聚氯乙烯增塑糊流变行为研究——Ⅲ、稀释剂和分散剂的影响

以石油溶剂为稀释剂,4-甲基-2-戊酮(Ⅰ)和2-乙氧基乙醇(Ⅱ)为分散剂,研究了不同PVC树脂增塑糊的粘度特征。结果表明,由于PVC是极性聚合物,分散剂的分散效果主要决定于它的极性,Ⅰ的分散效果优于Ⅱ。若PVC含有聚氧乙烯基型表面活性剂,其糊用PVC树脂颗粒能较好地分散。     

新型增塑剂二甘醇二苯甲酸酯的合成

以钛酸四丁酯为催化剂合成具有优良性能的增塑剂二甘醇二苯甲酸酯(DEDB)．通过实验确定了合成DEDB的适宜工艺条件：二廿醇1 mol，苯甲酸2．1mol,钛酸四丁酯3．2g，应时间4h，反应温度190℃，在此条件下产率呵达98．5％以上。     

增塑剂法研究高分子共混物的相平衡曲线

经共聚改性的聚苯乙烯PS(OH)与聚甲基丙烯酸丁酯PBMA形成的互溶体系具有LCST行为。由于体系的玻璃化温度较高。分相温度与玻璃化温度接近。使分相时的浊点温度受升温速率影响很大,以致浊点曲线与相平衡曲线有一定的差距。本文以邻苯二甲酸二丁酯DBP为增塑剂加入PS(OH)/PBMA共混体系中,在一定的升温速率下测浊点温度,并对增塑剂作零浓度的外推,由此得到的浊点曲线与相平衡曲线完全一致。证实了增塑剂法的可靠性。加入增塑剂后浊点温度随升温速率变化平缓,更接近相平衡点,显示了增塑剂法的有效性。     

Plasticizing and thermal stabilizing effect of bio-based epoxidized cardanol esters on PVC

Poly(vinyl chloride) (PVC) is a widely used plastics in different industries. It is an intrinsically hard and brittle polymer and requires the use of plasticizers to improve the processability. Commonly used phthalate-based plasticizers have serious toxicity issues and we present alternatives based on epoxidized soybean oil (ESO) and epoxidized cardanol esters (ECEs). ECEs are synthesized from cardanol and three fatty acids (oleic, ricinoleic, and myristic) using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) as a coupling agent. Their structure and purity are confirmed by Fourier transform infrared spectroscopy (FTIR) and Nuclear magnetic resonance. Moreover, plasticized PVC films are prepared using a solvent-free method. The replacement of 10 phr of ESO with 5 phr of ECE improves the plasticizing power due to the co-solvency effect. Mechanical properties and thermal stability of plasticized PVC films are correlated with the chain length and the number of epoxy groups in ECE. The best plasticizing effect is observed for epoxidized cardanol-myristate (ECD-MA). ECD-MA as a shorter-chain secondary plasticizer is more compatible with ESO and allows higher conformational mobility of PVC chains. PVC/30ESO/5ECD-MA polymer exhibits an exceptionally high initial thermal decomposition temperature (314.4°C) while preserving moderate ductility and tensile strength (263.4% and 23.3 MPa). Overall, this study highlights the potential applicability of ECD-MA in combination with ESO as a sustainable, bio-based plasticizer and heat stabilizer for flexible PVC products.     

Fabrication of Sensitive Membrane Electrodes and their Application in Electrochemical Quantification of Ibandronate in Dosage Form

A new, highly selective, simple and accurate method was adopted and validated for the direct quantification of ibandronate sodium monohydrate (IBN) in tablets using sensitive polyvinyl chloride membrane electrodes. Three membranes were fabricated using dibutyl sebacate, nitrophenyl octyl ether and dioctyl phthalate. The fabricated electrodes showed fast response, capability of application in wide pH range and direct determination of IBN in turbid solutions. The most important advantage of the proposed analytical method is that it successfully allows direct determination of IBN in dosage form. The proposed analytical methodology can be applied for the direct quantification of IBN in pharmaceutical formulations.     

