本体法ABS和乳液法ABS共混研究

将本体法丙烯腈-丁二烯-苯乙烯共聚物(ABS)和乳液法ABS共混,研究了共混体系的力学性能。结果表明:当本体法ABS质量分数为30%～50%时,共混体系的悬臂梁缺口冲击强度高于单组分的性能,与本体法ABS相比,增幅可达28%;拉伸强度和弯曲强度介于共混前2种ABS之间。动态力学研究表明,来自于2种工艺ABS中的苯乙烯-丙烯腈共聚物相容性良好。     

提高乳聚丁苯橡胶SBR1502的聚合转化率

以吉林石化公司丁苯橡胶1502为研究对象,以12 h内聚合转化率达到(70±2)%、产品性能与(62±2)%时相当为研究目标,首先考察了在标准配方条件下,提高丁苯橡胶聚合转化率对丁苯橡胶反应时间、生胶门尼粘度、结合苯乙烯含量、凝胶含量和胶乳粘度的影响,在此基础上系统研究了分子量调节剂(硫醇)总量、补加量和补加时机对生胶门尼粘度、凝胶含量的影响;电解质用量对胶乳粘度、生胶门尼粘度和聚合速率的影响;补加软水对聚合速率和胶乳粘度的影响;单体纯度对聚合速率的影响;乳化剂用量、乳化剂补加量对聚合速率的影响,并对比测定了不同转化率丁苯橡胶生胶和硫化胶的性能。研究结果表明,在不改变原材料品种和规格的前提下,经过聚合配方和工艺条件的调整,在12 h内可以使丁苯橡胶1502聚合转化率由(62±2)%提高到(70±2)%,并确保70%转化率丁苯橡胶的性能指标全部达到优级品标准。     

The thermo-oxidative decomposition,ignition and burning of flame-retarded polystyrenes

The theromo-oxidative decomposition, flash ignition and burning of high-impact polystyrene containing the flame-retardant system decabromodiphenyl oxide + antimony trioxide was investigated using the Setchkin apparatus combined with mass spectrometry. The time dependences of the release rate of the main products into the gas phase during decomposition and burning showed that the flame-retardants markedly influence these processes. It was found that the retardants used exhibit an acceleration of the polymer degradation and that the efficiency of inhibition in the gas phase depends on the atomic ratio antimony: bromine.     

New process stabilization system for emulsion polymerized ABS

In emulsion polymerized acrylonitrile-butadiene-styrene (ABS), an antioxidant system is added to the latex prior to coagulation. The antioxidant protects the polymer against the high temperatures encountered during drying and processing. Traditionally, hindered phenols have been used in combination with a co-stabilizer, such as tris-nonylphenylphosphite (TNPP) or dilaurylthiodipropionate (DLTDP). This paper discusses an antioxidant stabilization system based entirely on hindered phenol chemistry. This system provides excellent performance compared to the traditional systems without the presence of a phosphite or sulfur based costabilizer. In addition, the new antioxidant system is a liquid allowing for ease of emulsification and handling.     

国外乳液聚合丁苯橡胶技术进展

介绍了20世纪90年代国外乳液聚合丁苯橡胶制备、改性与延伸加工的技术进展。     

Semibatch anionic ring-opening polymerization of octamethylcyclotetrasiloxane in emulsion

The semibatch anionic ring-opening polymerization of octamethylcyclotetrasiloxane in emulsion was studied under the condition of no seed particles used in polymerization system. Concentration of emulsifier was set above critical micelle concentration. Effect of monomer feed rate on the chemical kinetics, average particle size and distribution and on the polymer molar mass and distribution was investigated. During monomer addition, polymerization rate was constant and controlled by the monomer feed rate. According to the proposed mechanism for anionic polymerization in emulsion, it was assumed that also the number of active polymerization sites and monomer concentration at the particle surface, where propagation occurs, remain constant. A continuous increase of average particle size and absence of extensive condensation reactions at high conversion suggested that the freshly added monomer diffuses toward hydrophobic polymer particles, where it is consumed in propagation reaction and/or accumulated in the particle core.     

聚氨酯/乳聚丁苯橡胶共沉胶的制备及性能

采用共沉法制备了聚氨酯/乳聚丁苯橡胶(ESBR)共沉胶,考察了芳香型和脂肪型聚氨酯的用量对聚氨酯/ESBR共沉胶性能的影响。结果表明,随着聚氨酯用量的增加,聚氨酯/ESBR共沉胶的门尼黏度下降,邵尔A硬度逐渐增加,扯断伸长率下降,300%定伸应力先增加后减小。与ESBR相比,加入聚氨酯后,共沉胶的焦烧时间、正硫化时间均显著下降,最小转矩增大;芳香型聚氨酯的加入可减小ESBR的压缩永久变形,有利于改善共沉胶的低温性能,当芳香型聚氨酯的用量为10份时,聚氨酯/ESBR共沉胶综合性能最佳。     

阴离子端羟基聚丁二烯的表征及其固化物的力学性能

简述了以硅烷保护羟基的烷基锂为引发剂,环己烷为溶剂合成丁羟胶的聚合方法;通过IR、^1H—NMR和GPC等方法研究了阴离子端羟基聚丁二烯主链结构、分子质量分布、官能度及其分布;对其固化物力学性能进行了评价。研究结果表明,阴离子端羟基聚丁二烯的1,4-结构含量高达约90％、分子质量分布指数≤1．05、官能度接近2,其固化物具有优异的力学性能。     

乳液聚合丁苯橡胶单体回收系统工艺技术改进

探讨了中国石油天然气股份有限公司兰州石化分公司乳液聚合丁苯橡胶装置单体回收系统化污水及胶乳中苯乙烯含量高的原因,以分析讨论为基础,对苯乙烯滗析器和汽提塔结构设计进行了优化改造,使控制指标达到设计值,从而解决了实际生产中存在的问题。     

