无规共聚物P(AA-co-BA)的制备及表面活性研究

研究无规共聚物P(AA-co-BA)作为高分子表面活性剂的可行性。以丙烯酸(AA)和丙烯酸丁酯(BA)为单体,采用自由基溶液聚合法成功制备了5种投料比的无规共聚物P(AA-co-BA),其热稳定性良好。研究比较了表面张力法和电导法对该聚合物临界胶束浓度(cmc)的测试,结果表明,两种方法在测试聚合物cmc时结果一致,电导法虽简便,但表面张力法更适合进行物质的表面活性研究。当单体投料比m(BA)∶m(AA)=1∶10～1∶5时,聚合物的cmc为0.6～0.9?g/L,对应的表面张力为44.8～49.5?mN/m,这表明适当投料比的无规共聚物P(AA-co-BA)可以作为高分子表面活性剂。     

甘露醇酸碱中和滴定法快速测定肥料中的硼

采用国家标准方法甲亚胺-H酸分光光度法测定肥料中的硼,具有较高的准确度,但显色时间长,不便于快速测定。采用甘露醇酸碱中和滴定法测定肥料中的硼,对样品处理简单,比国家标准检测方法省时,且测定值与国家标准方法所测值基本一致。该法精密度、准确度较高,硼的加标回收率在98.0%以上。     

间接酸碱滴定法快速测定钡含量

研究了酸碱滴定法间接测定钡含量的方法.方法基于被测Ba2+与定量的K2CrO4溶液反应形成BaCrO4沉淀,剩余的CrO2-4以溴甲酚绿为指示剂,用HCl标准溶液滴定而间接测定钡.方法简便快速,应用于钡盐及重晶石中钡的测定,结果满意.     

酸碱滴定法快速测定萃取料浆中五氧化二磷含量

通过在试液中加入中性盐,选用合适的指示剂,采用酸碱滴定法快速测定萃取料浆中五氧化二磷含量,其准确度可以满足生产要求。     

酸碱中和滴定法测定磷铁中磷的方法讨论

本文对酸碱中和滴定法测定磷铁中的磷的主要条件及效果进行试验,采用酸溶-碱回收的方法溶解试料,磷钼酸铵沉淀后酸碱滴定法测定磷含量。对试样分解条件、沉淀条件、过滤条件等进行了分析和讨论,并进行了实际样品的验证试验,试验结果表明该方法测定的灵敏度、准确度、精密度均能满足磷铁中磷的日常检验分析的要求。     

苯乙烯—马来酸酐无规共聚物中酸酐含量的测定

对苯乙烯(St)-马来酸酐(MAH)无规共聚物(SMA)中MAH及马来酸含量的分析方法作了较为详细的研究,确定了一种新的分析方法,即以丁酮为溶剂,加入水解催化剂及水,用KOH-乙醇溶液滴定至终点,测得总酸值(B);以丁酮为溶剂,用KOH-乙醇溶液直接滴定,测得总酸值(A)。样品中MAH质量含量等于(B-A)×MAH分子质量(M_(MAH))×10~(-1),马来酸质量含量等于(A-B/2)×马来酸分子质量(M_(马来酸))×10~(-1)。由滴定分析结果证实了这种分析方法是可行的。     

酸碱滴定法测定葡萄糖氯化钠注射液中氯化钠不确定度评价

对葡萄糖氯化钠注射液中氯化钠的含量进行不确定度评价。建立评价酸碱滴定法测定葡萄糖氯化钠注射液含量不确定度的数学模型,对测定中的各影响因素进行考察。结果表明,氯化钠的扩展不确定度为0.004%,含量测定结果为(0.890±0.004)%。建立的计算方法实用、可靠,可以用于酸碱滴定法测定药物含量的不确定度评定。     

