STUDIES ON TUNG OIL COATED REGENERATED CELLULOSE FILMS WITH WATERRESISTANCE

Regenerated cellulose films with water-resistance were obtained by an improved method ofpreparing cellulose cuoxam solution from pulps of agricultural wastes (linters, wheat straw, reedand Bamao). Experimental results showed that the mechanical properties of both the dry. and wetfilms were excellent. Data from IR, SEM and tensile strength measurements implied that thesignificant improvement of water-resistance of the films was due to the cohesion between the thinTung oil covers with hydrophobicity and the regenerated cellulose films. The films werecompletely biodegraded after being buried in soil for 100 days. The transmittance of the filmsderived from linter and reed in visible band range were 80-90%.     

GC-MS Analysis of the Essential Oil from the Oleoresin of Pistacia atlantica var. mutica

The oleoresin of Pistacia atlantica var. mutica, growing in different regions of Iran, is a popular naturally occurring chewing gum and has been used traditionally in the treatment of peptic ulcer. The GC-MS analysis of the essential oil, obtained from steam distillation of the oleoresin of P. Atlantica var. mutica, has led to the identification and quantification of eleven terpenoids, -pinene (70%), -pinene (1.94%), 3-carene (0.2%), carveol (2.18%), epoxypinene (2.15%), limonene oxide (9%), myrtenol (5.31%), limonene (0.62%), citral (5.72%), -phellandrene (0.2%), and -myrcene (0.3%). The total amount of essential oil obtained was 22% v/w which is higher than any other species of the genus Pestacia.     

Determining the wax content of crude oils by using differential scanning calorimetry

By the use of differential scanning calorimetry (DSC), a new method to measure the wax content of crude oil has been developed. In this paper, the wax content of a crude oil is proposed and proved to be the Q (total thermal effect of wax precipitation in sample) ratio of the crude oil and its corresponding wax obtained by using standard acetone method, i.e. Q_oil/Q_wax. For the 14 studied crude oils with the wax content ranging from 1 to 27 wt.%, the wax contents determined by the presented method are in good agreement with those determined by standard acetone method, with an absolute average deviation of only 0.82 wt.%. This method has an advantage over reported DSC methods in which the exact dissolution or precipitation enthalpy of wax is a must. It is also found that the wax contents determined by either of the two methods show good linear relationship with the total thermal effect Q_oil, with the correlation coefficients over 0.96. According to the empirical correlations, the wax content of a crude oil can be easily determined by using the DSC total thermal effect Q_oil. In addition and more significantly, the new method can be applied to improve the accuracy in determining the amount of precipitated wax in a waxy crude oil at different temperatures.     

Ultra-fast essential oil characterization by capillary GC on a 50 microm ID column

A 5 m x 50 microm capillary column with 0.05 microm stationary phase film thickness, with a calculated efficiency of almost 20,000 plates per metre (under optimum conditions), was used for very fasthigh resolution GC analysis of lime essential oil. The total analysis time of this volatile essential oil was less than 90 s. Fast GC is shown to be appropriate for essential oil quality assurance analysis, and quantitative results of key components are comparable with those obtained by using conventional GC analysis. The fast GC analysis is approximately 33 times faster than the conventional GC method.     

原油溶胶-凝胶等温转变过程中的流变性研究

使用RS75流变仪，采用小振幅振荡剪切方法和稳态剪切方法对含蜡原油在溶胶 -凝胶等温转变过程中的流行了研究．结果表明，等温转变成的凝胶原油的结构在 很大程度上决定于预剪切速率，非牛顿含蜡原油在结构恢复过程中表现出不可逆的 触变特性．而凝胶原油在外力作用下向溶胶状态转变的过程中，要经历从线性粘弹 性变形，到非线性粘弹性变形，再到结构屈服的过程，且高剪切应力下的溶胶原油 结构与预剪切速率无关．     

The synthesis of a precursor of polybenzimidazole (PBI) and blends with polyamic acid (PAA)

The precursor of polybenzimidazole (PBI), poly(3,3′-diamino-4,4′-benzidine isophthalamide) (PDABI), was synthesized from poly(3,3′-dinitro-4,4′-benzidine isophthalamide) (PDNBI) by reduction. With increasing temperature, the NH₂ moiety which was protected by SnCl₅^?1 could cyclize and form PBI. Blends with polyamic acid (LaRC-TPI) were prepared. Clear blend films were prepared at up to 400°C. The IR spectra displayed shifts in the NH stretching band, thereby providing evidence for specific interactions related to the miscibility of their cured blends. © 1993 John Wiley & Sons, Inc.     

THERMAL PROPERTY, MISCIBILITY AND CRYSTALLIZATION BEHAVIOR OF POLY（3-HYDROXYBUTYRATE-co- 3-YDROXYHEXANOATE） AND POLY（BUTYLENE SUCCINATE-ADIPATE） （PHBHHX/PBSA） BLENDS

Blends of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and poly(butylene succinate-adipate) (PBSA), both biodegradable semicrystalline polyesters, were prepared with the ratio of PHBHHx/PBSA ranging from 80/20 to 20/80 by melt mixing method. Differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), dynamic mechanical thermal analysis (DMA), polarizing optical microscopy (POM) and wide angle X-ray diffractometer (WAXD) were used to study the miscibility and crystallization behavior of PHBHHx/PBSA blends. Experimental results indicate that PHBHHx is immiscible with PBSA as shown by the almost unchanged glass transition temperature and the biphasic melt.     

High temperature polymer blends: an overview of the literature

A review of work which has been performed on high temperature polymer blends is presented. The discussion is divided into miscible and immiscible blends. It is pointed out that one problem with miscible polymer blends is that of processing in the miscible state. In the case of immiscible blends, particularly ones containing liquid crystal polymers, the issue of adhesion of the two phases is discussed. Finally, the need for better theoretical models for predicting miscibility in polymer blends is highlighted.     

Quantitative determination of paraffin oil in blood by capillary gas chromatography

A capillary gas chromatographic method is described for the quantitative determination of liquid paraffin in blood. Paraffin is extracted from blood into n-heptane. After solvent evaporation and dissolution of the residue in 100–200 μl n-heptane one μl is injected into a gas chromatograph fitted with a fused silica capillary column (Permabond® OV-1-CB-0.1, 10 m × 0.32 mm i.d.) and flame ionization detector. Analysis is performed by using an oven program [50°C (3 min)?285°C (5 min), rise 10%min]. The sensitivity (1.5 ng hexadecane) and the reproducibility prove the applicability of the method for the determination of liquid paraffin in blood and for the study of the stability of the liquid paraffin hollow fiber membranes used in an extracorporeal liver support system.     

Thermal behaviour and slow molecular mobility in two isomers of biphenylmethanol

This research was aimed to investigate the role of clay on the combustion and kinetic behavior of crude oils in limestone matrix. For this purpose, simultaneous TG (thermogravimetry) and DTA (differential thermal analysis) experiments were performed at three different heating rates as 10–15 and 20°C min^–1, respectively. A uniform trend of decreasing activation energies was observed with the addition of clay. It was concluded that clays surface area affects the values of Arrhenius constant, while it is the catalytic properties of clay, which lower the activation energies of all the reactions, involved in the combustion process.