端羟基聚丙烯酸酯分子量对PUA性能的影响

异佛尔酮二异氰酸酯(IPDI)、聚己内酯二醇(PCL)为主要原料合成聚氨酯预聚体,甲基丙烯酸甲酯和丙烯酸丁酯合成端羟基共聚物,两者共聚并在水中分散,得到丙烯酸酯改性水性聚氨酯(PUA)。PUA乳液形貌表征结果表明,当聚丙烯酸酯数均分子量达到9 041时,复合乳液的稳定性变差;复合乳液平均粒径随聚丙烯酸酯(PA)分子量增大而增加,但都小于150 nm,并呈现典型的核壳结构。FTIR测试表明,随着PA链段分子量增大,其氢键相互作用相对减弱。DSC测试显示在PA分子量较低时,PA和PU链段是相容的。TG和拉伸测试结果显示,PUA的热稳定性及力学性能都得到明显改善。     

Characterization of Radiation-Induced Thin Films of Urethane Oligomer

Forty different formulations were developed with urethane diacrylate (M1200) oligomers (containing an aliphatic backbone chain) in the presence of eight different functional monomer diluents additives and five co monomers (co additives). Thin films, prepared with these formulations under ultraviolet (UV) and electron beam (EB) radiations, were characterized. The theological properties were correlated with glass transition temperature (T _g) of the co monomer diluents. Results obtained with M1200 under UV and EB radiations are discussed and compared with those of aromatic urethane (M1100) films, previously reported.     

泛昔洛韦的合成

以2-氨基-6-氯嘌呤(2)为原料,在相转移催化剂四丁基溴化铵催化下与3-溴丙烷-1,1,1-三甲酸乙酯(3)缩合,得2-氨基-6-氯-9-(2,2-二乙氧羰基丁酸乙酯-4-基)嘌呤(4)。4用乙醇钠溶液脱羧得2-氨基-6-氯-9-(2-乙氧羰基丁酸乙酯-4-基)嘌呤(5)。5在AlCl3催化下,用NaBH4作还原剂还原得2-氨基-6-氯-9-(4-羟基-3-羟甲基丁基)嘌呤(6)。6在4-二甲基氨基吡啶(DMAP)催化下,与醋酐反应得2-氨基-6-氯-9-(4-乙酰氧基-3-乙酰氧基甲基丁基)嘌呤(7)。7在Pd-C催化下,氢化脱氯得泛昔洛韦(1)。以2-氨基-6-氯嘌呤(2)计总收率为55%。     

23例中药联合胰岛素治疗2型糖尿病的临床疗效分析

目的探讨中药联合胰岛素治疗2型糖尿病(T2DM)减低HbA1c的水平。方法对23例初诊T2DM患者作为联合组,采用中药联合胰岛素强化治疗,20例空腹血糖值相同者(对照组)单纯胰岛素治疗作为对照组,疗程3个月,采用SPSS16.0进行统计分析,比较2组在患病结局、血糖控制、糖化血红蛋白(HbA1c)水平之间的差异。结果治疗前2组空腹血糖和餐后2h血糖水平差异无统计学意义(P>0.05),治疗2周后差异有统计学意义(P<0.05)。治疗前2组HbA1c水平差异无统计学意义(P>0.05),治疗3个月后2组差异有统计学意义(P<0.05)。结论中药胰岛素治疗T2DM相比于单纯胰岛素治疗可获得更好血糖控制。     

The Chemistry of Chrome Mordanting of Wool

The chemistry of chrome mordanting is discussed under the headings: reaction of wool with chromium(VI) anions; reaction of wool with chromium(III) cations; reduction of chromium(VI) to chromium(IlI); interaction between chromium(Vl) and dye; interaction between chromium(III) and dye; and interaction between chromium(III), dye and wool.     

