己二酸改性二聚酸酰胺尼龙共聚物的制备与表征

以己二酸己二胺盐、二聚酸为原料,采用熔融缩聚方法制备了系列短链己二酸改性的二聚酸酰胺尼龙共聚物。考察了己二酸对二聚酸酰胺尼龙(DAPA)凝聚态结构、热性能的影响,对共聚物进行了表征。结果表明,己二酸的加入可促进DAPA从γ到α、β晶型的晶相转变,并提高其结晶程度,还可通过刚性分子骨架和N-Hσ-轨道与C=Oπ*-轨道的σ-π*-超共轭效应对共聚物分子间缔合氢键的数量、电子离域方向和离域程度的调变作用提高酰胺基团的活性,对酰胺基团有活化作用,从而恶化DAPA的热稳定性。     

磁鼓清洁刮板用新型低硬度TPU的研究

以聚己内酯二醇、4,4－二苯基甲烷二异氰酸酯、1,4-丁二醇及二异氰酸酯二聚体等为原料,合成了含脲二酮环的新型热塑性聚氨酯弹性体（TPU）该TPU可在热成型过程中交联。对该类弹性体和其它聚氨酯弹性体的物理性能做了分析和比较。实验表明,一种含脲二酮环的新型TPU的性能符合磁鼓清洁刮极性能要求。     

酞菁铕及其C_(60)共混复合体系的发光特性研究

本文合成了稀土酞菁铕二聚体（ＨＥｕＰｃ２）,并对其发光特性进行了研究,发现晶型和溶剂对ＨＥｕＰｃ２的荧光特性影响较大;在２７５．５ｎｍ的紫外光激发下,晶型ａ的ＨＥｕＰｃ２在ＤＭＦ溶剂中可在６１５ｎｍ附近发出高亮度的红光。对ＨＥｕＰｃ２／Ｃ６０共混复合体系的荧光和紫外谱图分析发现Ｃ６０对ＨＥｕＰｃ２起猝灭作用。     

Alkyl ketene dimer modification of thermomechanical pulp promotes processability with polypropylene

Alkyl ketene dimers (AKDs) are known to efficiently react with cellulose with a dual polarity in their structure: a polar component and a nonpolar component. AKD of three different carbon chain lengths, 4, 10, and 16 carbons have been synthesized, and thermomechanical pulp (TMP) fibers were modified by them. The modification of TMP fibers with AKD resulted in an increased water contact angle, showing the presence of the AKDs on the TMP fibers and a new carbonyl peak in the IR spectra, suggesting modification of the TMP fibers with AKD groups. Calculating the Hansen solubility parameters of AKD and AKD conjugated to TMP in polypropylene (PP) indicates improved compatibility, especially of longer chain AKD and TMP AKD. The rheological studies of the composites showed that the AKD with the longest carbon chain decreases the melt viscosity of the PP-TMP-AKD composite, which combined with the shape and the color of the extruded composite filaments indicates improved flow properties and reduced stress build up during processing. The research findings demonstrate the ability of AKD to enhance the dispersibility and compatibility of natural fibers with PP.     

两种势下的Si(100)表面重构及二聚体形成过程的分子动力学模拟

分别采用Tersoff势与S-W势对不同温度下Si(100)面重构情况进行分子动力学模拟,找出了这两种势函数下发生重构的温度范围,进而采用S-W势对几种典型情况进行模拟研究.结果发现,二聚体形成前后的温度、内能会出现明显变化,高温时重构速度快但效果较差且不稳定,会形成吸附单体.原子间距为0.33nm左右是二聚体形成的关键距离.     

