Non-isothermal Crystallization Kinetics of Modified Poly(ethylene terephthalate) with Ultraviolet Protection

The non-isothermal crystallization kinetics of modified poly(ethylene terephthalate) (PET) with the function of ultraviolet (UV) protection was studied by means of differential scanning calorimetry. The kinetics of the modified polymer wider non-isothermal crystallization was analyzed by Ozawa equation. The crystallization behavior of the modified polymer obeyed Ozawa theory. The additives in the polymer whose function was UV-resistant acted as crystal nucleus in the processing of crystallization, which resulted in the increase of Avrami index and the crystallization rate of the cooling system.     

Silk Fibroin Film Blended with Poly（ ethylene glycol-glycerin）

To improve the toughness of silk fibroin（ SF） films,poly（ ethylene glycol-glycerin）（ PEGG） was synthesized with ethylene glycol and epichlorohydrin. The SF / PEGG blend films were prepared by casting aqueous solution and their structures were characterized. The PEGG was in liquid state at room temperature so it will not be a single phrase at blend film. It crosslinked with SF and made it insolubility in water. The results of X-ray diffraction（ XRD） indicated that the crystallinity of the SF in the blend films decreased with the content of PEGG increasing. The tensile strength and elongation at break of blend films were measured using an instron tensile tester. The results showed that the tensile strength and elongation at break of blend films were high enough for application.After the blend films were stored at room temperature for 100 d,the crystallinity, the tensile strength and elongation at wet state increased. The blend films are superior to SF films in providing excellent flexibility and mechanical properties in both dry and wet states. Based on the fact that SF has good biocompatibility,the SF /PEGG blend film will offer new options in many different biomedical applications.     

Enzyme-Mediated Hydrolysis of Poly（ethylene glycol）-Supported Carbonates

Enzymatic kinetic resolution of racemic alcohols or esters is known as a useful method for the preparation of optically active secondary alcohols. However, the work-up including the separation of the mixture of the remaining substrate and the resulting compound spend a lot of time and waste much amount of solvents. On the other hand, organic synthesis based on polymer supports has made rapid progress. Although the methodology is potentially useful for the easy separation of compounds obtained by the enzymatic reaction, there have been relatively few reports on enzymatic resolutions of using a polymer so far. We have noticed that using a watersoluble polymer could be suitable for enzymatic transformation. Here, we report the first example of an enzyme-mediated enantioseleetive hydrolysis of poly（ethylene glycol）（PEG）-supported substrates with a carbonate moiety to afford optically active compounds, and the method enables us to achieve the easy separation of the products. See Scheme 1.     

Recovery Properties of Polysulfone Hollow Fiber Chelating Membrane Modified with Thiourea for Mercury （ Ⅱ ）

The adsorption isotherms of the polysulfone hollow fiber chelating membrane modified with thionrea as chelating groups for Hg^2＋ were determined. The effects of mobile phase conditions and the operating parameters on removal performance of the chelating membrane for Hg^2＋ were also investigated. The recovery of Hg^2＋ decreased at low pH and the optimum range of pH was from 6 to 7. The feed concentration effected on recovery of Hg^2＋ at the specified loading amount of Hg^2＋. The Hg^2＋ could be removed from different concentration feed solution by chelating membrane. The increase of feed flow rate led to slight decrease of recovery of Hg^2＋ at the specified loading amount of Hg^2＋. The chelating membrane could be operated at height feed flow rate and a large-scale removal of H^2＋ could be realized. With the increase of load amount, Hg^2＋ recovery decreased, but the saturation degree of chelating membrane increased. According to required recovery of H^2＋ and the saturation degree of chelating membrane, the optimum loading amount of Hg^2＋ should be selected in the actual removal of H^2＋.     