Effects of molding surfaces on the wettability of compression-molded polypropene films

Contact angles were measured for a series of compression-molded polypropene films blended with acrylic acid (AA) or maleic anhydride (MAH)/polyethylene oxide (PEO) (1 : 1) additives. The influence of different molding conditions concerning time and temperature as well as a coating of the aluminium foils used for the processing with polyethylene oxide (PEO) or polyvinyl pyrrolidone (PVP) were investigated. Films processed with uncoated aluminium foils showed, with one exception, no influence on contact angles with increasing molding temperatures and longer processing times. Upon coating the aluminium foils with hydrophilic substances the receding contact angles decrease by up to 60° with constant contact angle hysteresis. This behaviour corresponding to a permanent hydrophilization is attributed to chemical reactions of the coating with the functional groups of the additives.     

邻-间-对苯二酚固液平衡测定与关联

采用差示扫描量热法测定了邻苯二酚与间苯二酚、邻苯二酚与对苯二酚、间苯二酚与对苯二酚二元固液平衡数据,同时绘制出相应的简单低共熔型二元相图。低共熔组成和温度为：邻苯二酚(1) 间苯二酚(2),x1=0.5077,336.3K;邻苯二酚(1) 对苯二酚(3),x1=0.7879,365.8K;对苯二酚(3) 间苯二酚(2),x3=0.2305,366.1K。采用Wilson方程关联,标准偏差分别为0.48K,0.48K和0.56K。     

The effect of canal cleansing protocols on cementation of a fiber post to saliva-contaminated root canals

Objective: This study investigated the effect of saliva contamination and cleansing effect of a self-etching primer (SEP), phosphoric acid (PA), chlorhexidine (CHX), and ethanol (EtOH) on the microtensile bond strength (μTBS) of a fiber post cemented with a self-adhesive resin cement (SAC) to root canal dentin.

Material and methods: Sixty human lower premolar roots were randomly divided into 10 groups: (1) no saliva contamination, no cleansing (Control); (2) no saliva contamination, cleansing with SEP (NC-SEP); (3) no saliva contamination, cleansing with PA (NC-PA); (4) no saliva contamination, cleansing with CHX (NC-CHX); (5) no saliva contamination, cleansing with EtOH (NC-EtOH); (6) with saliva contamination, no cleansing (SC-NC); (7) with saliva contamination, cleansing with SEP (SC-SEP); (8) with saliva contamination, cleansing with PA (SC-PA); (9) with saliva contamination, cleansing with CHX (SC-CHX); (10) with saliva contamination, cleansing with EtOH (SC-EtOH). After cementation of posts, the roots were transversally sectioned to obtain six slices (n = 36) followed by μTBS test. Data were analyzed with ANOVA and Tukey HSD tests (p = 0.05).

Results: Saliva contamination and cleansing methods had a significant effect on μTBS values (p < 0.0001). All cleansing agents improved bond strengths when compared with Control and SC-NC. Cleansing with CHX and ethanol showed lower μTBS values than phosphoric acid and SEP, regardless of saliva contamination (p < 0.05).

Conclusions: Saliva contamination negatively affected bonding performance of SAC to root dentin. However; SEP, PA, CHX and EtOH can be used on contaminated dentin surfaces to optimize bonding performance of self-adhesive cements.     

含盐体系汽液平衡测定和关联

<正>含盐体系汽液平衡测定的主要困难是含盐液相的平衡组成分析.现有蒸馏法、物料衡算法、补偿法、化学分析法和色谱法.但各种方法一般都存在一些问题.蒸馏法和补偿法手续多,误差较大;色谱法中盐可能被带入色谱柱引起堵塞和腐蚀;化学分析法操作步骤多,有时盐不能完全电离;物料衡算法则需要知道釜体的汽相体积和汽相冷凝液的持液量,而这些因素较难确定准确.目前较多使用的还是物料衡算法.     

Effect of surface treatment of carbon fiber on the electrical and mechanical properties of high-impact polystyrene composite

Carbon fiber (CF), PU(polyurethane)-coated carbon fiber (CF-PU) and Ni-coated fiber (NCF) treated with a coupling agent (CA) were used to prepare composites for high impact polystyrene (HIPS) by melt blending. The optimum concentration of the titanate CA is 1.5 phf (per hundred parts of filler) when coupled with the carbon fibers. A composite prepared by adding a CA directly into the matrix which was then reinforced with fibers was investigated for comparison. These composites were evaluated for electromagnetic interference shielding effectiveness, dispersion, and adhesion between the polymer and the filler by means of scanning electron microscopy (SEM). The addition of CA generally improved the shielding effectiveness; this is especially apparent when the matrix was pretreated with CA before compounding with the fibers. The tensile properties were also improved upon CA addition.     