印刷油墨用醇溶性聚酰胺树脂的研制

介绍了一种由二聚酸和二元胺为主要原料制备而成的醇溶性聚酰胺树脂。通过共缩聚反应制备聚酰胺树脂的方法,探讨了配比及反应条件等对树脂性能的影响。结果表明:该聚酰胺树脂具有较好的醇溶性、抗凝胶性能以及凝胶恢复性能等特点,在作为塑印油墨的连接料时尤为适用。     

油酸封端的C36二聚酸/PEG/PPG聚酯的合成及其消泡抑泡性能

采用C36二聚脂肪酸为原料,与聚乙二醇(PEG)和聚丙二醇(PPG)缩聚后,用油酸封端,合成了聚酯型高分子表面活性剂,研究了反应物摩尔比、反应温度、反应时间、催化剂及带水剂用量对产物的消泡和抑泡性能的影响。结果表明,较佳反应条件为:n(C36二聚酸)∶n(油酸)∶n(PEG)∶n(PPG)=0.035∶0.020∶0.030∶0.020,180℃下反应2.5 h,二聚酸用量为19.6 g时,催化剂对甲苯磺酸用量为0.3 g,带水剂甲苯用量为15 mL。与商品有机硅及复配型的聚醚类消泡剂比较后发现,所合成的聚酯水基消泡剂具有更好的消泡和抑泡性能。     

粉煤灰-水泥水化的核磁共振定量分析

利用高分辨固体核磁共振仪结合去卷积技术,定量分析了粉煤灰水泥浆体中水泥和粉煤灰的水化程度以及C-S-H凝胶中硅氧-铝氧链平均长度,同时研究了粉煤灰火山灰反应对C-S-H结构的影响。结果表明:水化3 d时,系统中约47%的水泥和14%的粉煤灰参与了水化反应,C-S-H平均链长为3.2;水化120d时,水泥和粉煤灰的水化程度分别为89%和33%,C-S-H平均链长约为3.8,远大于纯水泥浆体中C-S-H的平均链长(为2.7)。水化3 d时粉煤灰玻璃相结构中的Si—O—Si,Si—O—和Al—Al共价键断裂,形成了单体硅酸根和单体铝酸根,这些单体结构桥连体系中的二聚体单元进而提高了C-S-H平均链长。粉煤灰掺入并不会因为C-S-H聚合度提高以及ACL增加就能促进粉煤灰水泥浆体强度。     

Characterization of Pozzolanic Reaction and Its Effect on the C-S-H Gel in Fly Ash-cement Paste

High resolution solid-state 29Si MAS NMR,combined with XRD,SEM and FTIR were used to characterize the pozzolanic activity of FA,type of main pozzolanic reaction products,and the effect of pozzolanic reaction on the C-S-H microstructure in fly ash-cement (FC) paste.The experimental results indicate that in the hydrated FC paste with 30% dosage of FA at 3 d,FA partially participated in the pozzolanic reaction,while,at 120 d,FA largely reacts.During the hydration of FC paste at laboratory temperature,the pozzolanic reaction products are C-S-H gel rather than zeolitic gel.Moreover,after the covalent bonds of Si-O-Si,Si-O-Al and Al-O-Al in the structure of FA are broken,monosilicates Si-OH and Al-OH groups form,these chemical species can connect C-S-H dimers,thus producing more Al-free C-S-H and aluminous C-S-H than in the plain cement paste.The increased content of Al for Si substitution in the bridging tetrahedra of C-S-H may decrease the stability of C-S-H,which results in a rather obvious loss in the mechanical strength of hardened FC paste.     

New steroid dimer derived from cholic acid as receptor for lanthanum(Ⅲ) and calcium(Ⅱ) nitrates

New steroid dimer,ethylene bridged bis-carbamate(3) was synthesized from cholic acid in few steps. Complexes of 3 with lanthanum(Ⅲ) and calcium(Ⅱ) nitrates were prepared in reaction of 3 and appropriate metal salts. They were characterized by spectral data(Infrared(IR) ,ultraviolet-visible(UV/Vis) ,nuclear magnetic resonance(NMR) spectroscopy and fast-atom bombardment(FAB) ,electrospray(ESI) and matrix-assisted laser desorption/ionization mass spectrometry(MALDI-MS)) and elemental analysis. The similarity in complexing behavior of steroidal dimer toward calcium and lanthanum ions was observed.