PP-g-(GMA-co-St)对PA6/PC共混物的反应增容作用

用红外、扫描电镜、熔体流动速率和力学性能等测试方法,研究了甲基丙烯酸缩水甘油酯(GMA)和苯乙烯(St)多单体熔融接枝聚丙烯[PP-g-(GMA-co-St)]对PA6/PC共混物的反应增容作用.研究结果表明,在熔融共混过程中,PP-g-(GMA-co-St)中的环氧基与PA6的端氨基及PC的端羟基原位生成的接枝共聚物有效地降低了共混物相间的界面张力,明显提高了共混物相界面的粘着力.少量的PP-g-(GMA-co-St)就能使PA6和PC的相容性得到显著改善.当PP-g-(GMA-co-St)的质量分数为10%时,共混物分散相的相区尺寸细化到0.2μm,其力学性能也有较大提高.PA6/PC/PP-g-(GMA-co-St)共混物的力学性能均衡,达到了弹性体增韧体系难以达到的效果.即使PP-g-(GMA-co-St)组分含量为20%时,共混物仍能保持较好的力学性能,特别是在共混物的韧性得以提高的同时,其强度和伸长率也提高.     

PA6/HIPS/PP-g-(GMA-co-St)反应共混体系的研究

通过扫描电镜、热分析、熔体流动速率、熔融扭矩和力学性能等测试方法研究了甲基丙烯酸缩水甘油酯(GMA)和苯乙烯(St)多单体熔融接枝聚丙烯[PP-g-(GMA-co-St)]对PA6/HIPS共混物的熔融流变性能、结晶行为、相形态和力学性能的影响.结果表明,在熔融共混过程中,PP-g-(GMA-co-St)中的环氧基与PA6的端氨基原位生成的接枝共聚物有效地降低了共混物的界面张力,提高了共混物的界面粘着力,使共聚物的流动速率降低,熔融扭矩提高;PA6分子链的规整性降低,结晶完善性变差.在PP-g-(GMA-co-St)的质量分数为10%时,共混物分散相的尺寸明显减少,力学性能得到较大提高;其中冲击强度超过纯PA6,达到HIPS水平.通过反应共混,制备了力学性能均衡的PA6/HIPS/PP-g-(GMA-co-St)共混物合金.     

POE-g-PMAH反应性增容PA1010/PP共混物的性能研究

乙烯-辛烯共聚物-g-聚马来酸酐(POE-g-PMAH)作为反应性增容剂,采用熔体共混的方法制备了PA1010/PP共混物,通过扫描电镜(SEM)、力学性能、傅立叶变换红外光谱(FTIR)和示差扫描量热(DSC)测试,研究了POE-g-PMAH对PA1010/PP共混物的增容作用.结果表明,POE-g-PMAH的加入可以减小共混物的相区尺寸,当PA1010/PP/POE-g-PMAH=70/30/15时,分散相尺寸小而均匀;FTIR结果表明接枝在POE上的马来酸酐基团和PA1010在熔融共混期间发生了化学反应;DSC研究结果表明共混体系中PA1010和PP的结晶温度和结晶度随POE-g-PMAH的加入而降低,表明POE-g-PMAH的增容作用对PA1010和PP的结晶有抑制作用.力学性能测试结果表明随着POE-g-PMAH的增加,共混物的冲击强度逐渐增加,当POE-g-PMAH含量增加到15%时,干态冲击强度达到21.13 kJ/m2,是不加增容剂的3.1倍,而拉伸和弯曲强度可以保持较高水平.POE-g-PMAH的增容机理在于其支链中的马来酸酐能与PA1010中的胺基(NH2—)发生化学反应,而主链POE与PP有较好的亲和性,从而降低界面张力,减少相区尺寸,大幅度提高力学性能.     

