新型抗静电涤纶的研制 Ⅱ.抗静电剂APPS的链结构与抗静电性能的关系及其抗静电机理

研究了抗静电剂ＡＰＰＳ分子中第三单体链段（ＰＳＩＰＥ）含量、ＰＥＧ链段含量及ＰＥＧ链段相对分子质量对ＡＰＰＳ抗静电性能的影响，同时探讨了ＡＰＰＳ的耐水洗性及其耐水洗的原因。利用扫描电子显微镜（ＳＥＭ）观察并分析了抗静电剂ＡＰＰＳ与ＰＥＴ共混后的形态结构和ＡＰＰＳ的抗静电机理。结果表明：ＰＥＴ－ＡＰＰＳ共混体系中二者呈不相容状态，ＡＰＰＳ以网络状均匀分布在ＰＥＴ基体中。ＰＳＩＰＥ链段对ＡＰＰＳ的抗静电效果影响最大，而ＰＥＧ链段含量、相对分子质量对其影响不明显。ＡＰＰＳ的耐水洗性优良而抗静电机理在于吸湿和离子导电的协同作用。     

人热休克蛋白73的基因重组、表达和纯化

目的　用基因重组的方法表达人热休克蛋白７３,并纯化表达产物,用于进一步分析。方法　用人 热休克类似蛋白ＨＳＰ７３基因构建原核细胞表达载体ｐＥＴＨＳＰ７３,在大肠杆菌ＢＬ２１中用半乳糖苷（ＩＰＴＧ）诱导表达,用 电泳法和 ＡＴＰ亲和层析法提取 ＨＳＰ７３。经ＳＤＳ－ＰＡＧＥ、用３ ａ３抗体 Ｗｅｓｔｅｒｎ ｂｌｏｔ作 ＥＣＬ检测。结果人 ＨＳＰ７３基因 构建的载体ｐＥＴＨＳＰ７３能很好地在大肠杆菌表达出相对分子质量为７３　０００的蛋白。两种蛋白提取方法均能有效提纯表达的蛋白,该蛋白具有人ＨＳＰ７３抗原特性。所得蛋白质氨基酸测定和Ｎ端测序的结果与有关的报道一致。结 论　ＨＳＰ７３基因重组、表达和纯化方法的建立,为研究ＨＳＰ７３的结构、功能与临床应用提供了必要条件。     

聚丙烯酰胺在水介质中的低温化学降解

以聚丙烯酰胺（ＰＡＭ）相对分子质量和ＰＡＭ溶液粘度为指标，讨论了聚丙烯酰胺的低温化学降解在水介质中，在过氧化物的作用下，由于化学降解反应，使得聚丙烯酰胺的相对分子质量明显下降。过氧化物的性质和浓度、降解温度和降解时间等降解条件均极大地影响聚丙烯酰胺的降解速度和降解产物的相对分子质量。对聚丙烯酰胺的水解和相应水溶液粘度的研究结果表明，在本试验条件范围内聚丙烯酰酰胺在降解过程中的水解程度很小，且少量的水解对聚丙烯胺水溶液粘度的影响不大。     

甲醛交联聚乙烯醇/麦草碱木质素发泡材料的降解性能

研究了化学降解、热降解、生物降解及紫外光降解等对甲醛交联聚乙烯醇（PVA）/麦草碱木质素发泡材料（PLFM）的力学性能和表观密度等物理性能的影响,采用红外光谱（FT-IR）、扫描电子显微镜（SEM）和热重分析（TG/DTG）等方法探讨了降解前后PLFM结构的变化。结果表明：当PLFM中碱木质素质量分数为20%时,经化学、热（150℃）、生物及紫外光降解后,拉伸强度由22.64MPa分别降为5.65、9.05、7.43和7.64 MPa,降解率分别为75.09%、60.02%、67.18%、66.25%。SEM图表明,化学降解和生物降解对PLFM闭孔结构破坏严重,紫外光降解和热降解对PLFM闭孔破坏轻微。化学降解和生物降解后,表观密度从0.183 7g/cm³分别增加到0.216 4g/cm³和0.210 4g/cm³;紫外光降解和热降解后,表观密度分别从0.183 7 g/cm³降为0.177 4和0.176 6 g/cm³。此外,FT-IR和TG/DTG分析表明：经化学、热、生物及紫外光降解后PLFM分子结构均有不同程度破坏,化学降解对PLFM结构的破坏最为严重。     

