GC-MS法测定塑胶跑道材料中游离TDI的研究

建立了超声萃取结合气相色谱-质谱(GC-MS)联用的方法检测聚氨酯塑胶跑道材料中游离甲苯二异氰酸酯(TDI)的含量,并对新建操场的材料质量进行了评价。结果表明,塑胶跑道材料中游离的TDI均为2,4-TDI,相对标准偏差不超过2%,样品的加标回收率在89.85%~95.95%之间,说明该方法可以用于检测塑胶跑道材料中游离的TDI。对本实验所采集的样品的检测结果显示,TDI的含量没有超过GB/T 14833—2011《合成材料跑道面层》中规定的0.2 g/kg的标准。     

气相色谱-质谱联用技术检测合成聚氨酯黏合剂原料中6种有毒有害物质

采用气相色谱-质谱联用法(GC-MS)检测合成聚氨酯黏合剂原料中的2,4-甲苯二异氰酸酯(2,4-TDI)、三乙酸甘油酯(GTA)、邻甲苯胺(o-T)、4-氨基联苯(4-ABP)、2,6-二氨基甲苯(2,6-TDA)以及4-叔丁基苯酚(4-TB)。聚氨酯黏合剂原料用二氯甲烷作溶剂,经超声萃取,离心分离上机。用GC-MS全扫描定性,选择离子定量。各种物质在浓度为0.05~5.00 mg/L的范围内线性关系良好,相关系数R0.996 7;样品加标回收,添加浓度为0.10、0.20、0.40 mg/kg的加标回收率为74.0%~120.1%,相对标准偏差RSD(n=6)为3.6%~6.1%;仪器检出限的范围在0.1~8.0μg/L。该方法在17 min内完成了对6种物质的分离和检测,结果准确,重现性好。并应用该方法测定了合成聚氨脂黏合剂原料中含有的该6种物质。     

固化剂中游离MDI的高效液相色谱分析

建立了反相高效液相色谱法测定固化剂中游离MDI含量的方法。以异丙醇为衍生剂进行柱前衍生化,选用Waters XTerra C18,5μm,3.9mm×150mm色谱柱,乙腈—水为流动相,V(乙腈)∶V(水)=50∶50,检测波长为254nm。在5～50μg/mL范围内,4,4'-MDI、2,4'-MDI的回归方程相关系数均大于0.999,固化剂中4,4'-MDI、2,4'-MDI添加回收率在102.3%～109.9%。按样品测定方法平行测定5次,2,4'-MDI、4,4'-MDI峰面积的相对标准偏差(RSD)分别为0.74%、0.49%。该法测定固化剂中游离MDI具有良好的准确性和精密度。     

一种未知胶粘剂的化学成分检测方法研究

运用傅里叶红外分光光度计结合GC-MS(气相色谱-质谱联用仪)对未知胶粘剂进行了定性分析,得到未知物的组分别是2,2’-MDI(二苯基甲烷二异氰酸酯)、2,4’-MDI、4,4’-MDI和少量MDI二聚体。研究结果表明:4,4’-MDI在1.01～10.10μg/mL浓度范围内的线性关系良好;采用GC-MS外标法测定得出未知胶粘剂中4,4’-MDI的含量是44.72 mg/mL;利用面积归一化推算出未知胶粘剂中2,4’-MDI和2,2’-MDI的含量分别为52.54、2.14 mg/mL。     

GC-MS法测定塑胶跑道面层非固体原料中16种有机物含量

建立了塑胶跑道面层非固体原料中16种有机物(包括:二氯甲烷、三氯甲烷、四氯化碳、苯及苯系物等)含量的气相色谱-质谱联用(GC-MS)检测方法,优化了气相色谱和质谱参数,讨论了不同溶剂对16种有机物回收率的影响。研究结果表明:16种有机物在0.5～50.0 mg/L浓度范围内呈线性关系,相关系数均大于0.999,方法检出限范围为1.0～5.0 mg/kg,定量限为5.0～15.0 mg/kg;低、中、高三个浓度添加标水平下的平均回收率在81.3%～107.3%之间,相对标准偏差(n=6)小于7.6%。该方法快速、准确、灵敏,适用于塑胶跑道面层非固体原料中16种有机物含量的检测。     

