PET固相缩聚结晶评价的数学模型

聚对苯二甲酸乙二酯(PET)的固相缩聚(SSP)系指将固相聚合物切片在约200℃的温度下,保持足够的时间,以使切片达到所需要的特定粘度.这一过程是在一台管式反应器中连续进行的.与切片逆流通入氮气,以除去固相聚合过程中     

2004年中国新建聚合物和化纤工厂

公司 纤维(聚合物) 工程公司 江阴三房巷(江苏三房巷实业集团总公司) 开平聚醛(开平霍尼韦尔工业聚合物有限公司) 山东博莱特化纤有限责任公司 常州华源曾迪斯有限公司 短纤/长丝 固相缩聚,瓶级 固相缩聚,瓶级 固相缩聚,瓶级 固相缩聚,瓶级 固相缩聚,瓶级 固相缩聚,工业丝 固相缩聚,瓶级 固相缩聚,瓶级 固相缩聚,瓶级 固相缩聚,瓶级 固相缩聚,瓶级 固相缩聚,瓶级 固相缩聚,瓶级 固相缩聚,瓶级 固相缩聚,瓶级 固相缩聚,瓶级 固相缩聚,工业丝 聚合 聚合 聚合 瓶级切片 聚合 瓶级切片 聚合 聚合 聚合 瓶级切片 聚合 聚合 聚合 长丝 熔体/切片 …     

国标固相缩聚工厂设计规范的解析

对化纤工业工程建设制定的国家标准GB51115《固相缩聚工厂设计规范》进行了研究,从建设水平、标准体系、节能、节地、安全及工艺技术和社会效益方面进行了分析;得出规范实施有利于提高固相缩聚工厂的建设水平,实现聚酯(PET)产业链下游行业工程设计标准体系的全覆盖,避免了行业交叉、低水平的重复建设带来的浪费,有利于国家节能减排方针的贯彻执行。     

PET转鼓干燥系统的改进

探讨了涤纶切片的干燥技术;通过对转鼓干燥系统的真空度、干燥程序曲线和干燥切片批量的改进,得出比较合理的工艺,从而使PET切片含水少于30ppm,提高了PET熔体质量,使丝的可纺性能良好。     

固相缩聚生产中切片粘连的预防

分析了在聚酯切片固相缩聚中,切片粘连的原因,介绍了有效控制粘连现象发生的经验,包括合理的升温控制、氮气流量、反应温度等。     

提升我国高强聚酯纱产业链竞争能力的技术途径探讨(Ⅰ)——高粘度聚酯技术的进展

近年来,高粘度聚酯技术在两大热门市场——包装材料和产业用纤维的促进下不断进步,新型固相与液相缩聚工艺制备高粘度聚酯技术取得了长足进展。其中,新型固相缩聚、无SSP高粘度聚酯以及高粘度PET熔体直接成形或直纺等新技术都已投入工业化生产。与常规连续聚合、固相聚合等工艺相比,它们在投资/产能比、能耗、原料消耗、人力成本和生产弹性等方面具有明显的优势。     

固相缩聚结晶风机变频节能改造

介绍了变频器在固相缩聚瓶级切片生产中结晶风机调速节能改造中的应用，分析了风机凋速节电的原理。实践证明：利用变频器调速是风机节能改造的首选方案。     

阳离子染料易染改性聚酯的固相缩聚工艺与性能

为改善常压型阳离子染料易染聚酯(ECDP)纤维的力学性能,通过提高其切片特性黏度的方法,以熔融缩聚制得的ECDP切片为原料,通过固相缩聚法对其进行增黏得到增黏切片。借助乌氏黏度计、差示扫描量热仪、X射线衍射仪、荧光光谱仪和热失重分析仪等对增黏切片的性能进行测试与表征。结果表明:ECDP切片的固相增黏工艺最佳条件为温度190 ℃,时间9 h;随着反应温度的升高或反应时间的增加,切片的特性黏度增加,且特性黏度与时间的平方根成线性关系;在190 ℃、9 h条件下增黏的切片特性黏度为0.69 dL/g,高于该温度或时间时,切片发生热降解,表面开始变黄。     

PET固相缩聚反应的影响因素

ＰＥＴ的固相缩聚是将低分子量预聚体加热到熔点和玻璃化温度之间,切片内部缩聚反应持续进行,分子量不断提高,乙二醇、水等副产物借助真空或惰性气体带出反应器,固相缩聚中包括酯化反应、酯交换反应以及小分子的扩散过程。表观反应速率受预聚体颗粒形状大小、结晶度、惰性气体、反应温度、反应时间等因素的影响,其中反应温度、惰性气体中小分子副产物含量两个主要影响因素,应合理选择并控制这些参数,以利于生产由高质量的ＰＥ     