聚乙二醇改性聚乳酸幽门螺杆菌微球疫苗的制备与体外控释

目的 应用聚乳酸与聚乙二醇共聚物（ＰＥＬＡ）包裹Ｈｐ超声上清液,制备 Ｈｐ口服微球疫苗,探讨共 聚物ＰＥＬＡ总相对分子质量ｒ、ＰＥＧ含量与不同相对分子质量ＰＥＬＡ共聚物的相对分子质量分布（Ｍｒ／Ｍｎ）对微球疫 苗体外释药特性的影响。方法　采用复乳法溶剂挥发技术,制备Ｈｐ微球疫苗,用电子显微镜与扫描电镜观测微球 疫苗的粒径,用紫外光谱分光光度法测定抗原包裹效率与Ｈｐ抗原释放量,并在ｐＨ７．３、浓度为 ０．０１ｍｏｌ／Ｌ的ＰＢＳ溶 液中作体外控释实验。结果 Ｈｐ微球疫苗抗原包裹效率在７５％左右,平均粒径在５１μｍ以下。若ＰＥＧ量低于 １０％,ＰＥＬＡ组成对微球疫苗的粒径和抗原包裹效率影响不大。结论 Ｈｐ抗原体外释放量与 ＰＥＬＡ中ＰＥＧ的量和 相对分子质量、ＰＥＬＡ的相对分子质量分布成正比,而与ＰＥＬＡ的总相对分子质量成反比。     

人血管生成素基因的克隆与表达

目的 为了获得人的血管生成素基因,并在原核表达系统中进行表达。方法 利用ＲＴ－ＰＣＲ技术 从人的肝脏组织中扩增出Ａｎｇ基因片段,并将其克隆到ｐＧＥＭ－Ｔ载体中进行序列分析,再亚克隆到原核表达到 ｐＥＴ２８ａ（＋）载体中。结果　构建了重组表达载体ｐＥＴＡ,转化宿主菌ＢＬ２１（ＤＥ３）后,经ＩＰＩＧ诱导,Ａｎｇ基因蛋白在 ＢＬ２１（ＤＥ３）中表达了相对分子质量约为１７０００的重组蛋白。ＳＤＳ－ＰＡＧＥ和薄层扫描分析表明,外源蛋白的表达量 占菌体蛋白总量的１０．６４％。结论 Ａｎｇ基因的克隆与表达为进一步研究其生物活性及应用奠定了基础。     

国内外聚苯乙烯市场趋势

聚苯乙烯（ＰＳ）是为数不多的通用塑料之一。一般所讲的ＰＳ都是指无定形聚苯乙烯,最常见的有通用聚苯乙烯（ＧＰＰＳ）,抗冲级聚苯乙烯（ＩＰＳ）、高抗冲级聚苯乙烯（ＨＩＰＳ）和可发性聚苯乙烯（ＥＰＳ）［１］。１国内生产情况１９６０年我国自行设计建设了第一套...     

环氧—聚氨酯互穿聚合物网络导电涂料

研究了以环氧－聚氨酯互穿聚合物网络（ＥＰ－ＰＵＩＰＮ）为基料,镀银铜粉为导电填料的导电涂料。用扫描式电子显微镜（ＳＥＭ）观察了不同配比ＥＰ－ＰＵＩＰＮ的两相相容性,用差示扫描量热法（ＤＳＣ）测定了ＩＰＮ的玻璃化温度。讨论了ＥＰ－ＰＵＩＰＮ的结构及选择,镀银铜粉的粒度及含量对导电涂料的电阻率和使用性能的影响。试验表明,９０／１０ＥＰ－ＰＵＩＰＮ作为基料,镀银铜粉的含量为８０％、粒度为４００目,涂膜的电阻率低,使用性能好。     

第三单体SIPM对改性PET的热性能及染色性的影响

以间苯二甲酸二甲酯－５－磺酸盐（ＳＩＰＭ）为第三单体，合成了可染母粒（ＰＥＩ）。将ＰＥＩ和ＰＥＴ在真空中熔融共混，用ＤＳＣ和ＴＧＡ测定改性ＰＥＴ的热性能，并熔融纺丝测定它的染色饱和值。与无规共聚改性ＰＥＴ相比，共混改性ＰＥＴ的熔点高，热稳定性好，染色饱和值优良。     