GC-MS法测定塑料玩具中6种塑化剂的含量

建立了气相色谱-质谱法(GC-MS)测定塑料玩具中6种塑化剂的分析技术。样品经二氯甲烷超声萃取,经DB-5MS分离,采用GC-MS进行定性和定量分析。结果表明:在0.5~10.0mg/L的线性范围内,6种塑化剂的线性关系良好,相关系数(R~2)均不低于0.999,检出限为0.13~0.25mg/kg,加标回收率为89.7%~101.5%,相对标准偏差为0.8%~3.9%。该法简便快速、准确度高、检出限低,可为塑料玩具中塑化剂检测提供技术支持。     

采煤机械油缸密封材料用聚氨酯弹性体的研究

以聚四氢呋喃二醇(PTMG)和聚己内酯二醇(PCL)为软段原料,2,4-甲苯二异氰酸酯(2,4-TDI)、4,4'-二苯基甲烷二异氰酸酯(MDI)、3,3'-二氯-4,4'-二氨基二苯基甲烷(MOCA)和1,4-丁二醇(BDO)为硬段原料,采用预聚体法合成3种聚氨酯弹性体材料,研究了不同类型的聚氨酯弹性体的物理机械性能、高温物理机械性能以及耐乳化液性能。结果表明,聚氨酯弹性体PTMG-MDI-BDO和PCL-MDI-BDO的常温物理机械性能优于PTMG-TDI-MOCA; PTMG-TDI-MOCA在80℃和100℃下的高温物理机械性能优于PTMG-MDI-BDO和PCL-MDI-BDO;含MDI-BDO硬段的聚氨酯弹性体耐85℃水乳化液性能优于含TDI-MOCA硬段的。PCL-MDI-BDO是3种聚氨酯弹性体中最适合用作采煤机械液压支护设备油缸密封件的材料。     

聚氨酯弹性体改性双马来酰亚胺树脂的研究

本文研究了聚醚-甲苯二异氰酸酯(TDI)对4,4'-二苯甲烷一双马来酰亚胺(BMI)/3,3'-二氯-4,4'-二胺基二苯基甲烷(MOCA)的增韧作用.内容包括:聚醚-TDI的含量对固化树脂力学性能、热性能的影响,分析了改性BMI/MOCA体系的固化反应机理,研究了MOCA扩链BMI的配方、反应性,确定了聚醚-TDI对BMI/MOCA树脂的改性配方及固化工艺.     

GC-MS法测定塑料中对特辛基苯酚残留量

建立了用气相色谱-质谱法(GC-MS)检测塑料中对特辛基苯酚残留量的方法。试样经低温冷冻粉碎,丙酮溶解,微波萃取,提取液经浓缩定容进入DB-5MS石英毛细管色谱柱(30 m×0.25 mm,0.25μm)分离,采用GC-MS选择离子检测,外标法定量。结果表明,在(0.1~2.0)mg/L范围内,相关系数r大于0.99,方法检出限为0.221μg/L,定量限为0.737μg/L。当添加对特辛基苯酚含量为0.1、0.2、0.5、1.0、2.0 mg/L时,加标回收率在85.7%~105.0%之间,其RSD数为2.1%~3.3%(n=6)。该方法具有方法科学、准确、实用性强、样品处理简单、分析速度快、选择性和重复性好、便于高通量使用等特点。适用于塑料中对特辛基苯酚残留量的检测,易于推广应用。     

固相萃取-气相色谱-质谱法测定茶叶中蒽醌残留

建立固相萃取-气相色谱-质谱法测定茶叶中蒽醌残留的方法。茶叶经0.1%乙酸乙腈(V/V)提取,盐析后旋转蒸发至近干,正己烷溶解,弗罗里硅土柱净化,丙酮-正己烷(2︰8,V/V)洗脱,丙酮定容,气相色谱-质谱(GC-MS)检测。采用HP-5MS色谱柱(30 m×0.25 mm×0.25μm)结合程序升温对样品进行分离,选择SIM反应监测模式,外标法定量。蒽醌在10.0~1000.0μg/L范围内具有良好的线性关系,相关系数为0.9998。茶叶样品在0.01,0.02和0.10 mg/kg 3个添加水平,回收率范围为90.2%~95.0%,相对标准偏差为3.0%~5.5%,检出限为0.002 mg/kg,定量限为0.008 mg/kg。该方法准确、灵敏、快速,可满足茶叶中蒽醌残留的确证检测。     

The role of diisocyanate structure on microphase separation of solution polymerized polyureas

