聚苯醚磺酸锂与酯类增塑剂共混物的导电性

聚苯醚磺酸锂与酯类增塑剂共混物的导电性汪传清，黄玉惠，赵树录，丛广民（中国科学院广州化学研究所广州５１０６５０）关键词　聚苯醚磺酸锂，酯类增塑剂，共混，导电性能高分子固体电解质［１］可作为高能电池、电致变色等材料。聚环氧乙烷／碱金属盐复合物与无机盐构...     

Application of ionic liquids as low-volatility plasticizers for PMMA

Room temperature ionic liquids (ILs) based on imidazolium salts, were found to be excellent plasticizers for poly(methyl methacrylate), with improved thermal stability, and the ability to reduce glass transition temperatures to near 0 °C. Because ILs have environmentally benign properties, they can be used in place of traditional chemicals in numerous products and processes. In this work, PMMA was formulated using dioctyl phthalate, DOP, as a traditional plasticizer, and properties were compared to PMMA plasticized with two ILs: butyl methylimidazolium/hexafluorophosphate, [bmim⁺][PF₆⁻], and hexyl methylimidazolium/hexafluorophosphate, [hmim⁺][PF₆⁻]. Formulations incorporated up to 30 vol.% DOP and 50 vol.% ILs. Bulk and plasticized polymers were characterized for glass transition temperature, elastic modulus, and the thermal stability of the plasticizers.     

Effect of benzenesulfonamide plasticizers on the glass‐transition temperature of semicrystalline polydodecamide

The effect of various benzenesulfonamide (BSA) plasticizers on the amorphous phase of semicrystalline polydodecamide (PA‐12) has been investigated. MonoBSAs appear as efficient glass‐transition temperature (T_g) depressors because of their miscibility with the host polyamide (PA), low glass transition, and small molecule size. PA‐12's T_g shifts from 50 to about 0 °C at 20 mol % of the most efficient molecules. Comparatively, the more bulky bisBSAs appear to induce less important absolute T_g decreases (30 K at 20 mol %), although these appear as more important when considering the polymer T_g to plasticizer T_g difference. This unexpected observation could be ascribed to both the amide‐sulfonamide interactions and the sterically generated disorder within the polyamide because of the plasticizer molecule's size. Phase‐separation behavior of BSA plasticizers within the host PA has also been investigated. Crystalline phenyl‐SO₂NH₂, for instance, dephased beyond 20 mol % in PA‐12, forming distinct 1–2 micrometer wide crystalline domains as a result of its high propensity to crystallize upon cooling from the melt. By contrast, slow crystallizing N,N‐dimethylBSA, which lacks any specific interaction for PA‐12, remained nevertheless dispersed at a molecular level (metastable state, no phase separation) when vitrification of the host PA‐12 amorphous phase occurred on cooling. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2208–2218, 2002     

Effect of Dodecyl Alcohol on the Potentiometric Response of an Isopropyl Xanthate Ion-Selective Electrode

An isopropyl xanthate ion-selective electrode was constructed using as a carrier the complex trioctylmethylammonium-isopropyl xanthate. Two kinds of plastic membranes were built, with dioctyl phthalate (DOA) and dioctyl adipate as plasticizers. In both cases, the electrical responses were linear in a wide range of xanthate concentrations, with the limit of detection between 10(-4) and 10(-5) M. The electrical response was improved by adding only 3 &mgr;mol of dodecyl alcohol per membrane. This fact seems to indicate not only that the fluidity is relevant but also that the surface polarity of the plastic membrane plays an important role. The analysis of some added salts shows that isobutyl xanthate is a strong interfering agent for the DOA electrode. Nitrate interferes weakly, whereas chloride, acetate, and carbonate do not affect the electrical response of both kinds of electrodes. Copyright 2001 Academic Press.     