肟菌酯关键中间体的合成研究

以邻甲基苯乙酮为原料,依次经相转移催化下的高锰酸钾碱性氧化、甲醇酯化、甲氧胺盐酸盐肟化和N-溴代丁二酰亚胺（NBS）溴化后,得到制备肟菌酯的关键中间体——(E)-2-(2'-溴甲基苯基)-2-羰基乙酸甲酯-O-甲基酮肟。产品结构经熔点和1H-NMR表征。通过优化反应条件,总收率可达52%。     

Utilization of Recycled Polypropylene for Production of Eco-Composites

Renewable raw materials and recyclable thermoplastic polymers provide attractive eco-friendly quality as well as environmental sustainability to the resulting natural fiber reinforced composites. We studied the possibility of using the recycled polypropylene (PP) for production of composites based on kenaf fibers (KF) and rice hulls (RH) as reinforcements. Polypropylene/rice-hulls (PP/RH/CA) and polypropylene/kenaf (PP/K/CA) composites with 30% fiber (filler) content and appropriate compatibilizing agent (CA)—a maleic anhydride grafted PP (MAPP), have been prepared by two steps procedure: melt mixing and compression molding. Flexural strength and thermal stability of the composites with recycled PP were similar to those with neat PP. The composites reinforced with kenaf fibers have shown better properties than those based on rice hulls. The flexural strength of the composite sample with recycled PP is 51.3 MPa in comparison with 51.1 MPa for the composite with neat PP. Degradation temperatures of neat and composite with recycled PP at residual weight 90% are 344.4°C and 343.5°C, respectively. The results obtained report the possibility of utilization of recycled PP for the production of natural reinforcements based composites with good mechanical characteristics for using as construction building materials in housing systems.     

Suitability of TBA method for the evaluation of the oxidative effect of non-water-soluble and water-soluble rosemary extracts

The antioxidative effects of rosemary and grape-seed extracts spiked in human plasma were examined using the thiobarbituric acid (TBA) method. The TBA values of plasma spiked with reagents to generate reactive oxygen species, such as singlet oxygen ((1)O(2)), hydroxyl radicals ((·)OH), peroxynitrite (ONOO(-)), and superoxide anions (O(2)(·-)), were measured by a flow injection analysis method with fluorescence (FL) detection. TBA values obtained by the addition of 50 mg/mL of rosemary extracts for (1)O(2), (·)OH, ONOO(-), and O(2)(·-) increased to 964 ± 65%, 1063 ± 61%, 758 ± 78%, and 698 ± 41%, respectively (n = 3, P < 0.01), whereas the values with 1 mg/mL of grape-seed extracts or tocopherol decreased (40.2 - 66.3%). Furthermore, the antioxidative effects of rosemary extract in rat plasma, spiked with reagents to generate (·)OH, were examined by high-performance liquid chromatography with FL detection. No peak, other than TBA-malondialdehyde, could be detected using wavelengths of 532 (λ(ex)) and 553 nm (λ(em)).     

一种非索非那定关键中间体的合成研究

以4-（4-氯丁酰基）-α,α-二甲基苯乙酸甲酯（5）为原料,与4-氰基哌啶（4）缩合,再与二苯甲酮（2）反应得到了2-[4-[4-[4-（羟基二苯甲基）-1-哌啶基]-1-氧代丁基]苯基]-2,2-二甲基乙酸甲酯（1）,总收率约79％。该工艺反应条件温和,副反应少,易于操作,是一条适于工业化生产的合成路线。     

Controlled grafting of cellulose diacetate

Cellulose diacetate (CDA) was acylated with 2-bromoisobutyryl bromide (BriBr) or with dichloroacetyl chloride (ClAcCl) giving polyfunctional macroinitiators for ATRP grafting of styrene (St), MMA and butyl acrylate (BuA). Under various reaction conditions, macroinitiators with variable degrees of functionalisation could be prepared. The macroinitiators with 2-bromoisobutyryl (BriB) groups were grafted with St or BuA, those with dichloroacetyl (ClAc) functions were used for graft copolymerization of MMA. Graft copolymers with chemically different grafts as well as tunable lengths and densities of grafts were synthesized in this way. Poly(CDA-g-St) and poly(CDA-g-MMA) were further used as macroinitiators of BuA polymerization, giving poly[CDA-g-(St-b-BuA)] and poly[CDA-g-(MMA-b-BuA)] graft copolymers with diblock grafts.     