Three diisocyanates with different symmetry and planarity (2,6-TDI, 2,4-TDI and MDI) were used to synthesize polyureas with the same oligomeric polyetheramine having a molecular weight of ∼1000 g/mol. The influence of diisocyanate symmetry on the phase separated morphology, hydrogen bonding behavior, and molecular dynamics were investigated. Symmetric diisocyanate structures facilitated self-assembly of hard segments into ribbon-like domains, driven by strong bidentate hydrogen bonding. The hard domains for the 2,6-TDI polymer appear to be continuous in AFM images, while the persistence length of the hard domains in the 2,4-TDI and MDI polymers gradually decrease, and fewer hard domains are apparent with decreasing hard segment symmetry. The extent of hard/soft segment demixing, assessed from small-angle X-ray scattering, was very incomplete for all of the polyureas and is significantly influenced by hard segment structure. For the 2,4- and 2,6-TDI polyureas, two segmental relaxations were observed using dielectric relaxation spectroscopy; one arising from relatively unrestricted motion in the soft segment rich phase, and a slower process associated with segments in the soft phase constrained by their attachment to hard domains.     

离子型形状记忆聚氨酯的合成和性能研究

最用2,4-甲苯二异氰酸酯、不同分子量的聚己二酸丁二醇酯、1,4-丁二醇和二羟甲基丙酸为原料,以三乙胺为成盐剂,合成了一系列离子型形状记忆聚氨酯材料·通过DSC分忻、DMA分析、弯曲实验和透湿气实验研究了该材料的性能,并与普通非离子型形状记忆聚氨酯进行了比较,发现前者具有更优越的形状与透湿气性能。     

形状记忆聚氨酯的结构与性能研究

以2，4-甲苯二异氰酸酯、不同相对分子质量的聚己二酸丁二醇酯(PBAG)和1，4-丁二醇为原料合成了一系列聚酯型聚氨酯弹性体。发现由相对分子质量为3000和5000的PBAG所合成的聚氨酯弹性体具有良好的形状记忆功能。通过DSC、弯曲试验和力学性能测试研究了形状记忆聚氨酯的性能，发现软段高度结晶和硬段聚集形成硬段微区是使聚氨酯具有较好形状记忆功能的必要条件。     

星型结构四官能团丙烯酸酯光固化树脂的合成

以2,4-甲苯二异氰酸酯(2,4-TDI)、季戊四醇、丙烯酸羟乙酯(HEA)为原料合成了星型结构的丙烯酸酯,该树脂稳定性好,力学性能优良,原料易得且价格低廉,用途广,利于工业规模生产。文中探讨了反应温度、反应时间和单体投料比对星型结构四官能团丙烯酸酯光固化树脂合成的影响。结果表明,最佳的合成条件为:第一步合成温度控制在45~50℃,反应时间80 min;第二步合成温度控制在65~70℃,反应时间60min;季戊四醇、2,4-甲苯二异氰酸酯和丙烯酸羟乙酯的物质的量比为1∶4∶4.08。实验表明该合成方法简单,反应温和,易控制,生产工艺清洁。     

Low-temperature behavior of polyurethane elastomers

A study of the performance at low temperatures of various polyurethane elastomer systems, prepared from polyether and polyester diols with 2,4-toluene diisocyanate and 4,4′-methylenebis(2-chloroaniline), p,p′-diphenylmethane diisocyanate and 1,4-butanediol, and 4,4′-methylenebis(cyclohexylisocyanate) and methylenedianiline, has shown the polytetramethylene ether diols to impart the best low-temperature behavior to the elastomers. The properties studied were the apparent modulus of rigidity with the Clash and Berg torsional apparatus, the hardness with a Shore D Durometer, and the resiliency with the Bashore Resiliometer.     