HTPB固体推进剂增塑剂选取分子模拟研究

固体推进剂中增塑剂要求同粘合剂体系相容性良好,并提高体系的低温性能.本文采用分子动力学(MD)方法,首先计算了端羟基聚丁二烯(HTPB)粘合剂及增塑剂癸二酸二辛酯(DOS)、己二酸二辛酯(DOA)、壬酸异癸酯(TOA)、邻苯二甲酸二丁酯(DBP)和邻苯二甲酸二辛酯(DOP)的溶度参数,以此从相容性角度选取推进剂增塑剂;计算数值基本吻合实验值,表明常用的增塑剂从相容性都能满足要求.其次模拟获取了HTPB及HTPB/增塑剂混合体系的比体积-温度关系得到了体系的玻璃化转变温度(Tg),揭示增塑剂对HTPB体系低温性能的影响.结果显示:(1)HTPB的Tg模拟值为202K,基本吻合实验值196K.(2)HTPB/DOS混合体系中,当增塑剂DOS的质量含量从12%、22%、29%到36%(摩尔含量分别为50%、66%、75%和90%)增加时,体系的Tg线性降低;TOA和DOP增塑的粘合剂体系(摩尔含量为75%)Tg也降低,而增塑剂DOA和DBP对体系的Tg影响不大.因此,基于相容性及提高粘合剂低温性能考虑,DOS、DOA和DOP作为HTPB的增塑剂优于TOA和DBP.     

Preparation of flame retardant polyamide 6 composite with melamine cyanurate nanoparticles in situ formed in extrusion process

This paper is focused on in situ preparation of melamine cyanurate (MCA) nanoparticles from reaction of melamine (MEL) and cyanuric acid (CA) and their flame retardant polyamide 6 (PA6) composite in the extrusion process through a novel reactive processing method. Fourier transform infrared (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were utilized to characterize the in situ formed MCA nanoparticles and their blends with PA6. Introduction of pentaerythritol (LTP) and water-bound plasticizer dioctyl phthalate (DPT) into the extrusion reaction system greatly inhibits the evaporation of water required for melamine and cyanuric acid reaction at high temperature (higher than 180 °C), laying a foundation for successful in situ preparation of MCA through reactive processing. XRD and FT-IR measurements indicate that under the effect of pentaerythritol, dioctyl phthalate and water, melamine really reacts with cyanuric acid to in situ form MCA in extrusion process. The reaction degree is close to 100%. A very important finding through SEM is that the in situ formed MCA particles, which were found to have aspect ratio of about 7.5, radial size in the range of 70-300 nm (mostly 70-90 nm) and crystallite size of less than 22 nm, are uniformly dispersed in the matrix PA6 at nanoscale. The in situ formed MCA nanoparticles greatly improve the flame retardancy and the mechanical properties of flame-retarded PA6 materials, and the introduced plasticizer dioctyl phthalate also ameliorates the related impact property. The obtained flame-retarded PA6 materials have good comprehensive performance with flame retardancy UL-94 V-0 rating at 1.6 and 3.2 mm thickness, tensile strength 48.0 MPa, elongation at break 106.3% and Izod notched impact strength 8.92 kJ/m². Compared with flame-retarded PA6 material with in situ formed MCA, the one prepared through conventional blending of PA6 with commercial MCA product has improved tensile strength but deteriorated impact strength and flame retardancy.     

Branched plasticizers derived from eugenol via green polymerization for low/non-migration and externally/internally plasticized polyvinyl chloride materials

The synthesis of nontoxic plasticizers derived from the waste residues of the rosin-processing industry can reduce pollution and promote the high-value utilization of the waste residues of rosin. In this study, four kinds of sustainable branched plasticizers derived from a biomass resource, eugenol (derived from the waste residues of the rosin processing industry), were synthesized via one-pot solvent free polymerization and used to plasticize polyvinyl chloride (PVC). Internally plasticized PVC was fabricated using thiolated DPE (branched plasticizers based on eugenol). The thermal stability, tensile properties, microstructure, volatility behavior, and solvent extraction resistance of plasticized PVC were investigated. Compared with the behavior of the commercial plasticizer dioctyl phthalate, the thermal stability, plasticizing efficiency, and migration resistance of the branched plasticizers are superior. The acute oral toxicity dose of each branched plasticizer was extremely high at 5000 mg/kg of body weight, with no deaths among test animals. Compared with externally plasticized PVC, the internally plasticized PVC showed zero weight loss in volatility and leaching tests despite its less effective plasticization. All the branched plasticizers have potential application in plastic products.     

SBS/Pani · DBSA mixture plasticized with DOP and NCLS - Effect of the plasticizers on the probability density of volume resistivity measurements

Plasticized mixtures of styrene-butadiene-styrene block copolymer (SBS) and Polyaniline (Pani) were prepared in a Haake internal mixer. Two different plasticizers were used: dioctyl phthalate (DOP) and cashew nut shell liquid (CNSL). Pani and plasticizers were characterized by FTIR and the resistive behavior of plasticized mixtures was investigated along the electrification time. It is shown that obtained experimental data are subject to deterministic dynamic fluctuations that cannot be described by single normal probability distribution functions (PDF) along the time. The PDF analysis shows that obtained PDFs must be described as sums of at least three distinct Gaussian distributions with different areas. It is also shown that the Gaussian component with larger area may provide better representation of the measured volume resistivity values.     

