxylase, decompositiob and multi-polymerization, etc. at high temperature.The yield of DFA can be also increased.Amount of adding water had obviously influence on the yield of DFA in autogenouspressure process, the appropriate amount of water was 2.00ï¼…of total amount of DFA(w/w), too much or too little all affected the yield of DFA. Li₂CO₃ added in reactionsystem had well cooperative effect and assistant catalysis, could increase the yield andselectivity of DFA and get lighter color complex.3. The polyesterification reaction of DFA and EG was regarded as research object.The polyesterification reaction process of polyacid and polyalcohol was studied andimproved, and condition of synthesis reaction was determined. The improved processis as follows: the reactor was charged with nitrogen in the beginning, after certainreaction time the reactor was picked up suction in order to take away water producedin the course of reaction and elevates the reaction speed; water containing little EGwas separated with rectifier. The improved process could overcome the disadvantagesof the traditional process disadvantage such as long reaction time, consuming muchnitrogen, which was well used in synthesis of DFA-EG polyester.The kinetic of polyesterification reaction of DFA and EG was studied. The reactionsystem of polyesterification of DFA and EG was analyzed and simplified. Based on thehypothesis of equal and unequal activity of the end-group of monomer and polymer,the modelâ… and modelâ…¡for estimating kinetic parameters were established usingimproved Genetic Algorithm, which was so improved by introducing the Elitist Model,Simulate annealing, Runge-Kutta method, proportional distribution randomizer etc.into the operators, and these models were more compatible with the estimation ofcomplex reaction kinetic model parameters. A program for calculating the parametersof modelâ… and modelâ…¡was written with C⁺⁺ computer language. By comparison, itwas found that the kinetic model based unequal activity of end-group monomer andpolymer was more close to the fact and more accurately depict the polyesterification reaction of DFA and EG.By experiment, it was proved that the speed degree of polyesterification reaction ofDFA and EG was 2.0875 to carboxyl and 1 to hydroxyl respectively, and therelationship between average molecular weight and the inherent viscosity of DFA-EGpolyester was as follows: [η]=0.02696(?)0.7758 (25℃, taking cyclohexane as solvent)4. The preparation and performance of DFA based polyester resin were studied,which was prepared with DFA based unsaturated polyester, curing fixture and filler.The research results showed that the DFA based polyester resin had better mechanicalperformance, the water-fast performance, rate of elongation, flexility, the performanceof biodegradation and the burning-fast performance, but the chemical solvent-fastperformance, rigidity, tensile-strength were decreased.The experimental results of thermogravimetry analysis and differential thermalanalysis showed that the DFA based polyester resin had excellent thermal stability,decomposition temperature exceeded 370℃. It was completely decomposed around510℃, ratio of mass loss is 50.10ï¼…. The thermal stability and decompositiontemperature of the DFA based polyester resin was increased as the increase of theamount of DFA in the resin.5. DFA-PEG polyester was synthesized with DFA and PEG 400 at first, and then bysulfating DFA-PEG polyester with NH₂SO₃H or terminating DFA-EG polyester withrosin acid, two derivant, these are sulfated DFA-PEG polyester and terminateDFA-PEG polyester, were synthesized. The reaction conditions of synthesis wereoptimized by orthogonal experiments.The molecular weight of product was analyzed by GPC. The number averagemolecular weight of DFA-PEG polyester is 6135, and average weight molecularweight is 7798. Distribution of molecular weight is 1.212, and it is distributed innarrow range.DFA-PEG polyester and its derivant were novel macromolecule surface activityreagent, its molecule contains special structural hydrophilic and lipophilic group.Results of test showed that DFA-PEG polyester and its derivant had excellentemulsification performance, and emulsion was exquisite and steady, the surfacetension and critical micelle concentration (CMC) of DFA-PEG polyester and sulfatedDFA-PEG polyester were very low, DFA-PEG polyester terminated with rosin acid hadcertain antifoaming performance, but surface tension and CMC increase to extent. Thermodynamics and dynamics of polyesterification reaction of DFA and PEG 400were studied taking SnCl₂ as catalyst. The research results showed that the speeddegree of polyesterification reaction of DFA and PEG 400 was 0.998, activation energywas 97.18 kJ·mol^-1. Arrhenius equation is as follows: lnk=21.39-11.689/T.6. Synthetical regularity and applicable performance of DFA-PEG-PPG tripolymerpolyester synthesized with DFA, PEG 400 and PPG 2000 as reactant, DFA-PEG-PPGtripolymer polyester terminated with oleic acid, (DFA-PEG)_m-(DFA-PPG)_n blockcopolymer synthesized with DFA-PEG and DFA-PPG, were studied systemically. Atthe same time synthesis reaction conditions were optimized by orthogonal experiment.Activation energy of polyesterification reaction of DFA and PPG 2000 was108.4786 kJ·mol^-1. Arrhenius equation is as follows: lnk=25.166-13.043/T. As forthe tripolyesterification reaction, it is necessary to choose appropriate processconditions to control the yield and molecular structure of tripolymer polyester. Bycomparison, it was found that esterification rate of continuously adding reactant washigher than one-off adding reactant for synthesis of DFA-PEG-PPG tripolymerpolyester, distribution of molecular weight was narrower and number averagemolecular weight was larger.It was also found that the balance of hydrophilic and lipophilic of DFA-PEG-PPGtripolymer polyester macromolecule surface activity reagent was easily adjusted bychanging the adding amount of PPG. Terminated DFA-PEG-PPG tripolymer polyester,which was synthesis by adding long chain fatty acid or fatty alkanol into the reactionsystem, contained not only chain lipophilic group but also polyester-polyether group,and had the building effection of alkanol antifoaming reagent and polyether one. Thenovel design theory for structure of antifoaming reagent was put forward by studyingperformance of product. The molecular weight of (DFA-PEG)_m-(DFA-PPG)_n blockcopolymer synthesized with DFA-PEG and DFA-PPG was larger than the molecularweight of DFA-PEG polyester and tripolymer DFA-PEG-PPG polyester, theemulsification performance was better. At the same time it is easy to obtainwater-solubility or oil-solubility polyester macromolecule surface activity reagent.