Preparation and Characterization of Nimodipine-loaded Methoxy Poly （ethylene glycol） -poly （lactic acid） Diblock Copolymer Nanoparticles

Amphiphilic diblock copolymers, methoxy poly （ ethylene glycol）-poly（lactic acid） （MePEG-PLA）, were synthesized from monomers of DL-lactide and methoxy poly （ethylene glycol） by a ring opening bulk polymerizatiou in the presence of stannous octoate. Their chemical structure and physical properties were investigated using FTIR, NMR, GPC, and fluorescence spectroscopy. To estimate the feasibility as colloidal drug carrier, nimodipine （ND） was loaded into MePEG-PLA block copolymer nanoparticles by phaseseparation/dialysis method. The mean diameter and drug loading efficiency of ND-loaded MePEG-PLA copolymer nanoparticles depended ou PLA/MePEG block composition of the copolymer and drug/polymer feed ratio in preparatiou. NMR study confirmed that nimodipine was entrapped into the hydrophobic inner core of MePEG-PLA copolymer nanoparticles and hydrophilic PEG chains were located ou the surface of the drug-loaded polymer nanoparticles. In vitro release experiments exhibited the sustained release behavior of nimodipine from MePEG-PLA copolymer nanoparticles, without any burst effect.     

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.     

Synthesis and Thermal Property of the Poly（silpheny-lenesiloxane）s with Functional Groups

1 Introduction Silicon-containing polymers have been intensively studied in the past half-century, and a great number of papers, patents and books have been published on the synthesis, properties and applications. Silicon-containing polymers, especially polymers containing silicon atoms in the backbone, including some major species as polysiloxane, polysilane, polysilazane, etc. have chains constructed of alternately arranged silicon and oxygen atoms with organic groups attached to the silicon…     

Sorption Behaviour of Acid Dyes by Soybean Protein/Poly （vinyl alcohol） Blend Fibre

The sorption behaviour of acid dyes by soybean protein/poly（vinyl alcohol） blend fibre was studied. The quantity of dye sorbed by the fibre increased markedly with the decrease in the pH of dyebath and reduced with the addition of neutral electrolyte when the pH was below 4.5, Acid dyes exhibited higher sorption rate constant and lower half dyeing time for the fibre than for spun silk and wool, which was related to the special morphological structure of the fibre, At pH 4, the sorption of disulphonated acid dyes with higher molecular weight followed the dual sorption mechanism of Langmuir plus Nernst-type partitioning well as they interacted with the fibre through electrostatic forces, hydrophobic forces and hydrogen bonds. It is considered that soybean protein and PVA components should be simultaneously dyed by disulphonated acid dyes with higher molecular weight.     

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.     

米曲霉(Aspergillus oryzae)芥子甙酶的纯化

中国是世界上油菜籽最主要的生产国之一,油菜籽经榨油后剩下的菜籽饼含有高达４０％的蛋白质及各种其它营养成份,是一种营养丰富的饲料资源．然而,菜籽饼中含有芥子甙,芥子甙在芥子甙酶（Ｍｙｒｏｓｉｎａｓｅ）的催化下,水解产生异硫氰酸酯（ＩＴＣ）、恶唑烷硫酮（...     

共聚增韧改性聚对苯二甲酸乙二酯的结构及性能研究

以对苯二甲酸二甲酯（DMT）、乙二醇（EG）和聚氧丁撑（PTMO）为原料进行共聚合，得到无规嵌段共聚物PET／PTMO。核磁共振（^1H—NMR）分析表明PTMO按投料比以化学连接的方式接到了聚合物大分子链上；DSC的结果表明PET／PTMO的熔点随PTMO含量的增加而降低，其自熔体冷却时的结晶温度Tc在PTMO含量小于8%（摩尔比）时向高温移动，而在PTMO含量为12％（摩尔比）时则小于PET的Tc；通过POM观察到，PET／PTMO所形成的球晶尺寸明显减小。将试样注塑成样条，进行抗冲击性能的测试后，发现PET／PTMO的冲击强度远大于PET，选择添加4％～8％摩尔分数的PTMO，即能显著改善韧性。     