双路易斯酸催化原位增容乙烯辛烯共聚物/苯乙烯共混物的研究

采用新型双路易斯酸, 三甲基氯硅烷和三氯化铟,为催化剂引发傅氏烷基化反应,实现了乙烯辛烯共聚物（POE）和聚苯乙烯（PS）共混物的原位增容。红外光谱验证了接枝物的存在。用扫描电镜观察了反应共混体系和简单物理共混物的形态, 前者分散相的尺寸小于1 μm, 后者分散相的尺寸则较大, 一般为3～4 μm。原位生成的接枝物起到相容剂的作用,增容后的样品的力学性能得到较明显的提升。如：当POE /PS 为40/60 (wt%) 时, 与相同组成的物理共混的POE/PS 相比, 其悬臂梁冲击强度由1.9 kJ/m2 增加到9.7 kJ/m2, 断裂伸长率由3.4%提高到46.3%。增容后共混物的流变性能与物理共混物相比也发生了显著的变化。     

PP—g—（GMA—co—St）对PA6—PC共混合的反应增容作用

用红外、扫描电镜、熔体流动速率和力学性能等测试方法,研究了甲基丙烯酸缩水甘油酯（GMA）和苯乙烯（St）多单体熔融接枝聚丙烯PP－g-(GMA-co-St)对PA6－PC共混合的反应增容作用。研究结果表明,在熔融共混过程中,PP－g-(GMA-co-St)中的环氧基与PA6的端氨基及PC的端羟基原位生成的接枝共聚物就有效地降低了共混物相间的界面张力,明显提高了共混物相界面的粘着力。少量的PP－g-(GMA-co-St)就能使PA6和PC的相容性得到显著改善。当PP－g-(GMA-co-St)的质量分数为10％时,共混物分散相的相区尺寸细化到0．2μm,其力学性能也有较大提高。PA6／PC／PP－g-(GMA-co-St)共混物的力学性能均衡,达到了弹性体增韧体系难以达到的效果。即使PP－g-(GMA-co-St)组分含量为20％时,共混物仍能保持较好的力学性能,特别是在共混物地韧性得以提高的同时,其强度和伸长率也提高。     

PBT/POE-g-MAH/PP共混体系的相态结构与性能

采用马来酸酐接枝乙烯-辛烯共聚物弹性体(POE-g-MAH)与聚丙烯(PP)在双螺杆挤出机上进行熔融共混,制备了3种新型增韧改性剂.研究了增韧改性剂的种类及其用量对共混物的力学性能、相形态结构、熔融与结晶行为的影响.力学性能测试表明,POE-g-MAH与适量PP并用具有显著的协同增韧作用,当POE-g-MAH与PP的配比为70/30时,所得增韧改性剂(POEg2)具有最佳的增韧效果.当POEg2含量达到15%时,共混物的缺口冲击强度(Is)从纯PBT的7.5 kJ/m2提高到51.2 kJ/m2,与15%的纯POE-g-MAH弹性体增韧PBT具有相近的缺口冲击强度值.同时,共混物的拉伸强度(σb)损失最小.采用AFM和SEM观察发现,新型增韧改性剂作为分散相具有软壳-硬核结构.DSC测试表明,随增韧改性剂中PP含量增加到一定值时,壳-核结构中软壳层出现不完整现象,导致界面作用力减小,共混物的Is和σb都出现明显下降.     

ABS的MAH/St多单体熔融接枝及其对PA6/ABS共混体系相形态和力学性能的影响

通过多单体熔融接枝的方法制备出了具有较高接枝率的ABS接枝物 (ABS g (MAH co St) ) ,并对其接枝机理进行了初步探讨 .研究表明 ,MAH、St接枝ABS时 ,反应主要发生在ABS中聚丁二烯的双键部位 .同时 ,当MAH与St的用量比约为 1:1时接枝率达到最高 .ABS g (MAH co St)作为尼龙 6 (PA6 ) ABS共混体系相容剂起到了良好的增容效果 .实验证明 ,相容剂使用前后 ,共混物的相区尺寸由几十 μm减小到 1μm以下 ,且分布更加均匀 ;共混物的拉伸强度和冲击强度等力学性能也同时得到均衡改善 .     

