气相色谱-质谱联用法鉴定硫化胶中促进剂

采用气相色谱-质谱联用法鉴定分析硫化胶中促进剂种类。结果表明,部分促进剂在橡胶硫化过程中发生了分解及重组反应,但通过其单体及反应产物的特征离子基本可以定性硫化胶所使用的促进剂种类,其中噻唑类和次磺酰胺类促进剂由于含有苯并噻唑碎片,当有次磺酰胺类促进剂存在时,不能确定该配方中是否含有促进剂M。     

GC-MS法分析两种辣蓼的脂肪酸成分

以湘西本地所采的两个品种的辣蓼为原料,通过对两种辣蓼的茎和叶分别进行索氏提取,再利用气相色谱-质谱联用仪分析鉴定其中的脂肪酸成分,研究不同种辣蓼的茎和叶部位的脂肪酸成分组成。因这两个品种的辣蓼在外观的颜色上有显著的差异,因此分别将它们命名为红辣蓼和白辣蓼来加以区分。结果共鉴定出10种脂肪酸成分结果表明:不同辣蓼所含有的脂肪酸成分有所区别,而同一种辣蓼的茎和叶所含脂肪酸的成分也是有区别的。     

GC-MS测定五类饮料中邻苯二甲酸酯类化合物

建立了15种邻苯二甲酸酯类化合物的气相色谱-质谱(GC-MS)分析方法,并将其应用于饮料样品的测定。在对检测条件进行优化的基础上,通过提取特征离子进行检测,得到15种目标物的线性范围为5～10000μg/L,方法的检出限(S/N=3)为3～500μg/L;考察了各类饮料的提取方法,并在100μg/L、10000μg/L两个加标水平下对方法的可靠性进行评价,平均回收率为90%～110%(n=6),相对标准偏差(RSD,n=6)为0.58%～4.90%。该方法灵敏度高、精密度好、前处理过程简单、溶剂用量小、净化效果好,可用于饮料中邻苯二甲酸酯的快速准确分析。     

GC-MS内标法测定己烷中的痕量苯

以丙酮为内标物,建立了一种气相色谱-质谱法测定己烷中痕量苯的方法.实验结果表明,在质量浓度为0.0006％～0.1808％之间,标准曲线的相关系数为0.9995,线性良好,相对标准偏差为1.02％(n=8),回收率在101.56％～103.22％之间,方法操作简单,检出限低,精密度好,准确度高.     

GC-MS法测定塑料产品中邻苯二甲酸酯类化合物

建立了塑料中邻苯二甲酸酯类化合物的气相色谱-质谱（GC-MS）测定方法.以四氢呋喃为萃取溶剂,用超声波萃取器塑料中的邻苯二甲酸酯类化合物,采用气相色谱-质谱联用仪（GC-MS）进行检测.邻苯二甲酸酯的线性相关系数r＞0.999,对实际加标样品的回收率在87％～110％之间,相对标准偏差（RSD）1.3％～4.8％,适合于塑料中邻苯二甲酸酯类化合物的测定.     

加速溶剂萃取GC-MS分析烟叶中香气成分

采用加速溶剂萃取提取烤烟烟叶中香气成分,并用气相色谱-质谱联用仪鉴定分析。采用标准谱库检索结合自动质谱退卷积定性系统鉴定,结果共鉴定出45种含量较高的香气成分,其中有18种酮、8种醇、8种醛、3种酯、2种酸、1种酚、4种其它类化合物和新植二烯等。结果显示加速溶剂萃取结合气相色谱-质谱联用仪可快速提取分析烟叶中主要香气成分。     

热脱附气相色谱-质谱联用鉴定硫化胶中促进剂种类

研究热脱附气相色谱-质谱联用进行硫化胶中常用促进剂的定性分析。结果表明:当特征反应产物仅有苯并噻唑基团时,可判定为促进剂MBT或MBTS;当除苯并噻唑基团外,还有对应促进剂反应产物中的其他基团时,可以判定次磺酰胺类促进剂的具体种类。该方法可直接分析硫化胶固体样品,有效避免促进剂特征产物的丢失,结果准确可靠。     