提高乳聚丁苯橡胶SBR1502转化率工业化试验

吉林石化公司于2005年开展了提高乳聚丁苯橡胶SBR1502聚合转化率的研究,通过系统的实验研究,完成了小试技术开发,形成了70%转化率乳聚丁苯橡胶SBR1502小试新技术。2006年11月,根据70%转化率乳聚丁苯橡胶SBR1502小试技术成果,吉林石化公司对有机合成厂丁苯橡胶B、C线进行了技术改造,并在C线上进行了提高乳聚丁苯橡胶SBR1502聚合转化率工业化试验。工业化试验表明,70%转化率SBR1502生产运行平稳,聚合转化率达到预定的（70±2）%,聚合时间在10～11h,产品质量经有机合成厂分析车间检测全部达到了优等品标准,取得了大生产试验的成功,形成了70%转化率丁苯橡胶SBR1502生产新技术。     

高内相乳液聚合制备多孔整体聚合物的孔结构调控与表征

以苯乙烯、二乙烯基苯为原料,山梨糖醇酐单油酸酯Span80为乳化剂,过氧化苯甲酰(BPO)为引发剂,氯化钙水溶液为分散相,通过高内相W/O乳液体系制备Poly HIPE。探讨了不同油水比、乳化剂用量和二乙烯基苯含量对聚苯乙烯(PS)/二乙烯基苯DVB型Poly HIPE孔结构、密度和比表面积的影响。结果表明,随着油水比的减小,乳液稳定性增强,Poly HIPE孔径变大,贯通孔数量增多;增加乳化剂用量或单体中二乙烯基苯比例,Poly HIPE的孔径变小,贯通孔数量增多。除此之外,研究还发现油水比的减小使得Poly HIPE的表观密度和比表面积降低,而提高乳化剂用量和二乙烯基苯比例可提高Poly HIPE的表观密度和比表面积。     

Thermal conductivity of suspension and emulsion materials

A technique for the prediction of effective thermal conductivity of porous materials previously developed by the authors has been extended to suspension and emulsion systems and its capability is supported by the available experimental data. A nomogram which estimates the effective thermal conductivity for these systems from the knowledge of constituent conductivities and proportions is also provided.     

Thermal variation of the apparent specific volume of polystyrenes in solution

A new approach to the polymer interactions inside and outside the coil is discussed and we explain the experimental variation of the apparent specific volume of polystyrene in good and in θ-solvents. In cyclohexane we define two very different regions above and below the θ-point. For the region above the θ point we calculate the thermal dilation coefficient, $\text{}\text{?}$ga, subtracting the intramolecular segment density effect. We relate $\text{}\text{?}$ga to the external degrees of freedom of the chain starting from the Prigogine theory of polymer solutions. We first considered the intramolecular segment interactions of the coil in the dilute solution.     

提高转化率对乳聚丁苯橡胶性能的影响

以吉林石化公司有机合成厂的乳聚丁苯橡胶(SBR)生产配方为标准配方,研究了聚合反应时间对转化率的影响,分析了提高转化率对SBR的生胶门尼黏度、结合苯乙烯含量、凝胶含量、相对分子质量及其分布、胶乳黏度等基本性能的影响。结果表明,在标准配方条件下,延长聚合反应时间,转化率可以达到70%。转化率为70%时所得SBR与转化率为62%时所得SBR相比,前者的生胶凝胶含量和胶乳黏度均增大了1倍,数均相对分子质量、重均相对分子质量和Z均相对分子质量均高于后者,相对分子质量分布变宽,且前者的生胶结合苯乙烯含量能够达到产品标准,而生胶门尼黏度和在50 m in时的300%定伸应力偏高于产品优级品要求。     

Thermal decomposition of asphaltenes

The thermal decomposition of Athabasca asphaltene at relatively low (< 350 °C) temperatures is believed to proceed by elimination of groups situated on peripheral sites of the asphaltene. More severe degradation of the asphaltene structure does not occur until elevated (> 350 °C) temperatures are attained.     

Thermal decomposition of polystyrene

Kinetic studies on the decomposition of polystyrene samples with molecular weights ranging from 900 to 1.8 × 10⁶ have been carried out making use of the differential thermogravimetric and differential scanning calorimetric techniques. Changes in molecular weight distributions with decomposition, at different temperatures or times, have been studied by gel permeation chromatography. This technique was likewise used to carry out component splitting of the undecomposed polymer samples. These components have been shown to break down statistically primarily by a process of random scissions yielding lower molecular weight products. The major portion of the observed weight loss, by the volatilization of small chain segments, is attributed to a rapid and complete depolymerization of chains. These interpretations are based on changes in polydispersity occurring during the decompositions. Similar components, decomposing in a different manner but under identical operating conditions, are suspected of being different stereoregular forms of the polymer. The order of reaction as computed from the method of Freeman and Carroll has been found to be zero for random scissions and one for the process of depolymerization. The activation energy computed by the method of Coats and Redfern was found to increase with molecular weight reaching a maximum value in the 10⁵ molecular weight range.     

Thermal decomposition of tricaproin

Tricaproin was used as model system to study thermal decomposition of simple triglycerides. The tricaproin samples were pyrolyzed under three different conditions: at 250 C for 1 hr, 270 C for 1 hr and 270 C for 15 hr. Hydrocarbons, acrolein, methyl hexanoate, hexanal, hexanoic acid, 6-undecanone, 2-oxoheptyl hexanoate, propanediol dicaproate, propenediol dicaproate, oxopropanediol dicaproate and dicaproin were identified. Mechanisms involving both free radical and nonfree radical reactions were proposed for the formation of these compounds.