常见食品中邻苯二甲酸酯类增塑剂含量及食品包装材料中邻苯二甲酸酯类增塑剂迁移量的测定

采用气相色谱-质谱联用(GC-MS)方法并结合液液萃取及基质分散固相萃取的样品处理方式,建立了测定饮料、牛奶、白酒3类食品中16种邻苯二甲酸酯类增塑剂的分析方法。研究结果表明16种邻苯二甲酸酯类增塑剂的检出限(LOD, S/N=3)范围为0.005~0.025 mg/L;峰面积的相对标准偏差(RSD)均小于2%。饮料、牛奶、白酒3种样品的加标回收率范围普遍在60%~110%。所建方法简便、灵敏、准确,可满足饮料、牛奶和白酒中痕量邻苯二甲酸酯类增塑剂的测定需要。此外,将该方法应用于食品包装材料中邻苯二甲酸酯类增塑剂的迁移研究,以异辛烷为油脂食品模拟物,测定了保鲜膜与保鲜袋中16种邻苯二甲酸酯类增塑剂的迁移量。结果显示保鲜膜存在显著的邻苯二甲酸酯类增塑剂迁移现象。     

Syneresis and crystallinity in plasticized rubbery networks and composites

We prepared polycaprolactone networks plasticized (60 wt%) with triacetin, with and without filler particles to model high-energy solid rocket propellants. Under strain and at lower temperatures these materials partially crystallize but also undesirably exude plasticizer (syneresis). We measured both properties isothermally (30°C) on the basis of molecular mobility: crystallinity with rapid-passage cw proton nuclear magnetic resonance (NMR), and syneresis with pulsed-gradient spin-echo NMR diffusion techniques, as a function of strain and time. In the gumstocks crystallinity and syneresis increase monotonically with strain and asymptotically with time. In a given specimen syneresis lags behind crystallinity but they approach the same value, suggesting that syneresis originates in expulsion of plasticizer from crystallizing regions. In the composites, crystallinity results resemble those in gum, but our diffusion data suggest that most syneresis is internal, with plasticizer accumulating in strain-debonded void regions near filler particles. © 1994 John Wiley & Sons, Inc.     

Synthesis of 1,4‐Cyclohexanedimethanol, 1,4‐Cyclohexanedicarboxylic Acid and 1,2‐Cyclohexanedicarboxylates from Formaldehyde,Crotonaldehyde and Acrylate/Fumarate

Valuable polyester monomers and plasticizers—1,4‐cyclohexanedimethanol (CHDM), 1,4‐cyclohexanedicarboxylic acid (CHDA), and 1,2‐cyclohexanedicarboxylates—have been prepared by a new strategy. The synthetic processes involve a proline‐catalyzed formal [3+1+2] cycloaddition of formaldehyde, crotonaldehyde, and acrylate (or fumarate). CHDM is produced after a subsequent hydrogenation step over a commercially available Cu/Zn/Al catalyst and a one‐pot hydrogenation/oxidation/hydrolysis process yields CHDA, whereas 1,2‐cyclohexanedicarboxylate is obtained by a Pd/C‐catalyzed tandem decarbonylation/hydrogenation step.     

Melt properties and crystal morphology of polydodecamide plasticized by benzenesulfonamides

The melt of polydodecamide (PA‐12) shows a significant viscosity decrease upon incorporation of benzenesulfonamide plasticizers (BSAs), this effect being maximum for a monofunctional BSA with a 12‐carbon‐atom‐long alkyl chain. Nonexhaustive X‐ray diffraction analysis developed on isothermally crystallized samples validated a two‐phase model for describing PA‐12 plasticized by N‐(n‐butyl)benzenesulfonamide (BBSA). The massive presence of BBSA between the lamellar crystals was established, and lamellar fragmentation was also observed. Further, a steady increase in PA‐12 crystallinity with an increasing BBSA content was evident (and confirmed by DSC) and is consistent with the plasticizer easing the mobility of polymer chains during crystallization. Large melting point depressions resulting from both polymer–plasticizer miscibility and lamellar fragmentation were observed with several mono‐ and bifunctional BSA plasticizers. Phase separation in PA‐12 solid state was only observed at 20 mol % of ?SO₂NH₂, alhough miscibility occurred in the melt. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2022–2034, 2001     

气相色谱―质谱法测定仿真饰品中磷酸酯类增塑剂含量

建立了仿真饰品中6种磷酸酯类增塑剂含量的气相色谱―质谱测定法。对提取方法、色谱条件及质谱参数进行了研究。结果表明,采用正己烷/丙酮(体积比1∶1)微波萃取样品35 min可获得良好的提取效果。所建立的微波萃取―气相色谱―质谱法的定量限为1～2.5 mg/kg,在1～2个数量级浓度范围内,线性相关系数R2在0.999以上,在三个添加水平下回收率在86.63%～98.13%之间。对市售9种塑料仿真饰品的测定结果表明磷酸酯的存在风险极低。     