SMA、OMMT对PA6/ABS共混物聚集态结构及性能影响的研究

采用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)等手段研究了苯乙烯-马来酸酐共聚物(SMA)、有机蒙脱土(OMMT)对尼龙6(PA6)/丙烯腈-丁二烯-苯乙烯(ABS)共混物体系聚集态结构及性能的影响.结果表明,SMA与OMMT的加入均可提高PA6/ABS共混物体系的强度及模量,但加入OMMT后共混物的韧性有所下降,而PA6/ABS/SMA共混物的韧性随SMA含量的增加呈上升趋势.SMA、OMMT对PA6/ABS共混体系都有细化ABS分散相的作用,随SMA加入量的增加,ABS分散相尺寸逐渐减小,分布趋于均匀;当OMMT加入量在4 phr以内时,对ABS分散相粒径影响不大,超过4 phr后,随着OMMT含量的增加,ABS分散相的尺寸逐渐减小.XRD与TEM的分析结果表明,对PA6/OMMT(100/5)共混物,OMMT主要以剥离形态分布,同时也存在少量OMMT聚集体;PA6/ABS/OMMT共混物中OMMT则基本以剥离形态选择分布在PA6基体相中.     

PTW对PA1010/PP共混物的增容作用

为了增加聚酰胺1010/聚丙烯(PA1010/PP)共混物的相容性,提高共混物的力学性能,采用一种新型的反应型增容剂乙烯-丙烯酸丁酯-甲基丙烯酸缩水甘油酯共聚物(PTW)进行增容,通过扫描电镜(SEM)、力学性能、傅里叶变换红外光谱(FTIR)和差示扫描量热(DSC)测试,研究了PTW对PA1010/PP共混物的增容作用.结果表明,随着PTW的加入,共混物的相区尺寸明显变小,当PA1010/PP/PTW质量比为70∶30∶7时,分散相尺寸细小而均匀,表明PTW有较好的增容作用.FTIR结果表明,PTW上的环氧基团和PA1010在熔融共混中发生了化学反应.DSC研究结果表明,PA1010的结晶温度随PTW的加入而降低,说明PTW对PA1010结晶有抑制作用.另外,PTW的加入使PP的结晶温度下降,当PTW质量分数为5%时出现2个结晶峰,即出现异相成核结晶和均相成核结晶,PP均相成核结晶的出现从另一个方面说明,在PA1010基体中分散相PP尺寸非常细小.当PTW质量分数为7%时共混物的力学性能最佳,干态冲击强度达到13.93kJ/m2,是未加增容剂时的2倍,拉伸和弯曲性能基本不变.PTW的增容机理在于其分子链中的甲基丙烯酸缩水甘油酯能与PA1010发生化学反应,而乙烯链段与PP有较好的亲和性,从而降低界面张力,减少相区尺寸,大幅度提高力学性能.     

马来酸酐接枝热塑性弹性体在PP/PA6共混物中的作用

研究了马来酸酐接枝热塑性弹性体 (TPEg )作为增容剂对聚丙烯 (PP) 尼龙 6 (PA6 )共混体系的相容性、相态以及物理力学性能的影响 .研究结果表明TPEg的加入大大改善了PP PA6共混体系的相容性 ,且随TPEg含量的增大分散相粒径明显降低 ,共混物的韧性以及延展性大大提高 ,同时拉伸强度及模量仍保持较好的水平 .TPEg增容的PP PA6共混物的非等温结晶行为的研究表明 ,共混物中PP和PA6的结晶行为不同于各自纯的聚合物 ,PA6作为成核剂使PP的结晶温度提高 ;而PA6由于TPEg的加入 ,出现分级结晶现象 ,一级结晶温度略低于纯PA6的结晶温度 ,且随TPEg含量增大结晶受阻 ,二级结晶温度与PP的接近 .由于PP、PA 6以及TPEg之间存在较强的相互作用 ,三元共混物中PP及PA6的玻璃化转变温度分别较其纯聚合物升高 .基于上述结果 ,提出了本共混体系的结构模型     