主链型液晶聚氨酯的合成及性能研究

以4,4′–二羟基联苯与6–氯–1–己醇为原料,合成一种具有液晶性的中间体4,4′–双(6–羟己氧基)联苯(BHHBP),再分别与1,6–己二异氰酸酯、甲苯–2,4–二异氰酸酯、异氟尔酮二异氰酸酯、4,4′–二苯基甲烷二异氰酸酯、苯二甲基二异氰酸酯反应合成了五种结构不同的主链型液晶聚氨酯(PUR)。用核磁共振波谱仪、傅立叶变换红外光谱仪、热重分析仪、差示扫描量热分析仪、偏光显微镜和X射线衍射仪等表征了中间体BHHBP以及所合成的PUR的结构与性能,并详细探讨了PUR的结构对材料热性能和液晶性能的影响。     

Preparation and properties of UV-curable polydimethylsiloxane urethane acrylate

A new type of a UV-curable polyurethane acrylate resin based on hydroxyterminated polydimethylsiloxane (PDMS) soft segments with molecular weight 1800 and 2,4-toluene diisocyanate (TDI)/2-hydroxyethyl methacrylate (HEMA) hard segments were synthesized. The reactivity of 2,4-TDI with the hydroxy groups of silanol and HEMA was discussed by means of IR measurements. The characteristic absorption peaks of the —NCO groups of 2,4-TDI in the para- and ortho-position should decline with increasing the reaction time. The measurements of fundamental physical properties of this type of UV-curable materials had been widely studied in addition to the effects of using various reactive diluents and some pigments. This kind of resin with good optical, electrical insulating, and adhesive properties on various matrices, could be improved in chemical properties and reduced in viscosity while promoting the coating processability by mixing with various reactive diluents. The excellent adhesive properties on glass plates can be attributed to the similar structure between the PDMS soft segments and glass which makes the application in the coating industry possible.     

2,4-TDI/共沸剂二元体系的汽液平衡数据的测定及共沸组成分析

在脱除游离甲苯二异氰酸酯(F-TDI)的共沸蒸馏研究中,缺少2,4-TDI与共沸剂的二元体系汽液平衡数据及基础热力学参数。采用自制的汽液平衡釜,测定了0.55 kPa压力下,2,4-TDI/苯甲酸乙酯、2,4-TDI/丁二酸二乙酯、2,4-TDI/己二酸二甲酯三组二元体系的汽液平衡数据,所得数据通过了热力学一致性面积检验。借助流程模拟软件Aspen Plus对实验数据进行了回归,得到3组UNIQUAC模型参数及关联偏差,气相摩尔分数平均偏差分别为0.0067、0.0083和0.0179,平衡温度平均绝对偏差分别为0.7 K、1.2 K和0.5 K。进而对共沸体系进行了共沸分析,得到了共沸组成和共沸条件,为F-TDI的共沸分离技术提供了工艺参数。     

15N CP/MAS NMR Study of the Isocyanate/Wood Adhesive Bondline. Effects of Structural Isomerism

Structurally isomeric ¹⁵N-labeled polymeric methylenebis(phenylisocyanate), pMDI, adhesives were synthesized. One resin had a high content of 4,4'-MDI, and another was prepared with a high content of 2,4'-MDI. Both resins were cured with wood (Liriodendron tulipifera) for various times and temperatures and then analyzed using ¹⁵N CP/MAS NMR. It was found that resin polymerization occurs via the reaction of isocyanate with wood moisture to form polyurea. Biuret formation and isocyanate dimerization were detected. Urethane formation probably also occurs; however, signal overlap of urea and urethane signals prevents a definitive conclusion. These findings are similar to previous ones; however, subtle differences are noted. The structurally isomeric resins displayed similar chemistries. Of the two resins, the resin prepared with a high content of 2,4'-MDI cured more slowly, and resulted in a network that was more mobile in the midkilohertz frequency range. This leads to the prediction that resins high in 2,4'-MDI may have a superior performance in impact loading.     

A small-angle X-ray scattering study of microphase separation transition of polyurethanes: Effect of hard segments

Three segmented polyurethane block copolymers PU-M, PU-X and PU-T containing different diisocynates, diphenylmethane-4,4'-diisocyanate (MDI), xylene diisocyanate (XDI) and 2,4-toluene diisocyanate (TDI) respectively with the same chain extender 1,4-butanediol (BD) and soft segment polyester-diol were investigated by small-angle X-ray scattering (SAXS). Microphase separation transition (MST) occurred due to the thermodynamic incompatibility between the soft and hard segments. The long domain spacing, interfacial thickness (or transition layer thickness), core zone, and lamellar thickness were determined for these three different polyurethanes from one dimension correlation function after the Fourier transformation of small-angle X-ray scattered intensity curve based on the Strobl and Schneider model. The structural parameters for these three polyurethanes determined from the scattering measurements indicate that the degrees of microphase separation are in the following sequence: PU-M > PU-X > PU-T.