Analysis of poly(vinyl chloride) additives by supercritical fluid extraction and gas chromatography

The use of supercritical fluid extraction (SFE) is growing, with an expanding range of applications in many different fields as a consequence of its advantages compared with traditional extraction methods. In order to develop an analytical method to determine dibutyl phthalate (DBP) and dioctyl phthalate (DOP) traces (<20 ppm) in flexible poly(vinyl chloride) (PVC) formulations, a maximum efficiency in the extractive process and an adequate separative system are needed to avoid interferences between these two plasticizers and other additives that could be present at high concentrations in flexible PVC formulations. In order to determine the optimum SFE conditions, the extraction time, temperature and pressure were controlled. The separation and quantitation of individual components in the PVC extracts were carried out off-line by using a semicapillary column in gas chromatography (GC). Samples with different DOP content (41.18%, 33.33% and 23.08%) and DBP content (41.18%), as well as samples with both plasticizers (20.59% DOP and 20.59% DBP) were prepared. Some other samples were also prepared to study detection limits for these two PVC additives. Recoveries and reproducibilities were studied in every sample. Finally, this method was compared with Soxhlet liquid extraction. Determination by gravimetric analysis of the total extracted material was found to be particularly suitable for PVC. This study demonstrates the potential of SFE to shorten extraction times with similar or even better extraction efficiencies compared with traditional liquid methods.     

Influence of Reactive Compatibilization on the Melt Flow Properties and Morphology of Polyamide 6/Styrene-Acrylonitrile Blends

Summary: In this study, we investigate the influence of reactive compatibilization on the rheological properties of polyamide 6/styrene-acrylonitrile (PA 6/SAN) blends in the melt. Linear viscoelastic shear oscillations, simple elongation to a large stretch ratio and subsequent recovery experiments were performed. The morphology of the blends was examined by atomic force microscopy. We prepared three PA 6/SAN blends with different composition ratios of PA 6 and SAN (70/30, 50/50, 30/70) and a constant concentration of the reactive agent. Our experiments revealed that reactive compatibilization significantly increases the complex modulus of PA 6/SAN blends at low frequencies. In particular, the data of the PA 6/SAN 50/50 blend and the PA 6/SAN 30/70 blend indicated that an elastic network between neighbouring PA 6 domains was formed. In simple elongation, the transient elongational viscosity of the blends exceeded the values of the single components. In recovery, the recovered stretch of all blends was larger than the recovered stretch of the pure components. The differences of the blend morphology and of the linear viscoelastic behaviour were qualitatively explained by the asymmetric properties of the reactively compatibilized interface.     

Ester plasticizers for polyvinyl chloride

The review covers information from patents and papers that have been published in the past 5 years and deal with the synthesis of ester plasticizers for polyvinyl chloride. The main trends in the progress of this field are analyzed. Data on new esterification catalysts are presented. Particular attention is paid to plasticizers derived from terephthalic acid, which show promise for replacing toxic dioctyl phthalate. The results of studies on synthesis and properties of nonphthalate plasticizers based on benzene, toluene, naphthalene, cyclohexane, and norbornene are considered. Synthesis methods and prospects for using plasticizers derived from renewable vegetable raw materials, namely, citrates, succinates, triglycerides, fatty acid esters, and sugar derivatives, are discussed.     

Preparation and characterization novel dioctyl terephthalate blended polyvinyl alcohol-composite films incorporated with the graphene oxide and silver nanoparticles

Dioctyl terephthalate is of great interest as a replacement for the phthalate plasticizers such as dioctyl phthalate and diisononyl phthalate due to its orthophthalate-free and non-carcinogenic properties. This study focused on the production, characterization and optimization of the quality characteristics of its film properties, such as the mechanical, hydrophilic and thermal properties of dioctyl terephthalate-blended polyvinyl alcohol composites modified with graphene oxide and silver nanoparticles using TOPSIS (Technique for Order Preference by Similarity to an Ideal Solution) based Taguchi Method. Dioctyl terephthalate has brought remarkable features, such as high elastic modulus, and hydrophilic and thermal stability to the polyvinyl alcohol matrix. The optimum Dioctyl terephthalate -blended polyvinyl alcohol films have a 2.26 times lower contact angle and a 13.41 times higher elastic modulus than the reference polyvinyl alcohol film. Dioctyl terephthalate should be preferentially used to manufacture more durable and hydrophilic composite films such as fibers, disposable underpad or industrial swab, instead of toxic phthalate plasticizers.     