聚丁二酸丁二酯的无卤阻燃性能的研究

本文研究了聚苯基膦酸二苯砜酯(PSPPP)对聚丁二酸丁二酯(PBS)的阻燃作用。研究发现,在PBS中仅添加4wt%的PSPPP,其垂直燃烧就可以达到UL-94 V-0级,极限氧指数达到34,PSPPP对PBS表现出高效阻燃作用。然而,PSPPP对PBS有促进降解的作用,破坏了PBS的力学性能。通过在PBS/PSPPP体系中添加0.5wt%氧化锌后,有效抑制了PBS的降解,力学性能得到改善。     

Porous double-walled metal triazolate framework based upon a bifunctional ligand and a pentanuclear zinc cluster exhibiting selective CO2 uptake

The self-assembly of a custom-designed bifunctional ligand featuring both 1,2,3-triazolate and carboxylate donor groups with a pentanuclear zinc cluster generated in situ affords a double-walled metal triazolate framework (MTAF) material, MTAF-1 (Zn(5)(μ(3)-O)(2)(C(9)N(3)H(5)O(2))(5)(H(+))(4)(H(2)O)(17)(C(3)H(7)NO)(10)), which exhibits a surface area of 2300 m(2)/g and demonstrates interesting selective CO(2) uptake performances.     

Living radical polymerization of acrylates mediated by 1,3-bis(2-pyridylimino)isoindolatocobalt(II) complexes: monitoring the chain growth at the metal

A new type of mediator for cobalt(II)-mediated radical polymerization is reported which is based on 1,3-bis(2-pyridylimino)isoindolate (bpi) as ancillary ligand. The modular synthesis of the bis(pyridylimino)isoindoles (bpiH) employed in this work is based on the condensation of 2-aminopyridines with phthalodinitriles. Reaction of the bpiH protio-ligands with a twofold excess of cobalt(II) acetate or cobalt(II) acetylacetonate in methanol gave [Co(bpi)(OAc)], which crystallize as coordination polymers, and a series of [Co(acac)(bpi)(MeOH)], which are mononuclear octahedral complexes. Upon heating the [Co(acac)(bpi)(MeOH)] compounds to 100 degrees C under high vacuum, the coordinated methanol was removed to give the five-coordinate complexes [Co(acac)(bpi)]. The polymerization of methyl acrylate at 60 degrees C was investigated by using one molar equivalent of the relatively short-lived radical source 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (V-70) as initiator (monomer/catalyst/V-70: 600:1:1). The low solubility of the acetato complexes inhibits their significant activity as mediators in this reaction, whereas the acetylacetonate complexes control the radical polymerization of methyl acrylate more effectively. The radical polymerizations of the hexacoordinate complexes did not show a linear increase in number-average molecular weight (M(n)) with conversion; however, the polydispersities were relatively low (PDI=1.12-1.40). By using the pentacoordinate complexes [Co(acac)(bpi)] as mediators, a linear increase in M(n) values with conversion, which were very close to the theoretical values for living systems, and very low polydispersities (PDI<1.13) were obtained. This was also achieved in the block copolymerization of methyl acrylate and n-butyl acrylate. The intermediates with the growing acrylate polymer radical ((.)PA) were identified by liquid injection field desorption/ionization mass spectrometry as following the general formula [Co(acac)(4-methoxy-bpi)-(MA)(n)-R] (MA: methyl acrylate; R: C(CH(3))(CH(2)C(CH(3))(2)OCH(3))CN), a notion also confirmed by NMR end-group analysis.     