基于钛系催化剂制备的聚酯性能分析

为了改善传统钛系催化剂制得切片色泽泛黄、增黏效率低的问题,自制了一种新型钛系催化剂。利用该钛系催化剂成功制备了色泽良好、副产物含量低的聚酯切片,而且该切片还可进一步用于固相缩聚制得工业丝高黏切片。自制新型钛系催化剂在较低用量(2.5×10^-5)时可聚合得到黏度为0.65 dL/g左右的聚酯切片,通过乌氏黏度计、容量滴定法、DSC热分析等对其性能进行研究。结果表明：所制备的聚酯色相良好,其b值最低可达1.17,远低于现有钛系催化剂制备的聚酯切片(b值为5.55),聚酯的端羧基浓度为16 mol/t,低聚物质量分数在2.0%左右。同时,聚酯切片在230℃固相缩聚8 h后,其特性黏度可达1.10 dL/g,增黏效率高,为钛系催化剂在聚酯规模化应用提供有益参考。     

回收再利用PET瓶片的增值

消费后PET瓶子的回收再利用一般用于纺织品（或服装）、地毯、薄膜以及注塑制品。相对于其他级别的PET,瓶级PET质量较高,并具有较好的性能。为生产高性能的PET产品,恢复这种等级很重要。PET瓶片的等级可以通过固相聚合（SSP）进一步提高。     

高分子量聚对苯二甲酸乙二醇酯中低聚物的提取及其表征

为研究高分子量聚对苯二甲酸乙二醇酯（HMW-PET）中低聚物的成分和含量及其对HMW-PET结晶和热学性能的影响,通过萃取法和沉淀法对纤维级PET、液相增黏和固相增黏HMW-PET产品及过程样中的低聚物进行提取,并借助超高效聚合物色谱和差示扫描量热仪对低聚物进行表征。结果表明：沉淀法可快速分离不同工艺产品中的低聚物,得到的低聚物种类较齐全;而萃取法准确性较高,重复提取偏差控制在3% 以内;不同工艺制备的HMW-PET产品低聚物含量存在明显差异;萃取的低聚物在246.6、310.7 ℃附近出现吸热峰,其中环状三聚体含量最高;纤维级PET 及HMW-PET经提取后冷结晶温度均升高,但纤维级PET 熔融焓降低,而HMW-PET熔融焓升高。     

有机颜料微胶囊在涂料印花中的应用

将原位细乳液聚合制备得到的有机颜料微胶囊应用于棉织物的涂料印花,考察了色浆构成方式、微胶囊壁材和印花工艺等因素对印花效果的影响。结果发现,与传统颜料印花相比,微胶囊印花织物的耐干湿摩擦牢度、手感和K/S值均有不同程度的提高,表明颜料的微胶囊化处理可有效提高颜料颗粒与织物表面的结合牢度以及颜料在织物表面的分散均匀性。同时受高分子链段柔顺性和运动能力的影响,微胶囊壁材对印花效果也具有较为明显的影响,以丙烯酯丁酯共聚少量刚性单体为壁材的微胶囊印花效果最佳,此时较佳的焙烘温度为140℃,焙烘时间为5 min。     

Application of Electrohydrodynamic Technology for Folic Acid Encapsulation

Folates are a group of vitamins vital for the growth and development of the central nervous system. Most of these natural derivatives of folic acid are prone to oxidation and are very sensitive towards heat, temperature, oxygen, and light. Encapsulation of folic acid within inert matrices of a polymer can improve its stability and stop its degradation by light and oxygen. Electrohydrodynamic (EHD) technology is capable of generating fine droplets ranging from micrometers to nanometers in diameter from the breakup of a jet depending on the flow rate and applied electrical potential difference. The aims of this study were to generate nano-sized particles of folic acid encapsulated in sodium alginate (Na alginate) using EHD technology and to study the effect of voltage and flow rate on particle size as well as the structure of the prepared particles. It was established that 40 mg/ml (Na alginate) concentration can be used in single jet EHD technology. However, only 10 mg/ml concentration furnished stable jetting at any applied voltage and flow rate. So, this concentration was utilized and used to encapsulate higher dosages of folic acid. It was observed that the optimum flow rate for obtaining spherical particles of uniform diameter (4.2?±?1.2 μm) was 10 μl/min at a voltage of 12 kV. Upon drying, these particles acquired a diameter in the range of 50–200 nm and became less spherical in shape. As the folic acid concentration is increased from 1 to 10 mg/ml, the percentage yield of particles at a constant Na alginate concentration increased by over 10 % and the corresponding encapsulation efficiency doubled. FTIR spectroscopic studies revealed the presence of folic acid within Na alginate matrices and also no characteristic chemical interaction between them. It can be concluded from the above research findings that, at 10 mg/ml Na alginate concentration, 10 μl/min flow rate, and 12 kV voltage, a high amount of folic acid (5 mg/ml) can be encapsulated within Na alginate matrices, with high percentage yield (70 %) and loading capacity (96 %), generating non-spherical dried beads/particles of 90–150 nm in diameter.     