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     

Ecotoxicity of the Adipate Plasticizers: Influence of the Structure of the Alcohol Substituent

A significant increase in the production of plastic materials and the expansion of their areas of application contributed to the accumulation of a large amount of waste of polymeric materials. Most of the polymer composition is made up of plasticizers. Phthalate plasticizers have been recognized as potentially hazardous to humans and the environment due to the long period of their biodegradation and the formation of persistent toxic metabolites. It is known that the industrial plasticizer dioctyl adipate is characterized by reduced toxicity and a short biodegradation period. The paper describes the synthesis of a number of new asymmetric esters based on adipic acid and ethoxylated butanol by azeotropic esterification. The receipt of the products was confirmed by IR spectra. The physicochemical properties of the synthesized compounds were investigated. The glass transition temperatures of PVC composites plasticized with alkyl butoxyethyl adipates were determined using DSC analysis. The ecological safety of esters was assessed by the phytotesting method. Samples of adipates were tested for fungal resistance, and the process of their biodegradation in soil was also studied. It is shown that the synthesized esters have good plasticizing properties and are environmentally safe. When utilized under natural conditions, they can serve as a potential source of carbon for soil microorganisms and do not form stable toxic metabolites; therefore, they are not able to accumulate in nature; when the plasticizers under study are disposed of in the soil, toxic substances do not enter.     

Preparation and properties of novel plastisols based on acrylic core-shell lattices

A series of core-shell lattices comprising a core portion of rubbery acrylic homo- or copolymers and a surrounding shell portion of glassy methyl methacrylate (MMA) homo- or copolymers were designed as plastisols for automotive underbody coatings. The lattices were synthesized by a semi-continuous seeded emulsion polymerization and characterized by using differential scanning calorimetry (DSC) and scanning electronic microscopy (SEM). DSC investigations demonstrated that the incorporation of a hard segment of MMA into the core portion and strongly polar monomer methyl acrylic acid (MAA) or cross-linker allyl methacrylate (ALMA) into the shell portion resulted in an improvement of the glass transition temperatures. SEM micrographs verified that the latex particles were always spherical with regular structure throughout the polymerization stage. Novel plastisols were developed based on the abovementioned core-shell polymers with dioctyl phthalate (DOP) or tricresyl phosphate (TCP) plasticizers, whose core portions were compatible with the employed plasticizer and whose shell portions were incompatible with the plasticizer. Evaluation of the viscosity as a function of the storage time revealed that the storage stability of the plastisols could be obtained through incorporation of the strongly polar monomer MAA or the cross-linker ALMA into the shell portions. The mechanical properties of the plastigels were improved by incorporating MMA into the core portion or by incorporating MAA or ALMA into the shell portion of the lattices. A balance between the mechanical properties of plastigels and the storage stability of plastisols should be considered during selection of the monomers both for the core and shell.     

Properties of irradiated PVC plasticized with non-endocrine disruptor

Polyvinylchloride (PVC) is under heavy attack from environmentalist groups due to the use of plasticizers and its recycling difficulties. Chloro-organics and phtalates are considered now as ubiquitous global contaminants due to their potential as weak endocrine disruptor and huge consumption. In order to make PVC acceptable for the irradiation processing industry in the long term, non-toxic plasticizers should be used. PVC was added with dioctyl phtalate (DOP) and epoxy soybean oil (ESO) and irradiated up to 50 kGy. Mechanical properties, optical properties and viscosity were measured and compared. The elongation and mechanical strength were under the usual range and they didn’t show any significant change in the studied range of irradiation dose. All the samples showed a weak yellowing effect after irradiation and the molecular weight measured by viscosimetry showed only negligible changes. In conclusion, DOP and ESO were shown to be effective in stabilizing the radiolytic abstraction of HCl from PVC. Both plasticizers imparted good color stability and overall properties to the products.     

Novel bilirubin-based PVC calcium sensors.

