Non-isothermal crystallization kinetics of Nylon 10T and Nylon 10T/1010 copolymers:Effect of sebacic acid as a third comonomer

Nylon 10 T and Nylon 10T/1010 samples were synthesized by direct melt polymerization. The non-isothermal crystallization kinetics of Nylon 10 T and Nylon 10T/1010 was investigated by means of differential scanning calorimetry(DSC). Jeziorny equation and Mo equation were applied to describe the non-isothermal crystallization kinetics of the Nylon 10 T and the Nylon 10T/1010. The activation energies for non-isothermal crystallization were obtained by Vyazovkin's method and Friedman's method, respectively. These results showed that Jeziorny equation and Mo equation well described the non-isothermal crystallization kinetics of the Nylon 10 T and the Nylon 10T/1010. It was found that the values of the activation energy for non-isothermal crystallization of the Nylon 10T/1010 were lower than those of the Nylon 10 T at a given temperature or relative crystallinity degree,which revealed that crystallization ability of the Nylon 10T/1010 was higher. The crystal morphology was observed by means of a polarized optical microscope(POM) and X-ray diffraction(XRD). It was found that the addition of sebacic acid comonomer not only did not change the crystal form of the Nylon 10 T, but also significantly increased the number and decreased the size of spherulites. Comparing with the Nylon 10 T, the crystallization rate was increased with the addition of the sebacic acid comonomer.

Isothermal Crystallization Kinetics of Nylon 10T and Nylon 10T/1010 Copolymers:Effect of Sebacic Acid as a Third Comonomer

Nylon 10T and nylon 10T/1010 samples were synthesized by direct melt polymerization.The isothermal crystallization kinetics of nylon 10T and nylon 10T/1010 was investigated by means of differential scanning calorimetry（DSC）.The crystallization kinetics under isothermal condition has been analyzed by the Avrami equation.It was found that the Avrami equation was well-suited to describe the isothermal crystallization kinetics,combined with the results of the Turnbull-Fisher equation.The values of Tm^0 and Kg were obtained by Hoffman-Weeks and Lauritzen-Hoffman equations,respectively.The activation energies for isothermal crystallization of nylon 10T and nylon 10T/1010 were determined using the Arrhenius equation and found to be-123.24 and-81.86 kJ·mol^（-1）,respectively,which reveals that the crystallization ability of nylon 10T/1010was lower than that of nylon 10T during the isothermal crystallization process.The crystal morphology was observed by means of polarized optical microscopy（POM）and X-ray diffraction（XRD）.It was found that the addition of sebacic acid comonomer did not change the crystal form of nylon 10T,but significantly increased the number and decreased the size of spherulites.

10-0尼龙缝线与8-0可吸收缝线在斜视手术中的应用比较

目的:探讨显微斜视术中球结膜切口使用10-0缝线与8-0可吸收缝线应用的比较。方法:选取在我院行内、外斜视手术的患者,随机分为两组,其中32例41眼(对照组)球结膜切口使用10-0缝线缝合,30例38眼(观察组)球结膜切口使用8-0可吸收缝线缝合,均采用间断、线结埋藏式缝合,对两组术后1,2wk;1mo的切口愈合情况、患者自觉刺激症状进行观察比较。结果:术后1,2wk观察组切口发生缝线吸收、切口豁开的眼数分别是7眼、15眼,总的发生率为39%,对照组无1眼发生缝线吸收、切口豁开现象,发生率为0,二者之间比较差异具有统计学意义(P<0.05);术后1mo观察组患者有33眼切口仍有缝线残留,患者眼部充血、异物感等不适建议拆线,拆线率87%;对照组在术后2wk时切口愈合良好,41眼全部拆线,拆线率100%,二者拆线率比较差异无统计学意义(P>0.05);术后切口愈合时间比较,观察组切口平均愈合时间为22.30±5.45d,对照组切口平均愈合时间为15.50±1.76d,两组比较差异有统计学意义(P<0.05);术后1,2wk两组眼部舒适度评分比较无明显差异(P>0.05),术后1mo对照组眼部舒适度评分(2.57±0.50)高于观察组(1.813±0.64),差异有统计学意义(P<0.05)。结论:显微斜视术后球结膜切口采用8-0可吸收缝线患者舒适度与10-0缝线比较并没有优势,由于缝线的过早吸收,反而出现切口的延迟愈合,建议显微斜视术后仍采用10-0缝线缝合球结膜。

蓖麻油的终端衍生产品——尼龙10与810

蓖麻油的终端衍生产品中,还有尼龙10及810,文章对它们的化工原理、生成方式、分子结构、主要设备、制取条件、物化性能、制品加工等作了简要介绍,以扩大读者对蓖麻油化工利用的视野。

杜力顿芯组使用材质对10kV避雷器性能影响分析

10 kV避雷器是低压配电网常用防雷产品,用量很大。由于低压产品技术较成熟,市场竞争力大,常用无碱玻璃纤维带浸胶后缠绕避雷器核心部件芯组,这种工艺较复杂、费时,成本较高,同时使用环氧树脂系浸胶剂,对环境也有一定的污染,因此,需要寻找一种简单实用的工艺及环保材质取代缠绕工艺。现在大多数厂家芯组改用杜力顿,而杜力顿芯组外部使用的材质制成的芯组对10 kV避雷器性能影响较大,我们根据使用不同材质PBT及尼龙PA66的性能特性,通过大量的试验,明确了不同材质对芯组性能的影响程度,尼龙PA66没有玻纤强化,容易吸水,由此制得芯组机械性能较低、容易吸潮导致电性能降低,PBT材质具有玻璃纤维强化、高阻燃性、吸水率低及介电强度高的特性,由此生产的芯组机械性能较高且具有优异的电性能,从而确定了最优材质PBT作为10 kV避雷器杜力顿芯组用材料。