表面接枝含氟苯乙烯共聚物的聚酯薄膜制备与表征

利用表面引发原子转移自由基聚合(SI-ATRP)在聚对苯二甲酸乙二醇酯(PET)薄膜表面接枝苯乙烯和4-氟苯乙烯的共聚物.研究不同反应时间和不同配比下接枝共聚物对聚酯薄膜表面组成、结构和性能的影响.通过傅利叶变换红外光谱仪(ATR/FTIR),X-射线光电子能谱仪(XPS),凝胶渗透色谱(GPC)和扫描电子显微镜(SEM)对接枝改性前后PET薄膜的表面组成,结构和形貌进行分析;利用接触角测试和表面能计算对比研究接枝改性前后PET薄膜的表面性能.结果表明反应时间和单体百分含量对接枝百分率及接触角有一定的影响,随着反应时间的增长,聚酯薄膜表面接枝百分率增大,接触角增加,表面自由能下降.     

Nonlinear current-voltage characteristics of conductive polyethylene composites with carbon black filled pet microfibrils

Current-voltage electrical behavior of in situ microfibrillar carbon black (CB)/poly(ethylene terephthalate) (PET)/polyethylene (PE) (m-CB/PET/PE) composites with various CB concentrations at ambient temperatures was studied under a direct-current electric field. The current-voltage (I-V) curves exhibited nonlinearity beyond a critical value of voltage. The dynamic random resistor network (DRRN) model was adopted to semi-qualitatively explain the nonlinear conduction behavior of m-CB/PET/PE composites. Macroscopic nonlinearity originated from the interfacial interactions between CB/PET micro fibrils and additional conduction channels. Combined with the special conductive networks, an illustration was proposed to interpret the nonlinear I-V characteristics by a field emission or tunneling mechanism between CB particles in the CB/PET microfibers intersections.     

Poly(ethylene terephthalate) copolymers containing nitroterephthalic units. III. Methanolytic degradation

The methanolytic degradation of poly(ethylene terephthalate) (PET) copolymers containing nitroterephthalic units was investigated. Random poly(ethylene terephthalate‐co‐nitroterephthalate) copolyesters (PETNT) containing 15 and 30 mol % nitrated units were prepared from ethylene glycol and a mixture of dimethyl terephthalate and dimethyl nitroterephthalate. A detailed study of the influence of the nitro group on the methanolytic degradation rate of the nitrated bis(2‐hydroxyethyl) nitroterephthalate (BHENT) model compound in comparison with the nonnitrated bis(2‐hydroxyethyl) terephthalate (BHET) model compound was carried out. The kinetics of the methanolysis of BHENT and BHET were evaluated with high‐performance liquid chromatography and ¹H NMR spectroscopy. BHENT appeared to be much more reactive than BHET. The methanolytic degradation of PET and PETNT copolyesters at 80 °C was followed by changes in the weight and viscosity, gel permeation chromatography, differential scanning calorimetry, scanning electron microscopy, and ¹H and ¹³C NMR spectroscopy. The copolyesters degraded faster than PET, and the degradation increased with the content of nitrated units and occurred preferentially by cleavage of the ester groups placed at the meta position of the nitro group in the nitrated units. For both PET and PETNT copolyesters, an increase in crystallinity accompanied methanolysis. A surface degradation mechanism entailing solubilization of the fragmented polymer and consequent loss of mass was found to operate in the methanolysis of the copolyesters. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2276–2285, 2002     

PET导电纤维的制取及研究

以过氧化二苯甲酰为引发剂,使丙烯睛在涤沦(PET)纤维上接枝共聚。接枝纤维在含铜化合物,含硫还原剂溶液中反应,制备PET导电纤维。讨论了影响接枝共聚的各种因素,选择出最佳聚合条件。对该纤维的导电成份和结构以及性能进行了研究。     

涤纶织物热定型后动态力学行为

利用Rhcovibron DDV-II-EA型动态粘弹谱仪测试了PET平纹布在不同温度热定型后的布样及其经、纬纱的动态力学性质。发现布及其纱的动态力学-温度谱与原纤维的截然不同。在[Ε]-T 曲线上出现[Ε]峰,[Ε]_max值随织物热定型温度的增高呈指数下降,峰位向高温移动。同时在Ε’’-T曲线上出现双损耗模量峰,相应的松弛转变活化能相差半个数量级。初步分析认为,与织布过程及随后的织物热定型有关。     

