以NS616为对比样,对两种使用不同官能化引发剂的SSBR进行结构与性能对比测试.表明三种牌号的官能化SSBR均属于中苯高乙烯基产品,且结构单元质量分数和数均相对分子质量大致相同,SSBR-A与NS616为星型结构,SSBR-B为线型结构;三种样品中,星型NS616样品的加工性能较好、Panye效应较低、抗湿滑性和滚动阻力更加优异,SSBR-B次之.星型SSBR-A样品中引入强极性官能团,加工性能最差,仅Panye效应优于样品SSBR-B.

对溶聚丁苯橡胶(SSBR)72612 S及自制的2#SSBR样品进行了结构剖析,研究了星形偶联结构与性能的关系.结果表明,SSBR 72612 S和2#SSBR样品均为星形高乙烯基含量SSBR,均具有较好的力学性能和老化性能,产品与炭黑结合较好.其中,SSBR 72612 S表现出较好的生热性能和回弹性,同时具有较好的抗湿滑性能和加工性能及低滚动阻力.

In this paper,the effects of factors (including initiator,activator,coupling agent, impurity content in raw materials etc.)on the property of SBS were investigated.The inner quality of SBS produced by different producers were analyzed and evaluated by means of gel permeation chroma-tography(GPC)data analyzing and GPC curve directly comparison.The differences of the inner quality of SBS were found.The technique measures for controlling and improving the inner quality of products were proposed as follows:Initiated polymerization temperature is controlled at 42 ℃,the highest tem-perature is about 105 ℃,mass fraction of tetrahydrofuran (THF)is 5×10﹣5~1×10﹣4;mass fraction of water in solvent is not greater than 1×10﹣5;after downtime,according to the analysis of products GPC,timely adj usting the dosage of initiator and coupling agent,finally,realized smoothly industrialized production of SBS.

The basic properties and structures of SSBRs,2564S,2557S,2557TH,and 72612S,produced by Dushanzi Petrochemical Company of PetroChina were evaluated and compared.The results showed that all the products had high vinyl contents and exhibited good processing properties.The products displayed good bonding property with carbon black,and the SSBR vulcanizates exhibited good mechanical properties,aging resistance,wet skid resistance,and low rolling resistance.

考察不同混炼设备、混炼工艺方法(填充系数、转子转速、上顶栓压力等)对胶料混合效果、门尼黏度及硫化胶性能的影响,优选出适用于天利公司实业稀土异戊橡胶产品的混炼方法.

The apparent viscosities of systems of NdBR and NiBR-toluene were determined by using DV-Ⅱ+Pro viscometer under different conditions in which concentration was 8%~12wt%,and temperature was 30~70 ℃.Results indicated that(1) flow activation energy(ΔEη)of systems of NdBR is less than NiBR under the same shear rate(γ),and ΔEη of systems of NdBR and NiBR tends to constant values under γ is more than 30 s-1.They are 5.5 and 6.8 kJ/mol,respectively;(2)temperature and concentration have no effect on the flow index(n)of NdBR system.The value of n is about 0.77,which is belong to a typical pseudo-plastic fluid;(3)the value of concentration effecting index β is between 4.497 and 4.882 as the concentration is 8%~10%,and the value is between 7.239 and 7.498 as the concentration is more than 10%.So the critical concentration turning from solution to melt is 10%.For NiBR system the β is 5.645 at 8%~12wt%,belonging to melt.

Inverse gas chromatography technology was applied to characterize the surface properties of cis-1,4-polybutadiene rubber synthesized by using neodymium catalyst.The dispersive components of free energy of two rubbers were 47.18,46.61,46.16,45.99 and 45.60 mJ/m2,47.12,46.25,45.81,45.65 and 44.83 mJ/m2 at 30 ℃,40 ℃,50 ℃,60 ℃ and 70 ℃,respectively.The results indicated that the Lewis acidic number ka of the rubbers was 0.35 and basic number kb was 1.8.This meant that the material was weak basic Lewis amphoteric polymer.

The neodymium based cis-1,4-polybutadiene rubber catalyzed(NdBR)-toluene solution was prepared.The effects of the three factors of mass fraction of NdBR rubber in toluene(C),temperature(T) and shear rate(γ) on the apparent viscosity(η) of the rubber solution were studied,and the fluid constant(a) and zero shear viscosity(η0) were examined by extrapolation method.The results showed that the influence sequence of the three factors on η was C≥γ≈T.The regression equation were ln η=0.815 2+3.533 5 ln C+13.405 4/T-0.210 8 ln γ at C of 8.00%-10.00%,γ of 4.40-25.00 s-1;and ln η=-6.593 7+6.751 9 ln C+13.466 9/T-0.212 0 ln γ at C of 10.00%-12.00%,γ of 0.88-15.00 s-1.The appropriate T of the two regression equation were all 30-70 ℃.The a=0.000 635,and the empirical equations of η0 was ln η0=-5.674 2+6.464 4 ln C+12.289 2/T,and the sequence of influencing η0 for the two factors was C≥T.

The determination of neodymium content in the wastewater from production of RE cis-1,4-polybutadiene rubber in pilot-scale by absorption spectrometry was studied.The determination conditions were as follows:the maximum absorption wavelength was 674 nm;Nd3+ standard solution,CPAⅢ and buffer solution were added in turn,upper limit ofρ(Nd3+) was 2.0 mg/L,dosage of 0.500 g/L CPAⅢ anhydrous ethanol solution was 3.0 mL and pH was 2.0,dosage of hydrochloric acid-glycin buffer solution was 9.0 mL.The slope of standard curve was 0.428 2,the recovery of standard curve was in the range of 97.5%～102.4%,which can meet the requirement that measurement error was not more than ±5%.The metal element analysis was carried out by ICP-AES,concentration of calcium was 10.85 mg/L.The correction equation of determining neodymium was regressed by Origin under 0～20 mg/L calcium co-exist.Then,the determined concentration of neodymium in the waste water was 3.35 mg/L,whose concentration was in the micro-level.