离子型聚酯／聚酰胺6共混物的结构和性能

采用透射电子显微镜、差示扫描量热法研究了离子型聚酯（ＩＰＥＴ）／聚酰胺６体系（ＩＰＥＴ／ＰＡ６）共混物的相结构和热性能,并用Ｉｎｓｔｒｏｎ３２１１型毛细管流变仪研究了共混物的流变特性。研究表明,ＩＰＥＴ／ＰＡ６体系为热力学不相容体系,表现出两相共存的特征,分散相ＩＰＥＴ呈絮状均匀分散于ＰＡ６基体中。共混物的熔点与ＰＡ６相近,熔融焓降低。共混物熔体属切力变稀的假塑性流体。     

相对分子质量对β晶型等规聚丙烯性能的影响

利用熔体流动速率来反映等规聚丙烯(IPP)的相对分子质量,在添加自制β成核剂的条件下通过力学性能测试、差示扫描量热仪以及X射线衍射仪研究了相对分子质量对β晶型等规聚丙烯(β-PP)热行为、晶型组成和力学性能的影响。结果表明,加入β晶型成核剂后,IPP结晶温度、热变形温度均增加10℃左右,β晶型相对含量增加至60%～70%;相对分子质量较高的β-PP冲击强度提高一倍以上,相对分子质量较低的β-PP冲击性能改善有限;β-PP的弯曲模量和弯曲强度均下降,相对分子质量越低降低幅度越大。     

Thermal degradation behavior of polypropylene in the melt state: molecular weight distribution changes and chain scission mechanism

In order to clarify the effect of thermal degradation on the structure of polypropylene materials, we investigated the changes in molecular weight distribution. The samples of polypropylene were degraded iso-thermally at 190 °C at different time intervals. The molecular weight distribution was significantly changed with thermo-degradation time, and the carbonyl index increased drastically for 40 min degraded samples, where the molecular weight distribution started splitting into two peaks. The results imply that heterogeneous degradation proceeded in this system. Sequentially, the weight distribution of the oligomeric products observed was discussed on the basis of chain scissions; these results indicate that there are some kinetically favored scissions occurring near the oxygen-centered radicals.     

聚甲醛的熔融纺丝温度

通过熔融指数测定、红外光谱分析、重均相对分子质量测定、DSC测试分析了纺丝温度对聚甲醛（POM）流动性、热降解性的影响以及对POM纤维机械性能的影响,从而探讨出聚甲醛的最佳纺丝温度。结果表明：聚甲醛在高温下主要发生热氧降解,随着纺丝温度的升高,POM热降解速度加快,导致相对分子质量降低,熔点下降 ;POM的最佳纺丝温度为200℃,在此温度制备出的POM纤维强度达6.1cN/dtex.     

双组份降解地膜微生物降解性能试验

主要研究了双组份降解地膜埋土部分在热氧化、微生物的综合作用下,微生物的降解试验。未经光照的降解膜在热氧化、微生物的综合作用下均被降解,降低了分子量的聚乙烯也有被微生物降解的趋势。解决了单一组份降解地膜埋土、遮阴、水浇地部分降解不彻底、不同步的难题。     

Ultra-high modulus isotactic polypropylene. I. The influence of orientation drawing and initial morphology on the structure and properties of oriented samples

The influence of a number of factors (temperature–speed regime and the quantity of draw stages, molecular weight of a polymer, etc.) on the deformability of initial isotropic IPP and on mechanical characteristics of highly-oriented samples, obtained in the process of a two-stages isothermal orientation drawing, was studied. It was shown that the maximum achievable values of elastic modulus and draw ratio depended not only on the molecular weight of a polymer and the sizes of spherulites, constituting initial IPP, but on the structural organization of inner-and interspherulite regions. Upon physical aging of initial isotropic films, irreversible structural changes take place, which result in the formation of microvoids while being drawn and in the reduction of mechanical properties of obtained material. An extremal dependence of elastic modulus and draw ratio of maximum drawn IPP samples on draw speed was discovered. A structural model, which is supposed to possesstie molecules with various degrees of tautness in amorphous layers, was proposed. Higher effectiveness of two-stage drawing in comparison with one-stage drawing was established. The optimum temperature–speed regime of orientation drawing, which permits the reception of highly oriented, ultra-high modulus IPP with maximum high mechanical characteristics (elastic modulus ～ 30–35 GPa and tensile strength ～ 1,1 GPa), was determined.     