Recycling of polyethylene terephthalate (PET Or PETE) plastics – An alternative to obtain value added products: A review

Waste management is become one of the world's most pressing issues. Plastic is one of the most widely utilised materials in the modern world. Plastic manufacturing and usage have risen globally in recent decades due to its low weight and outstanding mechanical properties. Plastic has a wide range of applications due to such good properties include lightweight, high strength, and extended durability. Because of plastics are non- or low-biodegradable, a vast quantity of plastic waste is generated every day, making waste disposal the most pressing matter globally. Furthermore, improper waste disposal pollutes the environment. An ecologically friendly approach is necessary to locket these issues. One of the solutions is to recycle this sort of garbage. There are many plastic recycling technologies available, however practically all of them have certain restrictions. Chemical recycling of plastic, on the other hand, has been shown to be more efficient than other recycling methods. This article provides a quick overview of chemical recycling of PET post-consumer waste and the synthesis of potentially value-added products such as dye or dyestuffs, bolaform surfactant, bio-degradable polyesters, drug carrier, Metal-organic framework (MOF), bio-degradable polymeric scaffolds, polyurethane foam and coating materials etc.     

Optimisation of mould surface temperature and bottle residence time in mould for the carbonated soft drink PET containers

Polyethylene terephthalate (PET) bottles, which are usually produced by injection stretch blow moulding (ISBM) are widely used for carbonated soft drinks (CSD) storage and transportation. Stretch rod movement, blow pressure, preform temperature profile, mould surface temperature and material properties are among the most important factors affecting the final product's quality in terms of the thickness distribution, burst pressure and top-load resistance of the bottles. However, the residence time of the blown bottle inside the mould is also an important factor affecting its final properties. Especially in PET bottle production for hot fillings, the residence time is a very important factor because the longer the residence time the better the crystalline structure of the PET. In this production, the lid section is desired to have a fully crystalline form so that it can withstand hot fluids. In this study, the aim was to optimise the mould surface temperature and the blown bottle's residence time inside the mould for 1 L soft drink PET bottle production based on the final properties using the ECHIP 7 design of experiment (DOE) program. The method employed through this program was a quadratic one. Optimum process parameters were determined by the response surface method (RSM) and the process settings ensuring maximum top-load, burst pressure, Tg and degree of crystallinity were regarded to be optimum. It was found that the optimum mould surface temperature and blown bottle residence time inside the mould were 10 °C and 20 s, respectively.     

聚对苯二甲酸乙二酯/蒙脱土纳米复合材料的制备和性能

讨论了聚对苯二甲酸乙二醇酯（ＰＥＴ）／层状硅酸盐（蒙脱土）纳米复合材料的制备技术和新材料的结构与性能特征．天然蒙脱土矿物经有机离子修饰剂处理后,参与ＰＥＴ的缩聚反应．ＴＥＭ测定证实蒙脱土在ＰＥＴ中的层厚分布为３０～５０ｎｍ．蒙脱土不影响ＰＥＴ的分子量及其分布．利用ＤＳＣ、ＷＡＸＤ、ＳＡＬＳ和偏光显微镜测定了ＰＥＴ／蒙脱土的结晶速率和结晶形态,说明ＰＥＴ／蒙脱土有着很快的结晶速率,不能生成球晶结构,一般只能生成结构不完整的微晶体．ＰＥＴ／蒙脱土在工程塑料和工业纤维领域有潜在的应用前景     

成核剂和促进剂对聚对苯二甲酸乙二酯结晶的影响

研究了一种成核剂和结晶促进剂及其混合物对聚对苯二甲酸乙二酯（ＰＥＴ）结晶过程和熔融行为的影响．结果表明,成核剂的引入降低了ＰＥＴ的结晶成核界面自由能,起到促进ＰＥＴ结晶成核的作用,从而加快了ＰＥＴ的结晶速度．而结晶促进剂对ＰＥＴ的结晶速度影响很小,不能促进ＰＥＴ的成核结晶,但能使ＰＥＴ结晶更完善,使ＰＥＴ的结晶度提高．当两者并用时,ＰＥＴ由熔体降温的结晶行为主要由成核剂控制,而成核促进剂的作用不明显．