酶对DTP及PET纤维的降解性能探讨

采用对苯二甲酸二乙酯作为PET的模拟物，选用4种脂肪酶对DTP和PET纤维的降解性能进行了研究。实验采用碱滴定、紫外分光光度计以及高效液相色谱法进行测试。对DTP降解液的pH值变化以及酶对DTP的降解率随时间的变化情况进行了分析。虽然酶对PET纤维的降解率很低，但通过SEN(电子扫描显微镜)和HPLC观察显示，纤堆表面仍然有被刻蚀的痕迹存在。     

超临界流体技术在PET解聚中的应用

研究了ＰＥＴ在超临界甲醇中的解聚行为及温度、压力和反应时间对ＰＥＴ解聚率的影响,发现ＰＥＴ在超临界甲醇中可迅速地完全解聚。红外光谱检测解聚产物是纯度很高的对苯二甲酸二甲酯（ＤＭＴ）单体和乙二醇。     

KINETICS AND MECHANISM RELATING ALKALINE HYDROLYSIS OF POLYESTER BLEND FIBER

Cation Dyeable Polyester(CDP)was made by copolymerizing dimethyl terephthalate(DMT),S-sodium sulfonate dimethyl isophthalate(SIPM) with a weight fraction of 4.5% and ethyleneglycol (EG).Blend of PET and CDP was spun into hollow fiber.The fiber was then treated withaqueous NaOH.In this paper,kinetics and mechanism of alkaline hydrolysis of PET,CDP andtheir blend PET/CDP fiber were studied by means of specific area measurement,scantling elec-tron microscopy and other chemical analyses.It was showed that the rate of alkaline hydrolysis isCDP>PET/CDP>PET.Because of blending effect,the alkaline hydrolysis of PET/CDP is dif-ferent from that of PET.CDP phase in the PET/CDP fiber is predominantly hydrolyzed,andhence some pieces of fiber(micro-fiber) fall off the fiber because of etching.     

紫外辐照在PET膜表面接枝氨基酸的研究

生物材料的表面性能是影响材料血液相容性的重要原因,生物材料的表面改性对提高其血上容性有重要意义,目前国内外公认的材料表面内皮细胞化是提高生物材料血液相容性最为理想的途径。     

PET/PEN共混物的热分解行为及其动力学

研究了惰性气氛下聚对苯二甲酸乙二酯(PET)/聚对萘二甲酸乙二酯(PEN)共混物的非等温热分解行为及其动力学.研究发现,不同PET/PEN共混物的热降解为一个主要的热分解过程,热分解反应为一级反应.随着共混物中PEN质量分数的增加,共混物的起始分解温度逐渐升高,共混物的热稳定性逐渐提高,而且共混物的热分解反应活化能也逐渐增加,这是由于PEN分子链中萘环的热分解温度比PET中苯环高,因此分子链的热稳定性比PET要高.共混物中萘环的化学组成含量越高,则热稳定性愈高.     

纤维增强PET复合材料等温结晶行为的研究

用差示扫描量热法研究了玻璃纤维、碳纤维、Kevlar 浆粕等增强纤维对PET等温结晶动力学参数的影响,发现增强纤维的引入能促进PET的结晶,其效果与纤维种类有关,以碳纤维最好,Kevlar浆粕次之;玻璃纤维最差.同时还比较了等离子处理增强纤维及成核剂对PET结晶行为的影响.通过对体系的结晶形态研究发现,增强纤维的引入没有改变PET的结晶形态,但纤维表面的晶核密度比基体大而形成一层柱状的微晶区.     

Combustion forming hollow nanospheres as a ceramic fortress for flame-retardant fiber

Simple, effective and safe flame retardants are required to improve flame retardant properties of polymer fibers.However, traditional additive flame retardants, such as halogen-flame retardants and intumescent flame retardants, are likely to cause phase separation of functional phases due to their poor dispersibility and compatibility, or are difficult to be suitable for the high temperature processing conditions of melt-spun fibers. Here, in an effort to develop a practical flame retardant system in which zinc diphosphinate(DEPZn) and D-glucose(DG)were selectively incorporated into polyethylene terephthalate(PET) fiber was developed. As a result, the dense nano-scale zinc phosphate microspheres were formed on the surface and inside the residual carbon during combustion. Thus, PET fibers were endowed with excellent flame retardancy through a thermal barrier and enhancement of physical strength for the carbon layer. Moreover, a synergistic flame-retardant effect was found between DEPZn and DG. DG reduced the size of the zinc phosphate nanosphere from 200 nm to 50 nm, making the carbon layer denser and smoother. As a result, the peak heat release of the resultant PET composite fiber decreased to 410 k W/m~2 compared 1276 k W/m~2 for neat PET fiber. Moreover, the total smoke release also dropped from 71 MJ/kg of neat PET fiber to 64 MJ/kg for PET composite fibers. These results provide a promising strategy for the production of industrialized PET flame retardant fibers.     