Crystallization Behavior of Copolymer Poly(ethylene terephth-alate/isophthalate)(IPET)

The non-isothermal crystallization kinetics, isothermal crystallization and the morphology of crystals of the copolymer poly ( ethylene terephthalate/ isophthalate ) (IPET) were studied by DSC and polarized-light microscopy in this paper. DSC results indicate that the glass transition temperature Tg of IPET is slightly lower than that of poly (ethylene terephthalate) (PET), but the melting temperature Tm and the crystallization temperature Tc of PET and IPET have much difference. The difference of Tc between PET and IPET2 is about 7℃, and the difference of Tm between PET and IPET2 is about 16℃. From the kinetics analysis of the crystallization, the crystallization mechanism of all samples is of three-dimension spherulitic growth from instantaneous nuclei and the incorporation of isophthalate (IPA) decreases the crystallization rate of IPET greatly. The isothermal results indicate that the morphologies of PET and IPET crystals are all spherulite, which is in conformity to the results of non-isothermal d     

丝状真菌米曲霉外源基因表达系统的构建

以米曲霉Aspergillus oryzae RIB40的基因组DNA为模板,PCR扩增得到启动子、终止子、筛选标记基因等表达元件,依次连接到载体pUC119上,构建了米曲霉的重组表达载体pNMA. 将米赫根毛霉脂肪酶基因(RML)连接于pNMA的启动子下,得到表达载体pNMA-RML,通过ApaI酶切线性化转化米曲霉宿主菌A.oryzae niaD300,得到整合型的阳性转化子A.oryzae ONL1. 其培养7天的培养液上清在以三丁酸甘油酯为底物的平板上形成清晰的水解透明圈,碱滴定法酶活测定表明培养液酶活可达2.5 U/mL,培养液上清的SDS-PAGE图谱在32.5 kDa处有RML的特征条带. 以上结果表明RML已经在米曲霉中成功表达,同时证明所构建的米曲霉外源基因表达系统是有效的.     

聚烯烃系列/聚氧化乙烯共混材料流变行为的研究

研究了HDPE/PEO,LDPE/PEO,PP/PEO,PS/PEO共混材料的流变性。PEO具有反常流动行为,即温度越高粘度越大,这种行为仅反映在混合程度差的PP/PEO,PS/PEO共混材料中。当PEO重量分数小于或等于0.15,可改善聚烯烃系列的加工性。聚烯烃系列/PEO共混材料的表观粘度-组成曲线呈负偏差类型,与PEO是否渗出在材料表面有关,可用“可形变液滴”的两相流体模型说明。     

涤纶厂缩聚工序的监控专家系统SCPET

介绍了由酯交换法合成聚对苯二甲酸乙二醇的ＳＣＰＥＴ。结合生产工艺，对ＳＣＰＥＴ的组成和工作原理，知识库的内容和知识表达方式，推理机构等进行了探讨。     

PET/蒙脱土纳米共混体系的结构与可纺性研究

采用熔融插层法制备了聚对苯二甲酸乙二酯（PET）／蒙脱土（MMT）纳米复合材料，用广角X-射线衍射（WAXD）、透射电镜（TEM）等方法对其结构和形态进行了研究，并对PFT／蒙脱土纳米共混体系的可纺性、纺丝条件等进行了讨论。结果表明，通过提高共混的剪切效果和引入离子间相互作用可以有效地促进蒙脱土在PET基体中的插层和分散，制备出部分剥离的PFT／蒙脱土纳米复合材料，该材料具有良好的可纺性。     

聚对苯二甲酸乙二醇酯生产中终缩聚反应过程模型及其工业应用

从过程机理出发，建立了文题所述模型，在模型仿真的基础，对终缩聚过程的操作变量和产品质量指标的关系进行了详细讨论，结果对实际生产过程具有良好的指导意义。