Study On The Process For Making Light And Colorless Pinene Resin And Its Property

Pinene resin are used in numerous fields of application because of theirversatile properties. They are seldom used alone but mainly in conjunction withother materials to adapt their properties to special requirements. The mostimportant applications are in adhesives (construction, solvent- or water-based,hot-melt and pressure-sensitive adhesives), tackifiers, coatings (paints,varnishes, roadmaking), the rubber and plastics industry (mainly mechanicalrubber goods and tires), printing inks, and, to a lesser extent, in various otherindustrial fields. Nevertheless, the procedure to produce the pinene resinshowed a lot of disadvantages, such as, the weight ratio of catalyst to monomerwas more than 6.0%, Gardner grade (Fe-Co) of pinene resin was more than 5,Softening point (RB) was less than 130℃, the productivity was less than 80%and so on. At the same time, the study on the process for making light color andcolorless pinene resin and its properties had not been focused on until now.Sources of naval stores are rich and pine resin are the main ended products inChina, if a new process for making pinene resin with light and colorless andhight soft point could be set down, which will improve the property of pineneresin, as a result, it will elevate the value and extend its uses to acceleratedevelopment of naval stores industry in our country.In this dissertation,α-pinene and/orβ-pinene distilled from turpentine andan initiatior coming from the binary AlCl₃/SbCl₃ were employed, in the view of the mechanism for pinene cation polymerization, pinene resins with light colorand colorless and high soft point were made by the method improving of theprocedure and parameters of cationic polymerization , which were going tocontrol the reactivity ofα-pinene and/orβ-pinene respectively and inproportion to the velocity of chain initiation and propagation and termination.The pinene resins were characterized by solubility power, soft point (RB),GPC, ozonization, UV, IR and ¹³C-NMR, TG and so on. Its photo-stability,thermoxidative stability and kinetics of thermolysis were studied also, and someequations relation to the color and the kinetic parameters were estimated fromthe result. The main contents and conclusions in this dissertation were asfollows:1. A new optimized process with simple operation to make light color and highsoft point pinene resin was provided, the optimum conditions ofpolymerization were set down, namely, Polymerization temperature -15℃,during the first step polymerization, dropping rate ofα-pinene 4.0mL/min,dropping rate of SbCl₃ 4.0mL/min, w(AlCl₃/α-pinene) was 1.0%,m(SbCl₃)/m(AlCl₃)=1.0; during the second step polymerization, dropping rateof SbCl₃ 2.0mL/min, w(AlCl₃/α-pinene)=2.0%, m(SbCl₃)/m(AlCl₃)=1.0,interval time between the first and the second step polymerization 0.5h,holding time 2～3h.α-Pinene resin with softening point (RB) 138.0℃, yieldmore than 81.0% and Gardner grade(Fe-Co)3, acid number(mgKOH/g)0.85and saponification number(mgKOH/g)1.0 was obtained under the optimumconditions, at the same time, more than 20% amounts of adding initiatior wasreduced, the resins' softening point was 8℃higher and Gardner grade was 2lower than that by traditional methods, and the characterized parameterexceed the best grade by standardized method LY/T1453-1999 also.2. A new approach and process were found to make colorless alpha-pinene resinfrom alpha-pinene, as follows:The first step was to make pre-polymer with light color, the process wasjust as the same as making light and high soft point pinene resin except thestage of distillation, at this stage a agent was put in, which could prevent the resin's color becoming dark, the best operation parameter in this stage was asfollows: w(PS-10/resin)=0.3%, temperature 160℃, holding time 0.5h。The second step was to dismiss the double bonds by the catalytichydrogenation of resins, the best operation parameter were as follows:temperature 240℃, pressure 6.0MPa, w((Pd/C)/resin)=0.6%, holding time1.0h, stirring speed 600rpm。3. The process of making light and high soft point alpha/beta-pinene resin wasstudied, the best operation parameters were as follows:polymerization temperature 0℃, m(α-pinene): m(β-pinene)=7:3,dropping rate ofα-pinene andβ-pinene and SbCl₃ were 4.0 mL/min,w(AlCl₃/α-pinene)=3.0%, m(SbCl₃): m(AlCl₃)=0.50, holding time 3～4 h,andα/β-pinene resin with softening point(RB) 136.0℃, yield more than84.0%, Gardner grade (Fe-Co) 3, acid number (mgKOH/g) 0.82 andsaponification number (mgKOH/g)0.98 was obtained, at the same time, morethan 25% amounts of adding cocatalysts was reduced, the resins' softeningpoint was 8℃higher and the color grade was 2 lower than that bytraditional methods, and the characterized parameter exceed the best grade bystandardized method LY/T 1453-1999 also.4. It was discovered that the alpha/beta-pinene resin made by the optimumconditions just stated in 3 above was not a mixture of alpha-pinene resin andbeta-pinene resin but a copolymer, the recurring unit in the final polymerchain would be5. The high-quality light and colorless pinene resins are characterized andanalyzed.6. The properties of high-quality light and colorless pinene resins were studied.It were showed that: (1) the law of the color changing after the resin beingexposure to the UV light and heated were discovered, and the fit equationcorresponding to color varying were set down, which showed quantitativelythe resin photo-stability and thermoxidative stability. (2) After the resin wereexposure to the UV light and heated at temperature above the soft point of the resin, the chain ends with benzene and the double bonds inside the ring of(?) were broken down, and part of minor molecular were formed andescaped at the same time, also some new substance with(?)group wereformed. There some different among the structure in the resin which weretreated with heat in different temperature and environment.7. The heated decompose kinetic equation for high-quality light and colorlesspinene resins were deduced in different conditions and the correspondedkinetic parameters were set down also.