新一代环保型增塑剂柠檬酸三丁酯绿色合成进展

 柠檬酸三丁酯是一种无毒、绿色环保型的增塑剂,是替代目前广泛使用的有毒增塑剂的新一代环保型增塑剂之一。概述了柠檬酸三丁酯的主要性质及主要合成方法,对可用于制备柠檬酸三丁酯的固体酸催化剂进行了分类,总结了其在酯化反应中的应用。分析认为,有机固体酸催化剂是制备柠檬酸三丁酯的合适催化剂。     

Thermal stability of poly(vinyl chloride) with epoxidised soybean oil as primary plasticizer

Epoxidised soybean oil (ESBO) has been tested as a primary plasticizer in suspension PVC. The stabilization of the material with different traditional stabilizers has been evaluated and compared to a compound with PVC-ESBO only. Surprisingly, the addition of stabilizers seems to decrease the stability of PVC-ESBO. Traditional stabilizers, for instance Ca/Zn-stearate have been evaluated as well as metal carboxylates regarding yellowness index and UV-Vis absorption. Among the metal carboxylates, a decrease in initial discolouration, i.e. yellowness was observed with addition of Zn-stearate whereas the addition of Al-stearate improved the colour after ageing compared to PVC-ESBO without stabilizer.The stabilizing mechanism of ESBO itself, without the addition of stabilizers, has also been investigated. Analyses with ion chromatography of ESBO extracted from PVC samples without stabilizer revealed that the chlorine content of ESBO had increased when ageing the sample. MALDI analysis revealed that hydrochloric acid likely had attached to the ESBO. Reactions between ESBO and PVC were found through NMR analysis.     

活化煤矸石对减水剂塑化效果的影响

试验研究了经活化处理并磨细的煤矸石(AG)以不同比例等量替代部分水泥后,对掺减水剂水泥净浆流动度的影响规律,并将AG与常用的活性矿物掺合料矿渣粉(Slag)、高钙粉煤灰(HCFA)进行比较.结果表明,所选用的三种品牌硅酸盐系列水泥和三类减水剂,用AG等量替代部分水泥均会对减水剂的塑化效果产生负面影响;与此相反,Slag和HCFA有助于改善减水剂的塑化效果.初步分析了AG,Slag和HCFA等矿物掺合料对减水剂塑化效果的影响机理.     

First-principles hybrid functional study of the electronic structure and charge carrier mobility in perovskite CH_3NH_3SnI_3

We calculate the electronic properties and carrier mobility of perovskite CH_3NH_3SnI_3 as a solar cell absorber by using the hybrid functional method. The calculated result shows that the electron and hole mobilities have anisotropies with a large magnitude of 1.4 × 10~4cm~2·V~(-1)·s~(-1) along the y direction. In view of the huge difference between hole and electron mobilities, the perovskite CH3NH3 Sn I3can be considered as a p-type semiconductor. We also discover a relationship between the effective mass anisotropy and electronic occupation anisotropy. The above results can provide reliable guidance for its experimental applications in electronics and optoelectronics.     

超临界流体色谱同时测定运动饮料中的8种邻苯二甲酸酯类增塑剂

建立了同时快速测定运动饮料中邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二丙酯、邻苯二甲酸二丁酯、邻苯二甲酸二戊酯、邻苯二甲酸丁基苄基酯、邻苯二甲酸二（2-乙基己基）酯、邻苯二甲酸二辛酯8种邻苯二甲酸酯（PAEs）类增塑剂的超临界流体色谱-紫外检测分析方法。实际样品经液相萃取后,用超临界流体色谱分析,以超临界态二氧化碳-3%（体积分数）甲醇作为色谱流动相进行等度洗脱,检测波长为225 nm,6 min即可实现分离。8种PAE类增塑剂在0.05~25 mg/L范围内均具有良好的线性关系,相关系数为0.9991~0.9997,方法检出限为7.5~15 μg/L。8种PAE类增塑剂在运动饮料样品中的加标回收率为91.7%~100.2%,相对标准偏差均不大于6.5%（n=3）。应用该方法对多种市售运动饮料中的8种PAE类增塑剂进行检测,结果表明,该方法环保、快速、灵敏、选择性高、结果准确,能满足运动饮料中增塑剂含量检测的要求。