Application of laminated and metalized films to prolong the shelf life of dried barberries

Barberry is a nutritional and therapeutic crop mostly dried and consumed in bulk. However, the lack of proper packaging leads to the decline of many of its valuable properties. The aim of this study was to investigate the effect of different packaging films on barberries properties during storage. 150 g of freshly dried barberries were kept for 6 months at 25 °C within different packaging materials: (i) low-density polyethylene (LDPE); two laminated layers film including LDPE and polyethylene terephthalate (PET) with a total thickness of (ii) 45 μm (LDPE/PET-45) and (iii) 60 μm (LDPE/PET-60); (iv) oriented polypropylene (OPP); (v) three laminated layers film of OPP (3OPP); (vi) three laminated layers film including LDPE, metalized PET and PET (LDPE/mPET/PET); and (vii) four laminated layers film including LDPE, PET, aluminum foil and PET (LDPE/PET/Al/PET). After six months, the least change in moisture content, the lowest loss of DPPH scavenging capacity (97.9%), the minimum overall color difference, and the least increase in acidity (39.3%) were related to barberries packaged in the LDPE/PET-45 film. This is while the lowest loss of ascorbic acid (99.8%) and anthocyanin (62.8%) contents and the minimum microbial deterioration were related to the LDPE/PET-60 film. On the other hand, the LDPE/PET/Al/PET film entailed the lowest barberry weight loss (0.67%) and the minimum increase in firmness (40.7%), while the 3OPP film providing the best preservation of phenolic compounds. In conclusion, it seems two laminated layers films composed of LDPE and PET are appropriate for the preservation of dried barberries during storage.     

Contaminants and levels of occurrence in washed and shredded poly(ethylene terephthalate) from curbside collection. II: Validation of extraction procedures, particle size sampling and crystallinity

Part I of this study showed that washed and dried, shredded poly(ethylene terephthalate) (PET) (flake) obtained from curbside collection when Soxhlet extracted contained 26 semivolatile contaminants below the US FDA threshold of 215 ppb and six above this level. This paper reports the validation of the Soxhlet extraction technique by comparison with total dissolution with trifluoroacetic acid (TFA). The work was carried out for two of the three particle size ranges obtained by grinding the PET flake (300-425 and 425-700 μm) and for the unground flake. Further validation was undertaken by comparison of contaminant levels determined by total dissolution with TFA and sonication with dichloromethane (DCM) using flake ground to the 0-300 μm size range. The levels of contaminants increased with decreasing particle size range, but X-ray diffraction measurements of degrees of crystallinity were similar for each PET particle size range, thus showing that the differences in contaminant levels were not due to variable percentages of the amorphous material from the tops and bottoms of shredded bottles, relative to the amounts of crystalline PET from the mid-sections of the bottles. Hence, it was postulated that the variations in contaminant levels were due to selective grinding of the more highly contaminated surfaces, whilst the larger particles incorporated the less contaminated interior material. The grinding was also strongly selective with respect to the amorphous flake. Analysis of the segregated amorphous and crystalline flake phases indicated that many contaminants were similarly absorbed into both phases, whilst some were preferred by the amorphous PET and others were preferred by the crystalline PET.     

丙烯酸和胶原蛋白对PET的表面改性研究进展

聚对苯二甲酸乙二醇酯（PET）具有良好的物理化学性能,作为植入性生物材料具有较好的应用前景,但是其疏水性和生物惰性,制约着材料在医学上的应用,因此对材料进行改性以提高材料的生物相容性尤为重要。文章首先简述了表面改性尤其是PET表面改性的必要性;其次,论述了国内外用丙烯酸对PET进行改性的研究现状;接着论述了用胶原蛋白对医用高分子材料进行改性处理以提高材料生物相容性的研究现状;最后,指出了PET改性材料的应用前景。     

新一代应用于聚合物熔体过滤器的清洁技术

介绍了Longworth公司用于聚合物熔体过滤器的新一代DEECOM清洁技术以及检验方法。新技术可以降低运行成本和公用工程消耗,减少对环境的影响;在聚酯熔体过滤器的清洁中可以达到热解工艺和TEG化学清洁工艺的水平,并可用于聚酰胺、聚乙烯和聚乙烯醇等熔体过滤器的清洁。     

不同包装材料对真空冷冻干燥杨梅品质影响

研究3种包装材料铝箔袋、PET塑料瓶和玻璃瓶分别对25 ℃避光贮存90 d期间冻干杨梅品质的影响。通过比较不同存放时间的冻干杨梅水分含量、色泽、花色苷含量、质构、V_C含量和总酚含量变化,分析何种包装材料更适合包装冻干杨梅。结果表明:铝箔袋贮存的杨梅90 d后水分含量最低,为6.52%,色泽最红(a^*值24.05),硬度为20.08 N,V_C、总酚和花色苷保持的最好,分别为49.36 mg/100 g、25 μg/g和44.23 mg/100 g。其次是玻璃瓶,而PET塑料瓶效果最差。综合考虑冷冻杨梅干品质和成本,铝箔袋包装冻干杨梅优于塑料瓶和玻璃瓶包装。     

阻燃涤纶的性能及应用

由双官能团磷系阻燃剂与普通聚酯单体共聚而成的聚合物制得的阻燃涤纶 ,限氧指数达 34% ,以其永久阻燃性的独特优点 ,用于开发永久阻燃性织物 ,如产业用纺织品、装饰材料和防护服等 ,有着良好的应用前景 ,将是我国纺织品市场上的一个新热点。