GC-MS结合化学计量学分析厚朴汤化学成分

利用气质联用技术(GC-MS)结合交互移动窗口因子分析法(AMWFA)比较分析了厚朴汤(药对厚朴-白术)及其单味药的共有成分,对药对与单味药的挥发油进行了定性和定量分析。鉴定出药对的挥发性组分62种,占总含量的91.60%;厚朴的挥发性组分54种,占总含量的90.43%;白术的挥发性成分53种,占总含量的91.83%。结果表明,厚朴与药对挥发油有35种共有组分,白术与药对挥发油有20种共有组分。药对挥发油成分并不等于两个单味药挥发油成分之和。     

硫化胶中促进剂NS定性检测方法的研究

通过对已知配方硫化橡胶的分析,建立高效液相色谱法定性检测硫化橡胶中促进剂NS的检测方法,结合气质分析确定促进剂在硫化橡胶中特征残留物质的结构。最后对已建立的检测方法进行了验证。     

Physical,mechanical, and viscoelastic properties of natural rubber vulcanizates cured with new binary accelerator system

Natural rubber was vulcanized with a new binary accelerator system based on 1‐phenyl‐2,4‐dithiobiuret (DTB) and dicyclohexyl benzothiazyl sulfenamide. A significant reduction in cure time was observed with the addition of DTB. The cure kinetics was investigated and the activation energy was determined. The mechanical properties were improved by adding DTB, and the maximum values are shown at an optimum concentration. Estimates of the concentration of crosslinks and of the relative proportions of different types of crosslinks were made by the chemical characterization of the vulcanizates. The crosslink densities obtained from swelling measurements and stress–strain measurements were compared with those obtained from modulus measurements. All of them follow a similar trend and support the observed mechanical properties. A dynamic mechanical analysis of the mixes was carried out and the activation energy was determined from Arrhenius plots. The glass‐transition temperature was found to increase with the increase in crosslink density and frequency of measurements. The stress–strain curves were found to not deviate from the strain crystallizing nature of natural rubber. The mechanical properties, network characterization, and processing characteristics were used to optimize the DTB concentration. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 2193–2203, 2003     

Controlled degradation of cured natural rubber by encapsulated benzophenone as a photosensitizer

The photodegradation of raw natural rubber and natural rubber compound film were studied using an artificial solar energy simulator. The properties of degraded rubber sheets containing benzophenone (BP) were determined by solution viscosity, ¹H‐NMR, and FTIR analyses. In the case of rubber compounds containing BP, the changes of tensile strength and crosslinking density were determined. It was found that BP could amply accelerate the photodegradation of rubber. To control the release rate of BP, it was necessary to encapsulate BP with urea–formaldehyde as a matrix. The encapsulated BP or capsule was formed by an interfacial polycondensation reaction between formaldehyde and urea. The kinetic of release rate of BP from urea–formaldehyde capsule was markedly observed within 15 days of release time; after that the rate of BP released from urea–formaldehyde microcapsule was very slow. At the same concentration of BP, the degradation rate of rubber compound by adding BP directly was faster than that of the rubber containing encapsulated BP. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 297–305, 2003     

用附着型促进剂制备橡胶/蒙脱土纳米复合材料

用附着型促进剂PBS在机械混炼插层法的基础上制备了天然橡胶/蒙脱土纳米复合材料。由于硫化后大部分促进剂基团都连在橡胶分子链上,因此用分子一端能和蒙脱土片层有相互作用的附着型硫化促进剂,可以大大增强蒙脱土和橡胶基体的相互作用,得到性能优良纳米复合材料。用PBS制备纳米复合材料其硫化体系活性能低,硫化胶交联密度增大,有机蒙脱土片层在橡胶基体中达到纳米级的分散,具有优良的力学性能,加入8%有机蒙脱土100%模量从1.2 MPa增至2.2 MPa,500%模量从8.12 MPa增至18.23 MPa,邵氏GA硬度从45增至55,而加入2%有机蒙脱土500%模量从8.12 MPa增至17.06 MPa,撕裂强度从36.31 kN/m增至43.65kN/m,加入2~10份有机蒙脱土时其效果相当于加入40份半补强炭黑。     

The behavior of dithiocarbimate derivative as safety accelerator of natural rubber compounds

