聚1-丁烯釜内合金的微观结构及其对性能的影响

对采用TiCl_4/MgCl_2-A1Et3体系制备的聚1-丁烯釜内合金的微观结构进行了表征,通过核磁共振碳谱结果计算出聚1-丁烯釜内合金中丙烯结构单元的含量。差示扫描热仪(DSC)分析表明,丙烯结构单元增加可使聚1-丁烯釜内合金从熔体中冷却结晶时,直接生成热力学稳定的晶型I,其结晶度也随之增加。力学性能测试结果表明,聚1-丁烯釜内合金的拉伸强度和弯曲模量均随丙烯结构单元含量的增加而升高。     

HDPE熔融热焓与结晶度的测定

本文简要介绍了差示扫描量热法(DSC)的工作原理,并以此来测定几种高密度聚乙烯熔体的熔融热焓和结晶度.     

微分差示扫描量热法测试PETP的结晶度

利用微分差示扫描量热曲线的玻璃化转变峰随高聚物定形含量变化的性质，测试了ＰＥＴＰ的结晶度，并与密度法结果进行了比较，两者十分吻合。试验证明，本法对于玻璃化转变峰完整规则的高聚物是完全可行的。     

氯化聚乙烯残余结晶度的测定

试验研究氯化聚乙烯（CPE）残余结晶度的测定.结果表明,用差示扫描量热（DSC）法直接对CPE样品进行残余结晶度测定,灵敏度较低,通用型CPE残余结晶度测定结果偏低;采用溶剩物-DSC法测定,可大幅提高检测灵敏度和准确性.     

聚1-丁烯的制备

采用自制的TiCl4/MgCl2-Al(i-Bu)3负载钛催化体系,合成了聚1-丁烯热塑性弹性体,考察了聚合温度对单体转化率、聚合物结构及其性能的影响。结果表明:当聚合温度为30℃时,单体转化率最高,达83％;聚合物的玻璃化转变温度最高,为-16．2℃;聚合物的回弹率最大,为25．9％;聚合物的拉伸强度最大,为15．7 MPa。     

DSC法测定聚乙烯结晶度的研究

研究了用DSC法测定聚乙烯（PE）结晶度的理论和新方法，通过X射线衍射（WAXD）及常规DSC法对测得的不同PE的结晶度进行了对比，探讨了DSC技术对测定高聚物结晶度的合理性，通过调制式DSC（MDSC）对PE热容的研究，证明了在低温下存在着小晶片的熔融，进而能显著影响所测定的PE的结晶度，最后提出了由于PE结晶度的大小与环境温度密切相关，故用DSC技术测定其结晶度时，选择基线的温度范围具有重要意义。     

聚1-丁烯的开发前景

介绍了国内外聚1-丁烯的生产、技术开发进展、市场及其应用情况,并对其在我国的发展提出了建议.     

DSC法测CPE结晶度的影响因素

探讨了仪器、样品、数据处理等测试CPE结晶度的影响因素，提出了清洗传感器、检查和校准模块等使测试结果更准确的措施。     

聚1-丁烯改性PP的研究

采用不同熔体流动速率的聚1-丁烯改性聚丙烯(PP),研究了聚1-丁烯的含量对共混物力学性能的影响。结果表明,随着聚1-丁烯加入量的增大,共混物的冲击强度和断裂伸长率明显增大,韧性得到改善,而刚性有所下降;比较发现4种聚1-丁烯中共聚聚1-丁烯对PP的增韧效果最好。     

The three-phase structure of isotactic poly(1-butene)

A detailed analysis of the three-phase structure of isotactic poly(butene) was conducted by conventional and temperature-modulated calorimetry. The development of the crystalline, mobile amorphous, and rigid amorphous fractions was analyzed as a function of thermal history, upon isothermal and non-isothermal crystallization. It was found that, under the chosen experimental conditions, the amount of rigid amorphous phase (w_RA) in PB-1 ranges from w_RA = 0.14 to 0.23, with higher values formed when the polymer is crystallized at low temperatures or at high cooling rates from the melt. Comparison of total and frequency-dependent reversing heat capacity curves suggested that the rigid amorphous phase of isotactic poly(1-butene) vitrifies after completion of the crystallization process and that its full mobilization takes place at around 50 °C. The exact temperature of complete devitrification is slightly affected by the thermal history of the material. An effort to link the mechanical properties of PB-1 to the three-phase structure was attempted, and a correlation of Young's modulus with the solid fraction at the temperature of analysis, composed of crystalline and rigid amorphous phases, was proposed.     