PBs/PET共混体系的制备与表征

以丁二酸、丁二醇为原料,通过直接缩聚反应合成了高分子量聚丁二酸丁二醇酯。并将聚丁二酸丁二醇酯 (PBS)同聚对苯二甲酸乙二醇酯 (PET)在不同温度下熔融共混。测定了不同组分共混物的熔点和水降解性。聚合物熔融峰随着共混时间的增加渐渐的下移。这说明PBS和PET热降解和酯交换反应随着共混温度的增加而同时发生。共混物的降解性与芳香组分的含量和链段长度都有关。     

PET—PTT共聚酯的热降解行为

采用热失重分析(TGA)和裂解气相质谱(Py-GC/MS)研究不同组成的PET(聚对苯二甲酸乙二醇酯)-PTT(聚对苯二甲酸丙二醇酯)共聚酯的热降解行为,并与PET和PTT均聚物作了比较.TGA结果表明,PET-PTT共聚酯的热稳定性介于均聚物PTT与PET之间,并随PET组分的增加而提高.利用Py-GC/MS得到PET-PTT共聚酯及均聚物的裂解产物的结构及分布,探讨PTT降解机理,并推测PET-PTT共聚酯的可能降解过程.发现PET-PTT共聚酯分解过程中产生了不同于PET和PTT裂解产物的组分,但不同组分的含量很小,这可能是由共聚酯中PTT(PET)序列长度较短所致.PET-PTT共聚酯在裂解过程中比PET和PTT均聚物产生了更多的挥发性产物.当PTT(PET)在共聚酯中的摩尔分数增大时由该链段降解产生的产物质量分数相应提高.     

Dynamics Model and Simulation of Polyethylene Terephthalate （PET） Hollow Fiber

On the basis of melt-spinning, the dynamics model of polyethylene terephthalate (PET) hollow fiber is established.The effects of spinning conditions on hollow ratio are discussed and verified. Because of the different quenching conditions, there exist differences of the hollow ratio and the vitrification distances between different cycles. The important role of the quenching conditions on the melt-spinning of PET hollow fiber is also mentioned.     

DEFORMATION AND FRACTURE OF FIBERS Part 4:Fracture Behaviour of PET and PAN Fibers in Tension

The dynamic observation of the fracture processes of PET(polyethylene terephthalate)andPAN(polyacrylonitrile)fibers in tension was carried out under a scanning electron microscope.Thestepwisc micrographs taken revealed the features of crack initiation and crack growth and of thefailure of the fibers.The fracture behaviour of PET fibers in tension is characterized by theoccurence of shear bands,which initiate a crack whose development leads to the final failure of afiber.For tensile PAN fibers,a high concentration of cracks are initiate in the skin of a fiber,andthen a few or one of them develop themselves by way of pulse and lead to the final failure of the fi-ber.     

蒙脱土改性PET纤维性能

采用熔融插层法制备聚对苯二甲酸乙二酯（PET）/蒙脱土（MMT）纳米复合材料,对其纤维的结晶性能、力学性能及染色性能进行详细研究.结果表明,与纯PET纤维相比,蒙脱土改性PET纤维具有较高的模量和较低的收缩率,改性纤维的上染率亦有明显提高.含磺酸基团改性的聚对苯二甲酸乙二酯（CDP）/MMT纤维的上染率和上染速率大于PET/MMT纤维,表明蒙脱土和聚合物中的离子基团对促进PET纤维的染色性能有协同作用.     

Synthesis and Application of Easy Hydrolysis Degradable Polyester

An easy hydrolysis degradable polyester (EHDP) is synthesized; the fiber produced from which can be hydrolyzed by dilute basic solution easily. The properties of these kind polyesters are measured. The results show that this kind polymer is suitable to be spun into filament The EHDP can be spun into staple fiber and manufactured into non-woven fabric. This fabric is used as disposable clothes. In composite spinning, the PET (polyethylen glycol terephthalate) or PA (poly amide) is used as continuous phase, and EHDP used as dispersed phase. Then the fabric of this kind fiber is treated by basic solution; the ultra-fine fiber fabric is obtained. The fineness of the fiber is about 0.045 dtex. In blend spinning, EHDP is mixed with polypropylene (PP) to produce hollow fiber with micro-holes hi radical direction. This fiber is a usable material in filter especially in medical use.     