A conventional vulcanization system containing tetrabutylammonium bis(4‐methylphenyldithiocarbimato)zincate(II) (ZNIBU) was used for curing of natural rubber (NR) compounds. Rheometric (t_s1, t₉₀, and CRI) and mechanical properties, such as tensile and tear strengths and modulus at 300%, were measured to evaluate the acceleration potential of ZNIBU. Commercial accelerators (TMTD, MBTS, and CBS) and a binary system CBS/ZNIBU were also tested for comparison purposes. It was observed that ZNIBU alone does not give either safe scorch time or cure rates appropriate for industrial applications. Nevertheless, mechanical properties are comparable to those given by the other accelerators used. As for the binary system, positive synergistic effects can be found in tear strength and modulus of NR vulcanizates. Besides, ZNIBU does not contribute for the formation of nitrosamines in the vulcanization process. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

双金属稀土促进剂对丁苯橡胶/天然橡胶胎面胶的影响

通过配位反应制备得到双金属硫化促进剂二乙基二硫代氨基甲酸锌镧配合物(ZnLaDC),在不添加传统活化体系氧化锌(ZnO)/硬脂酸(SA)的情况下,考察了ZnLaDC用量对丁苯橡胶(SBR)/天然橡胶(NR)胎面胶复合材料硫化特性及物理机械性能的影响,并与传统硫化体系二乙基二硫代氨基甲酸锌(ZnDC)/ZnO/SA制备的硫化胶性能进行了对比。结果表明,随着ZnLaDC用量的增加,SBR/NR胎面胶复合材料的硫化特性、压缩疲劳生热性能及耐磨性得到有效提高,当ZnLaDC用量为5份时,复合材料的综合性能最佳。与传统硫化体系ZnDC/ZnO/SA制备的硫化胶相比,采用ZnLaDC制备的硫化胶具有更优异的静态力学性能及耐切割性。     

低模量硫化硅橡胶粘接研究

采用sol—gel工艺自制的SiO2补强增韧环氧树脂作为胶粘剂,对低模量硫化硅橡胶与金属或复合材料进行粘接试验,分析胶粘剂中SiO2理论含量及粘接工艺对粘接性能的影响,并把硫化硅橡胶放在改性环氧树脂中进行溶张试验,探索胶粘剂对硅橡胶的粘接机理、结果表明,随着SiO2先驱体-有机硅烷含量的增加,硅橡胶的溶胀程度提高改性环氧树脂胶粘刺能浸入硅橡胶的表层,对硅橡胶具有良好的亲和力。用该胶粘剂对硅橡胶与金属或复合材料进行粘接时,取得了良好的粘接效果。     

吹脱-酸析-臭氧氧化预处理橡胶促进剂生产废水

采用吹脱-酸析-臭氧氧化工艺预处理橡胶促进剂废水,通过改变Na OH投加量、气液比、吹脱时间、p H值、曝气时间、臭氧投加量等,确定最佳反应条件,结果表明:对原水CODCr的质量浓度为12 000 mg/L的橡胶促进剂废水处理后,废水CODCr的总去除率为82%,作为蒸发除盐预处理,可以保障除盐装置的运行。     

绿色环保橡胶促进剂的配方研究

笔者研究了硫化促进荆M(2-巯基苯并噻唑)、促进剂CZ(N-环己基-2-苯并噻唑次磺酰胺)在橡胶制品中的应用，从经济环保的角度进行了新的配方设计，并进行了性能(邵尔A型硬度、抗拉强度、扯断伸长率和老化系数)测试。结果表明：同等条件下，生产相同的产品胶板，使用促进剂CZ的制品综合性能要优于使用促进剂M的制品，且用量少。     

橡胶促进剂NOBS废水处理工程实践

采用蒸发-催化氧化预处理橡胶促进剂NOBS废水,在进水COD≤20000mg/L情况下,预处理后COD约为1000mg/L.达到了预期处理效果。     

气相色谱-质谱/质谱联用法测定橡胶中的乙酰苯

建立了气相色谱-质谱/质谱联用法测定橡胶材料中乙酰苯的方法。样品用叔丁基甲醚超声提取,用气相色谱-质谱/质谱联用仪检测,该方法线性范围0.01～1.0μg/mL,相关系数r=0.9996,检出限0.1mg/kg,回收率为88%～102%。