三箱式纺丝技术生产PET/PA6复合纤维

介绍了采用三箱式纺丝技术生产PET/PA6复合纤维的设备及工艺。重点对纺丝箱体、纺丝温度控制进行了详细的讨论。     

Pt/C活性催化剂催化氢化合成6-氯-2-羟基喹喔啉

以对氯邻硝基乙酰乙酰苯胺为原料，在碱性条件下经环合及催化氢化合成6-氯-2-羟基喹喔啉。采用自制的Pt／C催化剂，考察了反应条件对产品收率的影响，在85℃，1．0～1．3MPa氢气压力下进行加氢还原反应，总收率89．6％(以对氯邻硝基乙酰乙酰苯胺转化为6-氯-2-羟基喹喔啉)。     

2,6-二乙酰基吡啶合成方法的改进

优化了2，6—二乙酰基吡啶的合成工艺。以2，6—吡啶二羧酸为原料，经过醇化及克莱森酯缩合反应，合成了2，6—二乙酰基吡啶，2，6—吡啶二羧酸二乙醇和2，6—二乙酰基吡啶的分离收率分别为94．1％和88．9％，2，6—二乙酰基毗啶的质量分数大于99％。     

6，7-二氢-5H-环戊烷并[b]吡啶

6,7-二氢-5H-环戊烷并[b]吡啶主要用于药物、杀菌剂和抗菌剂的研究,也被广泛应用于制备植物保护剂和合成树脂、防老剂以及塑料制品等。目前因其被作为第四代抗生素头孢匹罗的侧链而成为研究者竞相开发的热点。6,7-二氢-5H-环戊烷并[b]吡啶有实用价值的合成方法主要有N-羟基邻苯二甲酰胺法、丙烯醛法和己二酸二乙酯法。丙烯醛法中6,7-二氢-5H-环戊烷并[b]吡啶的收率为87.4%,具有较好的开发前景。     

4-(6′甲基苯并噻唑-2′-偶氮)-3,5-二氨基吡唑与钯显色反应的研究和应用

对6种苯并噻唑偶氮吡唑化合物的分析特性进行了探讨,着重研究了4—(6′—甲基苯并噻唑-2′-偶氮)-3,5-二氨基吡唑(MBTAP)与钯离子显色反应的光度性质。在非离子表面活性剂 Brij35存在下与钯离子形成橙红色的配合物。适宜的 pH 值范围为9.0～10.5.配合物的最大吸收波长为510nm,表观摩尔吸光系数为3.01×10~4L·mol~(-1)·cm~(-1)。钯在0～14μg/25mL,范围内服从比尔定律.显色体系可稳定11h。在柠檬酸存在下可消除 Fe~(3+)、Co~(2+)、Cu~(2+)、Ni~(2+)等离子的干扰。     

FT-IR spectroscopic study of hydrogen bonding in PA6/clay nanocomposites

Fourier transform infrared spectroscopy was used to investigate PA6/clay nanocomposites (PA6CN) with various cooling histories from the melt, including rapid cooling (water-quenched), middle-rate cooling (air-cooling) and slow cooling (mold-cooling). In contrast to pure PA6 dominated by the α-phase, the addition of clay silicate layers favor the formation of the γ-crystalline phase in PA6CN.We focus on the reason why silicate layers favor the formation of γ-phase in PA6. Vaia et al. suggested that the addition of clay layers forces the amide groups of PA6 out of the plane formed by the chains. This results in conformational changes of the chains, which limits the formation of H-bonded sheets so that the γ-phase is favored. If this assumption is correct, PA6CN is expected to show some differences as compared with PA6 with respect to hydrogen bonding.The silicate layers were indeed found to weaken the hydrogen bonding both in the α- and γ-phases. This was also confirmed by X-ray diffraction studies. The γ-phase is most likely concentrated in regions close to the silicate layers, whereas the α-phase is favored in the bulk matrix.     

Crystallization,morphology, structure and thermal behaviour of nylon-6/rubber blends

An experimental study was carried out in order to investigate the morphological, kinetic, structural and thermodynamic properties of nylon-6/rubber (namely ethylene-propylene copolymer (EPM) and ethylene-propylene copolymer functionalized by inserting along its backbone succinic anhydride groups (EPM-g-SA)) blends. The morphology and the overall kinetics of crystallization of the blends strongly depend on the type of copolymer added to nylon and on the blend composition. The EPM-g-SA acts as a nucleating agent for the Ny spherulites and at the same time causes a drastic depression of the overall kinetic rate constant. This decrease is related to the increase of the melt viscosity observed in Ny/EPM-g-SA blends. The crystalline lamella thickness of the Ny phase in the blends is lower than that of pure Ny crystallized at the same T_c suggesting that the presence in the melt of an elastomeric phase disturbs the growth of the Ny crystals. The rubber does not influence the thermal behaviour of the nylon. The results found lead to the conclusion that in the melt nylon-6 is incompatible with both EPM and EPM-g-SA copolymers.     

原位聚合制备尼龙6/纳米SiO2复合材料研究

对原位聚合制备尼龙6／纳米SiO2进行研究。结果表明，无论是否对纳米SiO2复合材料进行偶联化处理，其表面均将在原位聚合过程中与尼龙6产生接枝；SiO2表面接枝物的生成，可在某种程度上造成体系结晶程度的降低，但复合体系的力学性能主要由SiO2粒子的分散程度、粒子和其体之间的相界面性质等因素决定；采用经偶联剂处理并具有较小粒径和较大比表面积的SiO2对尼龙6进行复合，可使复合体系的力学性能指标达到较高的水平，且硅烷偶联剂的最佳用是为SiO2的3％左右。