高纯度叶黄素的制备及稳定性研究

金盏菊萃取物20g,加入正丁醇40mL,密封搅拌均匀后(55℃),加入维生素C0 2g,再加入40mLw(NaOH)=20%的水溶液在70℃进行皂化反应8h。皂化物中加入400mL水,搅拌均匀后,过滤,得到叶黄素,w(C40H56O2)=94%。将其用V(CH2Cl2)∶V(CH3OH)=2∶1结晶,叶黄素质量分数可提高至w(C40H56O2)=98%,抗氧化剂、温度、光、氧气对叶黄素的稳定性具有重要影响。     

比沙可啶的合成工艺研究

以2-吡啶甲醛为起始原料,在浓硫酸催化下,与苯酚缩合得到4,4'-二羟基二苯基-(2-吡啶)-甲烷和2,4'-二羟基二苯基-(2-吡啶)-甲烷,利用二者在乙酸乙酯中溶解度的差别,分离得到4,4'-二羟基二苯基-(2-吡啶)-甲烷,用氢氧化钠转变得到酚钠盐后,经乙酰化得到比沙可啶。其结构经核磁共振氢谱确证,纯度经液相色谱分析为99%。改进后的合成工艺操作简便,收率可达58%。     

The miscibility of polyacrylates and polymethacrylates with PVC: An interpretation of the heats of mixing of oligomers

Oligomers of various polyacrylates and polymethacrylates and a chlorinated paraffin (as an analogue for PVC) were studied in order to give information relevant to the miscibility of the respective polymers. The heats of mixing of the oligomers with the chlorinated paraffin were measured and showed that those oligomers with the lowest and highest ester group concentration (poly(methyl acrylate) and poly(octadecyl methacrylate)) had unfavourable (positive) heats of mixing whereas oligomers with intermediate ester group concentrations had favourable (negative) heats of mixing. This was consistent with the miscibility of the respective polymers in most cases. The results were interpreted in terms of the summation of the effects of the specific interactions and the dispersive forces. A high concentration of interacting groups leads to a high contribution from the specific interaction, but in the case of poly(methyl acrylate) with the highest concentration of interacting groups this is outweighed by a large unfavourable contribution from the dispersive forces.     

增强相对热塑性聚酰亚胺复合材料性能的影响

采用热模压成型的方法,在热塑性聚酰亚胺(TPI)中添加玻璃微珠(GB)、玻璃纤维粉(GFP)和短切玻璃纤维(SGF)进行复合增强,研究了3种不同形态填充材料及其含量对复合材料力学、摩擦磨损及热性能的影响。结果表明,随着填充物填充量的增加,所制得复合材料的刚性明显提高;并且填充物长径比越大,其作用效果越明显,由此制得的复合材料同时具有较低的体积磨损率及线膨胀系数。采用SGF增强复合材料的力学强度也随其填充量的增加显著增大,而采用GB及GFP填充的材料则呈下降趋势。采用SEM观察了复合材料断裂面的结构形貌,初步分析了其增强机理。     

氟噻草胺的合成

改进了除草剂氟噻草胺的合成方法。以肼基二硫代甲酸甲酯、三氟乙酸为原料合成2-甲砜基-5-三氟甲基-1,3,4-噻二唑(4),反应收率81.5%;以对氟硝基苯、丙酮经过催化加氢、酰化、醇解合成N-(4-氟苯基)-N-异丙基-2-羟甲基乙酰胺(8)。化合物(4)与(8)反应合成氟噻草胺,得率94.2%。改进后的工艺反应条件温和,三废少,产品纯度和收率高。