Thermal and physical properties of flame-retardant epoxy resins containing 2-(6-oxido-6H-dibenz〈c,e〉〈1,2〉oxaphosphorin-6-yl)-1,4-naphthalenediol and cured with dicyanate ester

2-(6-oxido-6H-dibenz(c,e)(1,2)oxaphosphorin-6-yl)-1,4-naphthalenediol (DOPONQ) was prepared by the addition reaction of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) with 1,4-naphthoquinone. The phosphorus-containing diol (DOPONQ) was used as a reactive flame retardant by an advancement reaction with the diglycidyl ether of bisphenol-A epoxy (DGEBA) resin at various stoichiometric ratios. DOPONQ-containing advanced epoxy was separately cured with various dicyanate esters to form flame-retardant epoxy/cyanate ester systems. The effect of the phosphorus content and dicyanate ester structure on the curing characteristic, glass transition temperature, dimensional stability, thermal stability, flame retardancy, and dielectric property was studied and compared with that of the control advanced bisphenol-A epoxy system. The DOPONQ-containing epoxy/cyanate ester systems exhibited higher glass transition temperatures as well as better thermal dimensional and thermal degradation stabilities. The flame retardancy of the phosphorus-containing epoxy/dicyanate ester system increased with the phosphorus content, and a UL-94 V-0 rating could be achieved with a phosphorus content as low as 2.1%.     

Highly stretchable and self-healing hydrogels based on poly(acrylic acid) and functional POSS

Herein, we present a novel way for the production of self-healing hydrogels with stretch beyond 4200% than their initial length and relatively high tensile strength(0.1?0.25 MPa). Furthermore, the hydrogel was insensitive to notch. Even for the samples containing V-notches, a stretch of 2300% was demonstrated. The hydrogels were developed by in situ crosslinking of the self-assembled colloidal poly(acrylic acid)(PAA)/functionalized polyhedral oligomeric silsesquioxane(POSS) micelles. This was achieved by the addition of functionalized polyhedral oligomeric silsesquioxane with tertiary amines and hydroxyls(POSS-AH) into the PAA reaction solution. The POSS-AH led to micellar growth, then the dualcrosslinked network was constructed. One type of crosslink was formed by hydrogen-bonding and ionic interactions between PAA chains and POSS-AH, the other type of crosslink was formed by covalent bonds between PAA and bis(N,N'-methylenebis-acrylamide).     

MgAlZnFe-CO3 LDHs对PBS膨胀阻燃体系性能的影响

采用恒定pH值共沉淀法在自制反应器中合成了不同原料配比的碳酸根型镁铝锌铁层状双羟基金属氧化物（MgAlZnFe-CO₃ LDHs）,并通过熔融共混MgAlZnFe-CO₃ LDHs、聚磷酸铵（APP）、三聚氰胺（MA）和全降解材料聚丁二酸丁二醇酯（PBS）制备出PBS膨胀阻燃材料. 采用傅里叶红外光谱（FTIR）、热失重（TG）、X射线衍射（XRD）、扫描电子显微镜（SEM）及元素分析（ICP）对MgAlZnFe-CO₃ LDHs进行了表征,并对PBS膨胀体系进行了力学性能和阻燃性能等测试. 结果表明,当Mg²⁺,Zn²⁺,Al³⁺和Fe³⁺的摩尔比为9：3：3：1时,合成的MgAlZnFe-CO₃ LDHs热稳定性最好,晶态结构规整,呈形貌规则的六边形片状;当MgAlZnFe-CO₃ LDHs的添加质量分数为1%时（阻燃剂的总添加质量分数为20%）时,PBS膨胀阻燃体系的极限氧指数（LOI）达到35%,垂直燃烧测试达到UL-94 V-0级别,力学性能得到较大改善. 实验结果表明,低添加量的MgAlZnFe-CO₃ LDHs与膨胀阻燃剂（IFR）协效阻燃PBS,一方面能够改善膨胀阻燃剂恶化PBS力学性能的现象,另一方面协同效应能够明显提高PBS的阻燃性能.     