Self-nucleation of isotactic poly(1-butene) in the trigonal modification

Isotactic poly(1-butene) (i-PBu) is a polyolefin of industrial relevance which exhibits an interesting polymorphism. Upon cooling from the relaxed melt at atmospheric pressure, a tetragonal phase (Form II) develops. However, being metastable, this structure slowly evolves upon aging in the stable trigonal modification (Form I). Another trigonal modification, denoted Form I′, can also crystallize directly from the melt if proper conditions are met, e.g., high pressure, low tacticity, ultrathin samples etc. In this work, we aim to verify whether, by acting on the nucleation stage via a proper thermal history, the direct formation of the trigonal polymorph from the melt in a bulk sample is possible. Nucleation of i-PBu has been tailored by means of the self-nucleation technique, imposed on previously aged samples (Form I). DSC and temperature-resolved WAXS show that different crystallization pathways can be observed, depending on the residual concentration of Form I self-nuclei. With decreasing self-nucleation temperature we first encounter “cross-nucleation” of the tetragonal crystal on trigonal nuclei, followed by concomitant crystallization of Form II and Form I′ and eventually the sole formation of the trigonal modification (Form I′).     

Formation and reorganization of the mesophase of random copolymers of propylene and 1-butene

Fast scanning chip calorimetry (FSC) has been employed to study the kinetics of formation of the mesophase of random copolymers of propylene and 1-butene from the glassy amorphous state and its reorganization on heating. The experiments performed consistently prove a distinct decrease of the rate of mesophase formation with increasing concentration of 1-butene chain defects. The time required for isothermal mesophase formation at 300 K is of the order of 0.1 s in case of the homopolymer, while it is prolonged by one order of magnitude to 1 s in the copolymer with 11 mol-% 1-butene. Similar, cold-ordering of amorphous structure on continuous heating at 1000 K s⁻¹ is only completed in the homopolymer while it is almost completely suppressed in the random copolymer containing about 11 mol-% 1-butene. The perfection of the mesophase and/or its reorganization into crystals is faster in the homopolymer than in copolymers containing 1-butene. The critical heating rate for complete inhibition of perfection and reorganization is reduced from about 40,000 K s⁻¹ in the homopolymer to about 10,000 K s⁻¹ in copolymers. The reduced rate of mesophase formation in random copolymers of propylene and 1-butene is attributed to the decrease of the thermodynamic driving force for the phase transformation.     

聚1-丁烯弹性体及1-丁烯与1-己烯共聚弹性体的流变性能

采用恒速双筒毛细管流变仪研究了自制的聚1-丁烯热塑性弹性体(PB-TPE)及1-丁烯与1-己烯共聚弹性体(B-co-H)的流变性能.结果表明,相同条件下PB-TPE和B-co-H均为假塑性流体,B-co-H的非牛顿性更强,PB-TPE比B-co-H的黏流活化能高.随着1-己烯含量的增大,共聚物分子链柔顺性增加,加工性能...     

负载钛-三异丁基铝体系催化1-丁烯聚合 Ⅱ.聚1-丁烯的结构与性能

负载钛－Ａｌ（ｉ－Ｂｕ）３催化合成的聚１－丁烯,经溶剂萃取分离和１３Ｃ－ＮＭＲ测试表明为全同立构和无规立构的混合物,全同立构含量约６７％,熔点为９７℃。ＰＢｔ生胶的拉伸强度９．７ＭＰａ,断裂伸长率４９０％,永久变形小于１００％,邵尔Ａ型硬度８７,是一种热塑性弹性体材料     

