利用废聚酯合成对苯二甲酸二(2-乙基)己酯

研究了以废聚酯(PET)为原料,钛酸四正丁酯(TBT)为催化剂,在非质子极性溶剂N-甲基-2-吡咯烷酮(NMP)中制备对苯二甲酸二(2-乙基)己酯(DOTP).探索了反应时间、物料摩尔比、溶剂种类和用量对醇解产物收率的影响.结果表明,反应初始阶段为非均相阶段,固-液间传质系数是影响反应速率的主要因素,加入NMP可以加速PET的溶解,促使醇解反应快速进入均相阶段.在n(2-EH)/n (PET)=4,m(TBT)/m (PET)=0.5%,V(2-EH)/V (NMP)=4的条件下,反应2 h,产物DOTP的收率为78.10%.     

玉米乙二醇合成PET的研究

以玉米为原材料生产的乙二醇合成PET并进行固相缩聚,对其生产过程及其结果进行分析和讨论。     

Use of organic compounds of boron to prepare fire-proofed polycaproamide fibres

Conclusions The basic possibility of preparing flame-proofed PCA fibres by treating them with boron-containing flame-proofers has been demonstrated.The effect of the chemical composition of polyesters of boric acid on the flame-proofed properties of PCA fibres has been examined.Translated from Khimicheskie Volokna No. 1, p. 26, January-February, 1984.     

丁烷四酸稀土和锌盐的合成及其在尼龙66和聚酯中应用研究

将合成的丁烷四酸镧(BTL)、丁烷四酸铈(BTC)和丁烷四酸锌(BTZ)与尼龙66和聚酯共混,采用热重法和红外光谱等手段表征有机酸盐以及改性尼龙和聚酯的结构。结果表明,稀土盐的热稳定性优于锌盐;丁烷四酸稀土和锌离子与酰胺基团之间的强络合作用能够加快尼龙66的热降解;丁烷四酸稀土没有改变聚酯的热稳定性,但在一定程度上缓解了聚酯的高温热降解,促进了高温碳化。     

Synthesis of polyethylene terephthalate in the presence of 4-carboxybenzaldehyde

Conclusions Contamination of terephthalic acid with 4CBA causes a decrease in the whiteness of the finished polyethylene terephthalate and the appearance of branched structures due to reactions of the aldehyde group.To obtain high-quality polyethylene terephthalate with good color characteristics, it is very advisable to use stabilizers which reduce the aldehyde group in 4CBA, phosphites for example.Translated from Khimicheskie Volokna, No. 4, pp. 9–11, July–August, 1983.     

有机硼改性酚醛树脂的合成

以硼酸,苯酚,甲醛为原料,碳酸钠作催化剂合成具有耐高温性能的硼酚醛树脂。通过IR,对这种热固性有机硼改性酚醛树脂的结构进行了表征。树脂的热失重分析结果表明此树脂耐热性优于普通酚醛树脂,所得产物在900℃残留物为76．38％。确定了最佳反应条件为:苯酚:甲醛:硼酸=1:2:0．3(摩尔比),缩合反应温度70-75℃,硼酯化反应温度100-104℃,在控制反血时间下脱水一次。     

Synthesis of polyethylene terephthalate in the presence of sodium heptagermanate

Conclusions A limited effect of NaHG on the dehydration of EG by an intermolecular mechanism has been shown.The suggestion has been made that the basic amount of water on heating solutions of NaHG in EG is formed by a radical mechanism, the initiator for which is peroxides formed on reaction of the NaHG with EG.The presence of an ester in the system suppresses the water formation process by the suggested radical mechanism.The results obtained permit one to recommend NaHG as a polycondensation catalyst in the preparation of PET having special properties (increased whiteness, low ash, transparency), since it does not cause additional side reactions in the synthesis.Translated from Khimicheskie Volokna, No. 3, pp. 19–21, May–June, 1986.     

Characteristics of hydroxybenzoic acid-ethylene terephthalate copolymers and their blends with polystyrene,polycarbonate, and polyethylene terephthalate

We present a basic study of the thermal, dielectric, Theological, and mechanical properties of hydroxybenzoic acid-ethylene terephthalate copolymers (PHB-PET). It is argued that they have two-phase structures, one rich in ethylene terephthalate (PET) and one rich in hydroxybenzoic acid (PHB). Polystyrene (PS) is immiscible in 60% PHB-PET (60-PHB-PET) blends. Polycarbonate (PC) is partially miscible with the high PET phase of 60-PHB-PET. PET seems completely miscible with this high PET phase. Shear viscosity measurements on blends indicate that 60-PHB-PET gives rise to large reductions of viscosity. Extrudates and melt-spun fibers have been prepared. The phase morphologies of low PHB-PET blends as determined by scanning electron microscopy indicate ellipsoids or long fibrils of the, 60-PHB-PET in PS or PC matrices. High extrusion rates and melt spinning produce fibrillar structures. The mechanical properties of films, extrudates, and melt-spun fibers were studied. Blends with 10% 60-PHB-PET exhibited significant increases in Young's modulus and tensile strength.     