Single-step preparation of topological gels using vinyl-modified β-cyclodextrin as a figure-of-six cross-linker

Herein, we have proposed a single-step preparation of topological gels using vinyl-modified β-cyclodextrin (V-β-CyD) and isoprene. Copolymerization of V-β-CyD and isoprene in an aqueous solution resulted in gelation due to V-β-CyD acting as a novel type of copolymer chain cross-linker. The vinyl moiety of V-β-CyD becomes a part of the copolymer, while the β-CyD moiety of V-β-CyD simultaneously incorporates the isoprene component of the copolymer. V-β-CyD is capable of two different modes of cross-linking at each end, i.e., chemically bonding and mechanically interlocking. Due to the shape of the cross-linking point, we refer to it as figure-of-six cross-linking. Nuclear magnetic resonance analysis showed that the gel contained V-β-CyD and isoprene in an approximately 1:0.3 stoichiometry. The relatively high content of β-CyD was reflected in the character of the gel; the gel swelled in dimethylformamide which is a good solvent of β-CyD. A fluorometric analysis using 6-(p-toluidino)-2-naphthalenesulfonic acid showed that the appended β-CyD was able to accommodate guest molecules. Introduction of an additional vinyl monomer into the gel was also successful. Addition of 4-vinylphenylboronic acid to the preparation procedure yielded a sugar-responsive gel that swelled in the presence of d-fructose.     

A Thermal study of the precipitates formed in ammonia neutralization of acidic solutions of dissolved phlogopite

The precipitates containing mainly iron, aluminium and magnesium hydroxides, obtained from phlogopite dissolved in nitric acid by means of the neutralization procedure with ammonia, have been investigated by thermal analysis (TG, DTG and DTA). According to the present study, which is part of a larger investigation into the chemical utilization of Finnish mica minerals, the formation of solid solutions between iron and aluminium hydroxides in silt increases with an increasing neutralization temperature. Nitrogen exists mainly in the form of nitrate in silts, and magnesium forms mixed hydroxides with aluminium, which causes a separation between the iron hydroxide and magnesium aluminium hydroxide phases.

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Zusammenfassung Die von in Salpetersäure gelöstem Phlogopit durch Neutralisierung mit Ammoniak erhaltenen, hauptsächlich Eisen-, Aluminium- und Magnesiumhydroxid enthaltenden Niederschläge wurden thermoanalytisch (TG, DTG und DTA) untersucht. In der vorliegenden Arbeit, die Teil einer grossangelegten Untersuchung zur chemischen Nutzung finnischer Glimmermineralien ist, wird gezeigt, dass die Bildung fester Lösungen von Eisen- und Aluminiumhydroxiden in Schluff mit zunehmender Neutralisationstemperatur ansteigt. Stickstoff kommt in Schluff hauptsächlich in Form von Nitraten vor, und Magnesium bildet Mischhydroxide mit Aluminium, was eine Trennung der Eisenhydroxidphase von der Magnesium-Aluminium-Hydroxidphase bewirkt.

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Hydrogen atom formation from the photodissociation of water ice at 193 nm

The TOF spectra of photofragment hydrogen atoms from the 193 nm photodissociation of amorphous ice at 90-140 K have been measured. The spectra consist of both a fast and a slow components that are characterized by average translational energies of 2k(B)T(trans)=0.39+/-0.04 eV (2300+/-200 K) and 0.02 eV (120+/-20 K), respectively. The incident laser power dependency of the hydrogen atom production suggests one-photon process. The electronic excitation energy of a branched cluster, (H(2)O)(6+1), has been theoretically calculated, where (H(2)O)(6+1) is a (H(2)O)(6) cyclic cluster attached by a water molecule with the hydrogen bond. The photoabsorption of this branched cluster is expected to appear at around 200 nm. The source of the hydrogen atoms is attributed to the photodissociation of the ice surface that is attached by water molecules with the hydrogen bond. Atmospheric implications are estimated for the photodissociation of the ice particles (Noctilucent clouds) at 190-230 nm in the region between 80 and 85 km altitude.     

Activation analysis of129I

Different methods (-, - and X-ray spectrometry, activation analysis, mass spectrometry) are reviewed for¹²⁹I determination in environmental samples. The sensitivities and the¹²⁹I/¹²⁷I ratios of the different methods are given. The influence of the¹²⁷I(n, )¹²⁸I(n, )¹²⁹I(n, )¹³⁰I reactions on¹²⁹I determination by activation analysis has been studied. A chart of optimal sample irradiation conditions is given.