Poly(vinyl chloride) membrane sensors for Ca(II) ions were constructed based on bilirubin (1,3,6,7-tetramethyl-4,5-dicarboxyethy-2,8-divinyl-[b-13]-dihydrobilenone) as a neutral carrier in the presence of various plasticizers (o-nitrophenyloctyl ether, dioctyl phethalate and dibutyl sebacate), which were used as solvent mediators to incorporate the carrier into the membranes. The role of plasticizers as a medium of complexation was demonstrated. The influences of an anionic excluder, the pH and foreign ions were investigated. The selectivity coefficients were measured by a separate solution method. Among the plasticizers used, o-nitrophenyloctyl ether gave the best selectivity in the presence of large concentrations of alkali and alkaline earth's metal ions. Using sensor number I, a linear calibration graph with a good Nernstian slope of 29.5 +/- 0.8 mV was obtained for Ca(II) concentrations of 5 x 10(-7)-10(-2) mol l(-1) with a detection limit of 3 x 10(-7) mol l(-1) (12 ppb). The sensor can be used for more than 3 months with good reproducibility and a fast response time of 10 s. The developed sensor has been successfully applied to the analysis of some pharmaceutical formulations, baby-food products and human plasma. Moreover, it can be used as an indicator sensor in the potentiometric titration of Ca(II) with EDTA.     

Study of the influence of triacylglycerol composition on DSC cooling curves of extra virgin olive oil by chemometric data processing

In this work, a coupled high-pressure liquid chromatography-differential scanning calorimetry-partial least square (HPLC–DSC–PLS) procedure was applied to clarify the influence of triacylglycerol composition on the shape of cooling curves for extra virgin olive oil (EVOo), as chemometric processing of digitized DSC curves was previously reported to be an attractive alternative to the application of the common procedure of parameter extrapolation for the analysis of thermal transition. 69 samples of EVOo were analysed to obtain triacylglycerol (TAG) composition by means of HPLC and DSC cooling profiles. Results obtained by the application of PLS algorithm on TAG concentration (%) and digitized DSC curves showed that cooling transitions were markedly influenced by OOO, OLO and OOP + SLO that are the most representative TAG for EVOo. Other TAG as LLP + OLnO, LLL + LLPo and POPo developed good PLS models, appearing to influence EVOo cooling curve, although less markedly than the further. Otherwise, the other identified TAG did not render appropriate models. Finally, grouping TAG according to different unsaturation degree, high correlation coefficients (>0.80) and low relative standard deviations (<11 %) were found for sum of tri-unsaturated triacylglycerols in both calibration and validation sets. Starting from these encouraging results, this new and fast coupled approach may be applied to a wider set of EVOo samples to tentatively discriminate among oils according to different geographical and/or botanical origins taking into account relation established among TAG and cooling curves.     

Mechanical properties of polyamide-12 layered silicate nanocomposites and their relations with structure

The mechanical properties of polyamide-12/Cloisite 30B (PA12/C30B) nanocomposites prepared by melt compounding were studied as a function of clay volume fraction φ under various processing conditions. All measured mechanical characteristics, Young's modulus, yield stress, strain at break and stress at break, exhibit a transition at φ_p1%, identified with a percolation threshold. Also, the linear and non-linear mechanical properties appeared to depend on the degree of exfoliation of the structure, which can be tuned by the processing conditions. The three-phase Ji's theoretical model was used to predict Young's modulus as a function of clay concentration, focusing on the influence of the degree of exfoliation. Experimental yield stress data were fitted to Pukanszky's model and discussed in terms of PA12/C30B interfacial adhesion.     

Delamination of sodium montmorillonite in PA6 in the presence of melamine polyphosphate

This study describes the influence of melamine polyphosphate (MPP) flame retardant addition on layered structure of virgin sodium montmorillonite (MMT) in PA6/MMT system obtained in extrusion process. It was found that the extrusion of the PA6/MMT binary system in co‐rotating twin screw extruder gives intercalated clay nanocomposites, while during extrusion of ternary PA6/MMT/MPP composite, full exfoliation of clay was obtained in the system. Structure of the composites was proved utilizing wide angle X‐ray scattering and transmission electron microscopy techniques. Exfoliation of MMT in ternary PA6/MMT/MPP system was also confirmed by rheological studies (viscosity and creep measurements) which were carried out using rotational rheometer. Young's modulus of PA6/MMT/MPP was found to be ~25% greater comparing to PA6/MPP of the same filling level. Cone calorimetry experiments proved decrease of heat release rate peak of PA6/MMT/MPP by ~55% comparing to PA6/MPP with the same total filling level. Copyright © 2017 John Wiley & Sons, Ltd.