中职药检专业酸碱滴定法中信息化技术的应用 ——以阿司匹林的含量测定为例

用酸碱滴定法测定阿司匹林的含量是分析化学中酸碱滴定法的一个重要实验内容,本文主要讲述了针对中职学生的特点,用信息化教学手段如何将本次实验课程达到良好的教学效果。     

茂金属乙烯/苯乙烯假无规共聚物(ESI)的研究进展

乙烯／苯乙烯假无规共聚物（ESI）是一类新型的茂金属聚合物，通常苯乙烯质量分数可达80％，随苯乙烯的质量分数增加，ESI由半晶态的弹性体材料过渡到非晶态的热塑性塑料，笔者综述了近年来国外茂金属乙烯－苯乙烯假无规共聚物（ESI）研究与开发的新进展，重点介绍了ESI的物理性能，合成工艺，共混性能，填充性能，膜塑性能及发泡性能，并论述了ESI的应用现状和发展趋势。     

亚硫酸钠酸碱滴定法测定三聚氰胺泡沫中甲醛释放量

介绍了对三聚氰胺泡绵中甲醛释放量的一种新的定量方法——亚硫酸钠酸碱滴定法,此法在耗时、成本和环保上均优于乙酰丙酮分光光度法.     

Nanostructured morphology of a random P(DLLA-co-CL) copolymer

The random architecture of a commercial copolymer of poly(DL-lactic acid) and poly(ε-caprolactone), poly(DL-lactide-co-caprolactone), has been characterized by chemical structure analysis from hydrogen-1 nuclear magnetic resonance results. Moreover, spherical nanodomains have been detected in the thin films of this copolymer obtained after solvent evaporation. These nanodomains studied by atomic force microscopy and transmission elecron microscopy grow progressively under annealing until they collapse and form a homogenous disordered structure. This is the first time that the nanostructure of random poly(DL-lactic acid)/poly-(ε-caprolactone) copolymers is revealed, representing one of few experimental evidences on the possible nanostructuration of random copolymers.     

碱滴定法测定氰尿酸纯度方法的改进

以酸碱滴定返滴法测定氰尿酸的纯度,以质量分析法作为参照,并与常规碱滴定法作了比较。结果表明,用酸碱滴定返滴法测定结果的重复性和准确度均较好。     

Effect of composition of added random copolymer on the phase behavior of block copolymer

Blends of styrene-butadiene diblock copolymer (S-B, 52 wt% styrene content) and styrene-butadiene random copolymer (SBR) of various styrene compositions were studied by small-angle X-ray scattering, light scattering, and transmission electron microscopy. The composition of random copolymer plays an important role in the solubilization of SBR in S-B. The order-disorder transition temperature, T_ODT, decreases linearly with the addition of SBR. T_ODT decreases as the symmetry in SBR composition increases and shows the highest value in the case of homopolymers. Asymmetric butadiene-rich SBR dissolves mostly into PB microdomain of S-B to increase lamella microdomain spacing, D, and its addition makes the overall microdomains of S and B in the mixture more asymmetrical. Symmetric SBR is localized into the interface of S-B microdomain to reduce unfavorable S-B contact at the interface. The phase diagram for S-B containing asymmetric SBR shows a succession of mixed mesophases of different morphologies from lamellae and cylinder to disordered liquid phases, whereas the phase diagram containing symmetric SBR shows two homogeneous phases and one region of two-phase coexistence, where macroscopically separated phases coexist together.     

CTFE与VAc共聚物的制备

在超临界CO2中制备三氟氯乙烯(CTFE)与乙酸乙烯酯(VAc)共聚物P(CTFE-co-VAc),考察了单体配比对聚合反应、产物结构及性能的影响,研究了共聚物的表面性能及其溶液黏度。控制单体配比可得到不同结构、不同氟含量的共聚物。当m(VAc)/m(CTFE)小于4∶16时,产物中y(CTFE)恒定在50%左右;氟含量是影响共聚物表面性能的关键因素,共聚物中CTFE单元的比例增加,则产物中氟含量增大,产物对溶剂的接触角变大,当产物中w(F)为29.16%时,聚合物膜的表面能最小,为0.028 J/m2;聚合物溶液黏度随共聚物中VAc结构单元比例增加而增大。     