低温等离子体诱导下导电高分子复合膜的制备

利用等离子体技术对PET薄膜进行表面处理,并诱导引发AAc在其表面接枝聚合,制备PAAc-g-PET复合膜,用化学氧化方法使PPy接枝聚合在PAAc-g-PET表面,制备出PPy-g-PAAc-g-PET复合膜.利用ATR-FTIR和SEM对制备的复合膜分别进行结构和表面形貌分析.导电性测试结果表明,PPy-g-PAAc-g-PET复合膜的导电性也明显提高.同时考察了温度、时间、浓度等对PPy-g-PAAc-g-PET复合膜接枝率的影响,得到PET薄膜接枝PPy的最佳条件为温度60 ℃,反应时间6 h.研究结果表明,PPy能很好地接枝到PAAc-g-PET复合膜的表面.     

化学镀法制备电磁屏蔽聚酯织物的研究

为开发具有电磁屏蔽作用的织物,采用化学镀法制备了具有电磁屏蔽性能的聚酯类化纤织物,并研究了化学处理方法——碱减量处理对涤纶织物表面化学镀层的性能及化学镀后织物的电磁屏蔽性能的影响。研究表明,在20g/LNaOH溶液中处理既可使纤维表面形成微观凹坑,增大比表面积,又可改非极性的疏水表面为亲水表面,提高表面活性,提高敏化和活化时金属离子和金属在纤维表面的吸附性,在化学镀过程中使基体与金属形成平整的结合。碱减量处理2～3h有利于提高镀层与织物结合牢度,并使镀层光亮均匀,电磁屏蔽性能更加优异。     

无声放电对聚酯织物表面的等离子体接枝改性

利用无声放电方法对聚酯（ＰＥＴ）纤维表面进行接枝改性,为改善聚酯织物的染色性能提供了一条新途径,傅里叶红外光谱（ＦＴＩＲ）和Ｘ射线光电子能谱（ＸＰＳ）表明,ＰＥＴ纤维经无声放电引发气相接枝丙烯酸改性后,表面的羰基、羟基和羧基等极性基团增加,氧碳摩尔分数比增大。扫描电镜（ＳＥＭ）观察发现纤维表面粗糙度随放电时间增加而增大,改性后的涤纶对碱性染料的上染率有所提高。     

Influence of Thermal Treatment on the Structure and Thermal Properties of Kaolin Modified Polyester Fibers

Modified polyester fibers were obtained using 2% and 6% of kaolin blends through melt spinning.The influences of two thermal treatments maintaining the original tension(180 ℃×2 min and 200 ℃×1 min)on the structure and properties of fiber were compared.The changes of grain size and crystallinity of fiber were investigated by X-ray diffraction(XRD).The changes of thermal properties of fibers were analyzed using dynamic mechanical analyzer(DMA).The results show that the crystalline structure of kaolin modified polyester fiber doesn't change with the thermal treatment.With the kaolin content increasing,the grain size of fiber changed.The higher the thermal treatment temperature is,the higher the crystallinity of fiber is.There are two glass-transition temperatures for kaolin modified:the lower one is the glass-transition temperature of polyester fiber matrix,and the higher one is derived from the heterogeneous blend of polyester matrix and nano kaolin.The higher the kaolin content is,the higher the glass-transition temperature is.Thermal treatment could increase the compatibility of polyester matrix and nano kaolin.There was only one glass-transition temperature for the thermal treatment fiber,and the heat resistance of fiber was improved.Thermogravimetric analysis-differential scanning calorimetry(TGA-DSC)results of kaolin modified polyethylene terephthalate(PET)matrix indicate that the decomposition temperature of PET fibers,kaolin modified PET fibers,and thermal treated fibers were little different within 40%-60% of weight loss rate range.     

对苯二甲酸及聚酯膜生物降解

聚酯废弃物形成的白色垃圾对环境的污染日益严重,采用生物方法降解聚酯是目前国际上研究的热点．对苯二甲酸是合成聚酯的主要原料,其本身也具有一定的毒性．作者采用从活性污泥中提取的菌株和粗酶液,对对苯二甲酸和聚酯薄膜进行生物降解探讨．实验结果和动力学分析表明,提取的菌株和粗酶液对对本二甲酸有很好的降解作用,对PET薄膜也有明显的刻蚀痕迹．     

铁氧体构成磁控管的磁场分析及它对PET表面改性的影响

在铁氧体磁场存在的情况下,通过研究涤纶膜（PET）表面的碳氟等离子体的改性效果受磁场的影响,讨论了带电粒子的行为及磁场对改性的影响．结果发现：磁场的存在使得PET表面的聚合区域向刻蚀区域位移,且主要依赖于磁场的强度．     

成核剂Na_2CO_3对PET结晶行为的影响

本文对Na_2CO_3在PET中的成核作用及机理、对结晶体结构变化、结晶动力学进行了讨论,比较了不同条件下结晶的PET晶体结构的差异。Na_2CO_3使PET结晶完善性,结晶度,晶体有序度增大,结晶速度加快,晶核尺寸变小,其成核作用是以化学反应机理进行的,成核中心是COO~-Na~+。