Kinetics of drying polybutylene terephthalate and polyethylene terephthalate granulate

In studying the dynamics of drying of PBT and PET granulate, the parameters of the process that ensure sufficient process stability of their melts were determined. It was found that the rate of self-ordering of structural elements in the polymer substrate in drying is higher in PBT than in PET due to the greater flexibility of the macromolecules. __________ Translated from Khimicheskie Volokna, No. 1, pp. 7–10, January–February, 2006.     

Synthesis of (polyethylene terephthalate/poly?-caprolactone) copolyesters

Polyethylene terephthalate (PET) was alcoholised with ethylene glycol to synthesize hydroxytelechelic oligomers of PET. On the other hand, commercial hydroxytelechelic poly?-caprolactone was modified in order to synthesize carboxytelechelic poly?-caprolactone. The chemical structure of the products was investigated by ¹H NMR. Multiblock copolyesters were then synthesized by polyesterification of hydroxytelechelic PET and carboxytelechelic poly?-caprolactone oligomers, using several catalysts and different reaction conditions, which have been linked with the average molecular weight of the obtained block copolyesters. It appeared that residual distannoxane species coming from glycolysis step are best catalyst for polyesterification reaction. The chemical structure of the synthesized copolyesters was investigated by size exclusion chromatography and ¹H NMR. The thermal and thermomechanical behavior of the synthesized copolyesters was investigated by differential scanning calorimetry and by dynamic mechanical analyses. The ester-ester interchange reaction between the two types of oligopolyesters has been enlightened and estimated taking in account the different reaction parameters. This side reaction led to the miscibility of the two phases of the oligomers, that can be explained by a random structure of the copolyester, and prevented to obtain multiblock copolymer.     

亚锡类催化剂催化合成对苯二甲酸二异辛酯的研究

以3种亚锡类催化剂氧化亚锡、氯化亚锡、辛酸亚锡以及它们之间复配后作为催化剂,对对苯二甲酸二异辛酯酯化反应的催化活性进行了研究,实验结果表明,以氧化亚锡和辛酸亚锡复配后的催化活性最高,氧化亚锡和辛酸亚锡作为催化剂的酯化反应最佳合成工艺条件为:催化剂的加量为0.25%(重量比),反应温度为220℃,醇酸摩尔比为3.0?1,在最佳工艺条件下,产品的终点酸值为0.62 mgKOH/g,对苯二甲酸的转化率达99.75%。     

Action of alkali on polybutylene terephthalate and polyethylene terephthalate polyesters

The two polyesters (polybutylene terephthalate and polyethylene terephthalate) were treated with aqueous as well as alcoholic solutions of sodium hydroxide at varying temperatures for different durations of time. The results were evaluated in terms of the loss in weight of the samples. The fabric samples of polyethylene terephthalate showed a greater degree of weight loss as compared to those of polybutylene terephthalate. The mechanism for the differences in the action of alkali on these two polyesters is explained. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1097–1102, 2000     

Cold drawing of polyethylene terephthalate/polyethylene films

Films made from a 77/23 weight percent polyethylene terephthalate/polyethylene blend were stretched using an Instron apparatus. The structures of the samples were examined by methods which included ion beam etching and electron microscopy. The drawn samples exhibited a metallically lustrous and highly reflective surface up to a draw temperature, T_R, of 70°C and a draw ratio of about 5. Under certain conditions the change in structure caused by the stretching resulted in the formation of a highly uniform fibril-void structure. The voids are up to 3 μm in width and 160 μm in length and are formed primarily as a result of aggregation and then separation of the microfibrils of the individual polymer components.     

Periodic fabrication of polyethylene terephthalate

Translated from Khimicheskie Volokna, No. 4, pp. 21–23, July–August, 1994.     

Heterogeneous crystallisation of polyethylene terephthalate

An examination of the effect of various inorganic and organic additives on the crystallisation behaviour of polyethylene terephthalate has been made. Various methods of mixing the polymer and additives were also investigated and one involving screw extrustion was finally adopted. Crystallisation studies were carried out using Differential Scanning Calorimetry under dynamic and isothermal modes covering both normal and cold-crystallisation conditions. Using screw extrusion mixed material it was found that almost all additives produced some nucleating effect as indicated by an increase in the rate of crystallisation. In particular, sodium benzoate and sodium stearate (1 per cent w/w) had the greatest effect, decreasing the initial cold-crystallisation temperature and increasing the temperature of equivalent half-times of isothermal crystallisation, both by about 20°C.     

Thermal stability of polyethylene terephthalate

The kinetics of thermal and thermal-oxidative degradation of polyethylene terephthalate (PET) have been investigated as a function of melt temperature, melt residence time, melt environment, and drying environment. Rates of thermal and thermal-oxidative degradation were measured in terms of: weight loss of volatile degradation products, decreasing inherent viscosity, and increasing carboxyl end group concentration. Thermal-oxidative degradation was also investigated by Differential Scanning Calorimetry. Calorimetric results show that thermal-oxidative degradation of PET is an exothermic reaction, with an apparent activation energy of 117 kJ/mol. Melt temperature, melt residence time, melt environment, and drying environment have all been found to affect the degradation of PET. Analysis of inherent-viscosity kinetic data has been carried out, utilizing existing theories based on a random chain scission mechanism. Activation energies of 117 and 159 kJ/mol have been calculated for air-dried and vacuum dried samples respectively.