酸催化甘油醚化合成甘油烷基醚反应的研究

以甘油和异丁烯为原料合成甘油烷基醚,考察阳离子交换树脂Amberlyst-15(dry)、Amberlyst-35(dry)、DFHS-6、分子筛H-Y(6)、ZSM-5(25)、H-Beta(15)及PTSA(对甲苯磺酸)等7种酸性催化剂以及催化剂用量、反应温度、搅拌转速、甘油/异丁烯摩尔比、反应时间、反应压力对反应的影响。结果表明,最佳催化剂为Amberlyst-35(dry),最佳工艺条件为:反应时间5 h,反应温度90℃,甘油/异丁烯摩尔比1∶4,反应压力3 MPa,搅拌转速500 r/min,催化剂用量为甘油质量的7%。在此条件下,甘油转化率可达96.4%,醚类化合物收率达77.4%。     

异丁烯-co-对甲基苯乙烯的合成研究

以二枯基氯(DCC)、四氯化钛(Ti Cl4)、2,6-二叔丁基吡啶(Dt BP)为合成原料,通过活性正离子聚合成功地合成了不同异丁烯和对甲基苯乙烯进料比、不同聚合时间下的聚(异丁烯-co-对甲基苯乙烯)无规共聚物。通过TG以及DSC对产物进行表征。结果表明,无规共聚物的单体转化率与分子量呈线性关系,分子量分布窄,具有活性聚合的特征。     

Preparation of temperature-sensitive P (CS-g-TMSPM-g-NIPAAm) copolymer using a chemical cross-linking method

A novel thermosensitive P (CS-g-TMSPM-g-NIPAAm) copolymer film was synthesized through grafting thermosensitive monomer N-isopropyl acrylamide (NIPAAm) onto the beforehand modified chitosan (CS) by cross-linking agent 3-trimethoxysilypropyl methacrylate (TMSPM). Fourier transform infrared spectroscopy confirmed the successful polymerization of NIPAAm with CS-g-TMSPM, and its lower critical solution temperature was measured at 34°C. Although osteoblasts and adipose-derived stem cells showed excellent growth state on the film in vitro, only osteoblasts demonstrated good adhesion and stretch probably because of the necessary specific cell–film interplay. Hence, for specific cell cultures and nonenzymatic harvesting in vitro, the prepared thermosensitive film could be a promising approach.     

可生物降解P(BS-co-CL)的合成

将不同配比的1,4-丁二酸、1,4-丁二醇与己内酯(ε-CL)在氯化亚锡和对甲基苯磺酸的催化作用下进行熔融缩聚合,合成了可生物降解聚丁二酸丁二酯-聚己内酯共聚物[P(BS-co-CL)]。采用核磁共振波谱仪、差示扫描量热仪、广角X射线衍射仪、偏光显微镜等对P(BS-co-CL)的结构、结晶性能、晶体形态和力学性能进行了分析。结果表明:引入ε-CL降低了聚丁二酸丁二酯(PBS)的结晶能力,改变了PBS的结晶形态,但晶体结构未发生改变,仍为单斜晶系α晶型。适当含量ε-CL的引入显著提高了P(BS-co-CL)的拉伸弹性模量和断裂拉伸应变。     

电位滴定法在标定标准滴定溶液中的应用

探讨用自动电位滴定仪标定标准滴定溶液,并与国家标准中以指示剂判定滴定终点的方法进行了比对。结果表明,自动电位滴定法标定EDTA、硝酸银标准滴定溶液,滴定结果准确度高,数据重现性高于标准法,可满足化验室分析工作的需要。     

Spectroscopic determination of copolymer composition in high isocyanate content polymers

Copolymer compositions high in aliphatic isocyanate content cannot be determined by typical titration methods due to crosslinking during polymer workup. A quantitative method involving ultraviolet analysis of an isocyanate/absorbing amine adduct is presented. Agreement between the ultraviolet (UV) method and elemental analysis, in both composition data and reactivity ratios (r₁r₂, which are calculated from data obtained by the UV method) delineate a viable method of polymer analysis. Data from Fourier transform infrared (FTIR) analysis of the urea linkage is in good agreement with nitrogen analysis and the UV method, but is sufficiently biased to cause significant differences in r₁r₂ values. Bias in the infrared analysis may arise from the intra- or intermolecular interaction of CO and N H groups of the urea linkage. Hypochromic effects are observed in UV analysis in noncarbonylic solvents. Hypochromicity varied with copolymer composition and could be related to sequence distributions. The hypochromic effects observed were most pronounced in low amine adduct content polymers where the majority of phenyl chromophores are isolated between MMA units.