陈化方式对负载钛催化合成聚1-丁烯的影响

以TiCl4(简称Ti)／Al(i-Bu)3(简称A1)为催化剂,合成了聚1-丁烯热塑性弹性体,考察了催化剂的陈化温度、陈化时间以及陈化1-丁烯(Bt)用量对转化率、聚合物重均相对分子质量的影响。结果表明．采用0℃下Ti-Al-Bt三元陈化方式制备的催化剂可以有效地提高单体的转化率,降低Al的用量。最佳陈化条件为：Bt／Ti(摩尔比)60,Al／Ti(摩尔比)20,0℃,20min。0℃陈化时,试样的重均相对分子质量比室温陈化的高;三元陈化试样的重均相对分子质量比二元陈化的高。在室温和0℃陈化时．陈化时间较短,试样的重均相对分子质量变化不大;随陈化时间的延长,试样的重均相对分子质量下降。     

三阶非线性光学材料聚氨酯-酰亚胺的合成研究

以甲苯-2,4-二异氰酸酯（TDI）和分散红-19（DR-19）合成含染料发色团的聚氨酯,进一步和二酐单体均苯四甲酸二酐（PMDA）缩合生成具有光学性能的聚氨酯-酰亚胺（PUI）;采用红外光谱（FT—IR）、示差量热扫描（DSC）、热失重分析（TGA）等手段对合成的PUI进行了表征。示差扫描量热和热失重分析结果显示,其玻璃化转变温度（％）为194℃,在5％的热失重温度为217℃,表明具有很好的热稳定性;测定了聚合物的发色团密度,其结果和理论计算值非常接近,表明聚合反应是按计量进行的;采用简单的比色法测定了聚合物材料的三阶非线性光学系数Х^（3）为2．42×10^14esu。     

复合引发剂引发GMA熔融接枝聚1-丁烯

采用复合引发剂用Haake流变仪研究了甲基丙烯酸缩水甘油酯(GMA)-苯乙烯(St)多组分单体熔融接枝高全同聚1-丁烯(iPB)。用傅里叶变换红外光谱对接枝物进行了分析,并分别考察了复合引发剂比例、GMA用量、引发剂总用量和St用量对接枝的影响。结果表明:在复合引发剂引发下,GMA和iPB可熔融接枝,接枝率最高可达1.74%;St作为共单体可明显提高GMA的接枝率和接枝效率,当n(St)/n(GMA)为1.5时,接枝率为单独使用GMA时的2.3倍。     

An AFM study on the structure and melting behavior of melt-crystallized isotactic poly(1-butene)

Spherulites with closely packed edge-on lamellae and lathlike flat-on crystals of melt crystallized isotactic poly(1-butene) in ultra-thin films at different temperatures were studied by AFM in taping mode. Starting from these different crystals, the melting processes of them after aging at room temperature for different periods of time were monitored. Through selective melting of the thermally less stable Form II crystals, the solid phase transformation of iPB-1 from Form II to I was discussed. Based on the obtained results, it is concluded that nucleation of the iPB-1 stable Form I crystals is the rate-determining step of the Form II to I conversion. Moreover, from the facts that (i) nucleation of the stable Form I crystals starts most likely at crystalline side surfaces or corners, and (ii) the phase conversion rate of the melt grown flat-on crystals is much faster than that of the solution grown single crystals, we suggest that residual local thermal stresses exist at the edges of the microcrystallites and stacking regularity of the crystalline lamellae play a very important role in generating the nuclei of the iPB-1 Form I crystals.     

聚乳酸/聚(已二酸-对苯二甲酸丁二酯)共混物的非等温结晶动力学

采用熔融挤出法制备了聚乳酸/聚(已二酸-对苯二甲酸丁二酯)共混物。利用差示扫描量热仪研究了聚乳酸及其共混体系的非等温结晶过程。用经Jeziorny修正的Avrami方程和Mo法对其非等温结晶动力学进行了分析。结果表明:Avrami方程和Mo法都适用于处理聚乳酸及其共混体系的非等温结晶过程,共混物的结晶速率大于聚乳酸的结晶速率。此外,用Huffman-Lauritzen理论计算了非等温结晶的结晶活化能,发现共混体系的结晶活化能绝对值小于聚乳酸。