Stability of chlorophosphonazo Ⅲ as a chromogenic reagent for determination of Nd by spectrophotometry was studied by tracking the change of the absorbency and the slope of the standard curve every two days during 62 days.Results indicate the standard curve is stable basicaly because fluctuation intensity is LT 3%.So if precision requirement of measurement is lower,k is 0.4345.Otherwise duration of the chromogenic reagent is LE 30 days,and k is 0.4260.

Inverse gas chromatography was applied to the characterization of the surface properties of polybutadiene rubber (PBR). Four n-alkanes (C6, C7, C8 and C9-alkanes) were chosen as the apolar probes to characterize the dispersive component of surface free energy. Dichloromethane, trichloromethane, acetone, ethyl acetate, diethylether and tetrahydrofuran were chosen as the polar probes to detect the Lewis acid-base parameters. It was found that the dispersive components of surface free energy were 47.07, 46.46, 45.85, 45.60 and 45.09 mJ/m2 at 303, 313, 323, 333 and 343 K, respectively. The results showed that the surface free energy decreased linearly with the increase of temperature. The Lewise acidic number Ka of PBR was 0.34, and the basic number Kb was 1.77. The fact Kb/Ka >1 means that the surface of PBR was amphoteric with dominant basic character and the total ability of the surface to acid-base interactions was 2.11. The free energies of adsorption -deltaG(a)s and -deltaH(a)s by Lewis acid-base interaction were also figured out.

Uniform design method was used to design SBR/NR/BR radial ply tire crown formula with NdBR,carbon black and silica.Stepwise regression analysis of main physical and mechanical properties of vulcanizate was carried out with SAS regression analysis software,regression equation of properties and main influence factors was obtains,then the regression equation was verified and the formula was improved with its guidance.The results show that the regression equation can predict the vulcanizate’s properties of the system very well,and guide to improve the vulcaniz ate formula.

Intrinsic viscosity([η]) of the rare earth-based cis-1,4-polybutadiene rubber(NdBR) produced by pilot plant of Institute of Dushanzi Petrochemical Company was determinated with viscometry,that was extrapolation method or one-point method.The influences of temperature and initial concentration of NdBR on [η] was studied.The viscosity-average molecular mass of NdBR was finally calculated by the Mark-Houwink equation and compared with nickel-based cis-1,4-polybutadiene(NiBR).The results showed that the viscosity-average molecular mass of NdBR was between 28.0×104～34.3×104,which was higher than that of NiBR(24.6×104).One-point method used in determining [η] of NdBR was more simple and quick than extrapolation method.The relative error of the two methods was less than 4.0%.So one-point method could replace extrapolation method to determine the viscosity-average molecular mass of NdBR.

The carbon number distribution of n-paraffins in three 0# diesel fuels from Lanzhou petrochemical company,Daqing petrochemical company and Geermu refinery,respectively,and their cold filter plugging points(CFPP) before and after addition of pour point depressant(PPD) were determined.The wax crystal morphology in these diesel fuels was observed before and after addition of PPD with a transmission electron microscopy.The results showed that the wax crystal size was above 200 nm in the diesel fuel containing PPD.If the wax crystal size could be reduced under 100 nm by PPD,the CFPP would be remarkable decreased,otherwise,the PPD would be useless,which was the reason to cause different CFPP decreases for different diesel fuels.

The iron-based high syndiotactic 1,2-polybutadiene was synthesized. The characterization of molecular structure and the evaluation of basic performance of the synthesized product were carried out and compared with RB series by Japan Synthetic Rubber Co. The results showed that the catalyst system had a higher activity,the polymerization product had a higher yield and exhibited a lower melting point(lower than 130 ℃) and a great tensile strength(20 MPa).

Crystallization of wax from diesel fuels and the interaction of pour point depressant with wax were studied by solid liquid equilibrium method.The solid phase and liquid phase of partially frozen diesel fuels were separated at the cold filter plugging point by isothermal filtration using a cold filter plugging point tester and were analyzed by gas chromatography.The amount and compositions of both phases were deduced from mass balance after correction by a distribution factor Z(the mass fraction of liquid in solid deposit).Four kinds of fuels were used to test including model fuel,model fuel with depressant,base diesel fuel and diesel fuel with depressant,and their crystallization rate and the content of n-paraffin in wax at cold filter plugging point were compared.Results showed that using said separation technique and calculation method to study the crystallization behavior of diesel fuels at cold filter plugging point was feasible.

The effects of several copolymers with different molecular structure as pour-point depressant in diesel fuel and synergism of their blend were investigated.The results showed the nucleation ability,the dispersion performance and the synergism of the copolymers were mainly affected by their molecular structures.The analytical results of transmission electron microscope(TEM) showed that ethylene-vinyl acetate copolymer(EVA) had a better nucleation ability and MC14-MA-MCNR1R2 possessed an excellent dispersion performance.Using their blends,both the pour-point and the cold filter plugging point of diesel fuel were depressed to a satisfactory extent,and the wax crystal particles dispersed uniformly and went smaller.The particles size of 95% ranged from 30 nm to 40 nm.The method of freezing etch in TEM observation was a good way for the research on wax crystal conformation and the mechanism of inter-reaction between pour-point depressant and wax crystal.