尼龙6微孔发泡材料的制备及泡孔形貌调控

本文利用共混改性方法得到高熔体强度尼龙6基体,通过探索不同的工艺条件,获得不同倍率的尼龙6发泡材料,系统研究不同离聚体改性剂比例下对其熔体强度的影响.通过热性能测试和流变测试推测了其中微交联结构的存在.通过调节发泡工艺制备不同发泡倍率的尼龙6发泡材料,用扫描电镜(SEM)观测泡孔形貌.结果 表明,离聚体的加入大大提升尼龙6基体的熔体强度,实现了尼龙6超临界二氧化碳发泡的可能性,并获得了较大倍率的尼龙发泡材料.     

高温熔体粘度测试仪的温度控制技术

介绍了高温熔体粘度测试仪的组成和功能.分析了高温熔体粘度测试仪温度控制系统的特点.为了提高加热速度和温度控制精度,提出了阈值控制策略与自适应模糊PID控制相结合的控制算法.在高温炉当前温度值与设定温度值偏差较大时,为了保护系统和提高加热速度,运用阙值控制策略对系统进行控制,在高温炉当前温度值与设定温度值偏差较小时,运用自适应模糊PID控制,以保证控制精度.仿真研究和试验测试证明,该控制算法在保证控制精度的基础上,能很好地提高系统的动态性能.     

Toughening of polycarbonate through reactive melt blending: Effect of hydroxyl content and viscosity of hydroxyl-terminated polydimethysiloxane

In this study, four hydroxyl-terminated polydimethylsiloxanes(PDMSOH) with different viscosities and hydroxyl contents were used to improve the toughness of polycarbonate(PC) through reactive melt blending. A largely improved toughness of PC has been achieved, and the low temperature toughness of PC/PDMSOH blends could overtake that of PC homopolymer in much higher temperatures(e.g.-10 °C versus 23 °C). Moreover, it was found that the more the hydroxyl content, the less the PDMSOH was needed to reach the highest toughness, suggesting that equivalent molar ratio between the carbonyl group content of PC and the hydroxyl group content of PDMSOH was required for the toughening of PC. Ultraviolet spectrophotometry was used to analyze the possible reaction between PC and PDMSOH. Contact angle was measured to assess the change of interfacial interaction between PC and PDMSOH as change of viscosity and hydroxyl content. The formation of PC-co-PDMSOH copolymer was believed to be the key for the toughening effect. This work gives a profound recommendation of the optimum kind and dosage of PDMSOH which should be used to improve the toughness of PC and will find immediate industrial applications.     

Effect of Molecular Weight on the Properties of Poly（butylene succinate）

Poly（butylene succinate） （PBS） with different molecular weight was synthesized from 1, 4-butanediol and succinic acid by direct melt condensation. The synthesized PBS was identified by IH-NMR and FTIR spectrometry. The molecular weight was calculated from the intrinsic viscosity, and its value was between 20000 and 70000. The crystallization behavior and crystal morphology as function of molecular weight were investigated by DSC and PLM, respectively. The mechanical properties and hydrolytic degradation behaviors related with change of molecular weight were also studied in this work. The results demonstrated that the properties of PBS were determined by both molecular weight and crystallization properties （crystallinity as well as crystal morphology）. Our work is important for the design and preparation of PBS with proper molecular weight for its practical application.     

Miscibility between PS and PSAN Affected by Solvent and Temperature of the System

The influence of solvent on the miscibility of polystyrene（PS） and poly（styrene-co-acrylonitrile）（PSAN） blends has been investigated viscometrically. The miscibility of different PS/PSAN blend（30/70, 50/50 and 70/30） compositions in acetone and benzene at 20, 30, and 40 °C was investigated on the basis of the sign of Chee（ΔB and ）, and Sun’s（α） criteria. The values of these parameters were evaluated from the analyses of reduced viscosity data of binary（solvent/polymer） and ternary（solvent/polymer1/polymer2） polymer systems. These investigations indicated partial miscibility for both the blend systems. However, PS/PSAN/acetone blend system showed somewhat higher partial miscibility than the PS/PSAN/Benzene blend system highlighting the impact of solvent over the polymer-polymer interactions and hence their miscibility. The results obtained through viscometry were also corroborated by the refractive index and density results for the blends under study. The effect of temperature on miscibility in both the cases was almost negligible.     

用单管落球法探讨蓖麻油粘度随温度的变化

从单管落球法出发,以测出蓖麻油粘度随温度变化的大量实验数据为基础,采用SPSS统计软件中线性回归与曲线拟合的方法,选择最佳统计模型,找到了两者之间的实验曲线及拟合方程.     

聚乙烯基正丁基醚的应用探讨

粘度指数改进剂是润滑油的重要添加剂。综合介绍粘度指数改进剂的作用机理、种类、发展概况和使用性能,结合聚乙烯基正丁基醚粘度指数改进剂T601(BB)的性能特点,重点分析了BB在工业齿轮油和10号航空液压油中应用情况和影响。     

Sn的质量分数对Bi-Sn合金熔体结构的影响

用相对能量耗散方法在升温过程中对纯Bi、纯Sn及Bi-Sn合金熔体进行了较系统地研究。结果表明,随着Sn质量分数的不同,熔体表现出不同的相对能量耗散行为;富Sn合金熔体的相对能量耗散行为与纯Sn相似,富Bi合金熔体的相对能量耗散行为与纯Bi相似。     

环化顺1，4－聚丁二烯浓溶液的流动行为

大多数线型高聚物浓溶液的流动行为呈现非牛顿性，线型顺１，４－聚丁二烯（ＬＢＲ）亦然，而环化顺１，４－聚丁烯（ＣＢＲ）的浓溶液在浓度达１７．８％时仍表现为牛顿流体。ＣＢＲ溶液的临界缠结浓度明显地高于ＬＢＲ，ＣＢＲ分子链间的缠结效应比ＬＢＲ弱得多，这是ＣＢＲ的分子链结构特征所致。     

4-苯乙炔基苯胺封端聚酰亚胺树脂的合成与性能研究

使用4-苯乙炔基苯胺(4-PEA)作为反应性封端剂,和3,3′,4,4′-二苯醚四酸二酐(ODPA),3,3′,4,4′-联苯四酸二酐(BPDA),1,4-双(4′-氨基-2′-三氟甲基苯氧基)苯(BTPB)和3,4′-二氨基二苯醚(3,4-′ODA)反应合成了系列4-苯乙炔基苯基封端的聚酰亚胺低聚物,对低聚物的化学结构、热性能和熔体粘度以及固化后树脂的热性能等进行了研究.实验结果表明,低聚物均具有一定的结晶性,含有ODPA的聚酰亚胺低聚物较之含有BPDA的低聚物具有更低的熔体粘度,且出现最低熔体粘度的温度更低;固化后的树脂表现出良好的热性能,含有BPDA的树脂具有更高的玻璃化转变温度;系列低聚物中二胺单体的比例对于低聚物的熔体粘度和固化后树脂的热稳定性有一定影响.