固相萃取-气相色谱-串联质谱法测定大葱等蔬菜中23种邻苯二甲酸酯类化合物残留

建立了气相色谱-串联质谱联用(GC-MS/MS)同时测定蔬菜中23种邻苯二甲酸酯类化合物(塑化剂)的方法。蔬菜经乙腈提取,玻璃Florisil固相萃取柱净化,正己烷定容,Agilent DB-5MS UI超高惰性毛细管柱(30 m×0.25 mm×0.25 μm)程序升温分离,MS/MS(选择反应监测模式)分析,外标法定量。考察了大葱等复杂基质蔬菜中邻苯二甲酸酯类化合物的提取和净化方法,并对色谱和质谱条件进行了优化,提出了扣除本底的办法;通过基质加标校准曲线补偿对邻苯二甲酸酯检测的基质效应。23种邻苯二甲酸酯的线性范围除邻苯二甲酸二异壬酯(DINP)、邻苯二甲酸二异癸酯(DIDP)为0.1~5 mg/L外,其余均为0.02~1 mg/L,相关系数(r)除邻苯二甲酸二(2-甲氧基乙基)酯(DMEP)外均大于0.99。方法的检出限(S/N=3)为0.01~0.05 mg/kg,定量限(S/N=10)为0.02~0.1 mg/kg。3个加标水平下目标物的平均回收率为81.3%~104.2%,相对标准偏差(n=6)为3.2%~11.2%。该方法稳定可靠,应用串联质谱很好地消除了基质效应的干扰,灵敏度高,定性定量更为准确,适用于蔬菜中邻苯二甲酸酯类化合物的检测和确证。     

Poly(propylene imine) dendrimers as plasticizers for polyvinyl chloride

Fourth and fifth generation poly(propylene imine) dendrimers and methyl and benzyl functionalized copolymers of these dendrimers are solution blended with poly(vinyl chloride) (PVC). The methyl‐derivative copolymer is observed to be dispersed in PVC as judged by optical and dynamic scanning calorimetry measurements. This dispersion leads to a substantial reduction in the glass transition temperature and a commensurate plasticization effect, demonstrating that functionalized dendrimer copolymers can successfully plasticize semicrystalline polymers. This plasticization is thought to occur as a result of additional free volume from the highly branched structure of the dendrimer. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1970–1975, 2007     

Effect of Solvent (Plasticizers) on PVC Degradation

Both plasticized (semi-rigid and flexible) PVC materials as well as PVC in solutions, the rate of their thermal degradation and effective stabilization are caused by essentially different fundamental phenomena in comparison to aging of PVC in absence of the solvent. Both structure and macromolecular dynamics render the significant influence on its stability, i.e. chemical nature of the solvent (plasticizer), its basicity, specific and non-specific solvation, degree of PVC in a solution (solubility), segmental mobility of macromolecules, thermodynamic properties of the solvent (plasticizer), formation of associates, aggregates, etc. The chemical stabilization of PVC plays a less significant role. The effect of above factors on stability (behavior) of semi-rigid and flexible PVC will be done on quantitative level. It will be described effect of “echo”-type of stabilization on the stability of PVC in the presence of plasticizers. If we would like to have stable material from PVC we should make stabilization of plasticizers as more reactive chemical compounds.     

PVC formulation study for the manufacturing of a skin smart structure based in optical fiber elements

The development of smart solutions based on optical fiber technology for any kind of structure such as buildings, aircrafts, or even for human body kinematics, is becoming more and more common. The ability to provide coverings for different structures that can enable monitoring functions beside the esthetic purpose of the covering is an important add‐value characteristic. Nevertheless, an open issue is to find an effective solution for the fabrication and application procedure, preferably that scales at a production level. This article explores the insertion of optical fibers into polymeric PVC foils based on the spread‐coating fabrication process. The success of this integration approach allows the use of photonic technology in different fields with minor application issues. The material choice for the substrate is a crucial step when choosing integrated solution. Three PVC paste formulations were explored in order to guarantee the optimal integration of optical fiber. A high‐viscosity and not monolithic paste formulation emerged as the best choice. This formulation provided the best adhesion, reducing in great scale the surface undulation and paste displacement that the optical fiber tends to do and, its 362% stretch capability is sufficient for special applications, as strain sensitive one. Copyright © 2010 John Wiley & Sons, Ltd.     

Nitroxy/Azido‐Functionalized Triazoles as Potential Energetic Plasticizers

The synthesis of a series of nitroxy‐ and azido‐functionalized compounds, based on 4‐amino‐3,5‐di(hydroxymethyl)‐1,2,4‐triazole, for possible use as an energetic plasticizers is described. All compounds were fully characterized. Two of them were further confirmed by X‐ray single crystal diffraction. Energetic performance was calculated by using EXPLO5 v6.01 based on calculated heats of formation (Gaussian 03) and experimentally determined densities at 25 °C. The results show that the nitration product 1‐nitro‐3,5‐di(nitroxymethyl)‐1,2,4‐triazole, containing a nitro group and two nitroxy groups, exhibits good detonation properties (D=8574 m s^?1, P=32.7 GPa). In addition, its low melting point makes it very attractive as an energetic plasticizer in solid propellants.