聚羟基丁酸酯的化学合成及生物降解性

提出了3 羟基丁酸乙酯本体聚合制备聚羟基丁酸酯(PHB)的工艺,设计了一套制备PHB的试验装置,确定了反应的试验方案。试验结果表明:在一定的反应时间范围内,随反应系统的压力降低及反应时间的延长,产物的摩尔质量逐步升高。还对化学法合成和生物发酵制备的PHB进行了生物降解性研究,确定了假单胞杆菌为降解PHB的主要菌类,化学合成的PHB可以被土壤中的细菌完全降解。     

聚乙二醇/涤纶接枝共聚固-固相转变贮热材料

为了制备热稳定性好、蓄热性能优异的固-固相转变材料(PCM),研究采用化学法合成了聚乙二醇(PEG)/涤纶(PET)PCM。实验结果表明,PEG/PET PCM的热力学性能与PEG的分子量、PEG/PET质量配比以及不同交联体系有关。化学接枝法合成的PEG/PET PCM,最大相变焓可达112.02 J/g,热稳定性提高,热滞后性减小,PEG/PET PCM在众多领域具有广泛应用。     

Kinetic and property parameters of poly(ethylene naphthalate) synthesized by solid-state polycondensation

A low molecular weight prepolymer with reactive end groups was annealed at temperatures between 200 and 245°C to obtain kinetic parameters for solid-state polymerization of poly(ethylene naphthalate) (PEN). An equation was developed to describe the relationships among time, temperature, and final molecular weight for PEN. The intrinsic viscosity and melting point during polymerization were used to monitor the molecular weight and the thermal stability of the resulting resins. The effect of moisture concentration on solid-state polymerization was also investigated. Hydrolytic degradation caused initial reductions of the molecular weight if prepolymers were solid-stated without being dried. With increased exposure to solid-state conditions, however, the hydrolytically degraded resin dried and repolymerized at rates similar to those samples that had undergone hydrolysis. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2055–2061, 2001     

Synthesis and characterization of antiseptic-based poly(anhydride-esters)

Summary Poly(anhydride-esters) were prepared from catechol, fenticlor and hexachlorophene. The molecular weights (M_w) of the polymers were typically >10,000 Da with glass transition temperatures (T_g) ranging from 23 to 84 °C. The thermal characteristics of the polymers paralleled the melting temperatures of the chemically incorporated antiseptic molecules. The in vitro release of the chemically incorporated antiseptic molecules were monitored over a 12 week period. For comparison, the in vitro release of physically admixed antiseptic molecules were also observed. After 12 weeks, the polymers were not completely degraded with drug release ranging from less than 1 to 55%. Sessile-drop contact angles indicated that the polymers were relatively hydrophobic, contributing to the slow polymer degradation rates.     

Crystallization behavior of biodegradable amphiphilic poly(ethylene glycol)‐poly(L‐lactide) block copolymers

Poly(ethylene glycol)‐poly(L ‐lactide) diblock and triblock copolymers were prepared by ring‐opening polymerization of L ‐lactide with poly(ethylene glycol) methyl ether or with poly(ethylene glycol) in the presence of stannous octoate. Molecular weight, thermal properties, and crystalline structure of block copolymers were analyzed by ¹H‐NMR, FTIR, GPC, DSC, and wide‐angle X‐ray diffraction (WAXD). The composition of the block copolymer was found to be comparable to those of the reactants. Each block of the PEG–PLLA copolymer was phase separated at room temperature, as determined by DSC and WAXD. For the asymmetric block copolymers, the crystallization of one block influenced much the crystalline structure of the other block that was chemically connected to it. Time‐resolved WAXD analyses also showed the crystallization of the PLLA block became retarded due to the presence of the PEG block. According to the biodegradability test using the activated sludge, PEG–PLLA block copolymer degraded much faster than PLLA homopolymers of the same molecular weight. © 1999 John Wiley amp; Sons, Inc. J Appl Polym Sci 72: 341–348, 1999