权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Technology of crystallization of polyamide 6 via a mesophase for generation of a semicrystalline structure with specific properties. Part II: Kinetics of homogeneous nucleation

聚酰胺 6 通过中间相结晶的技术，用于生成具有特定性能的半晶结构。

基本信息

批准号：
169600666
负责人：
Professor Dr.-Ing. René Androsch
金额：
--
依托单位：
Interdisziplinäres Zentrum für Transferorientierte Forschung in den Naturwissenschaften (IWE TFN)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2010
资助国家：
德国
起止时间：
2009-12-31 至 2013-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/169600666?language=en
关键词：
Technology crystallization polyamide via mesophase

项目摘要

The supermolecular structure and properties of crystallizable polymers are strongly controlled by the pathway of crystallization. This project focuses on crystallization of polyamide 6 from the glassy state which has not been investigated in detail yet. Rapid cooling of the melt of this important polymer to ambient temperature is connected with complete vitrification of the amorphous phase, with the opportunity to generate ordered domains of variable perfection and morphology by subsequent annealing at elevated temperature. This includes the generation of non-spherulitic semicrystalline structures composed of non-lamellar crystals and amorphous phase with specific properties which cannot be obtained by melt-crystallization. In the first part of the project, the technological pre-requisites for generation of non-spherulitic semicrystalline polyamide 6 with nodular crystals were determined. In particular, the conditions of cooling the melt to obtain fully amorphous glassy samples, necessary for realization this special pathway of crystallization, were evaluated, and the effect of the conditions of annealing on cold-ordering/-crystallization was analyzed. In the second part of this project, the kinetics of homogeneous nucleation, dominating structure formation at high supercooling and being the key to obtain non-lamellar ordered domains/crystals, will quantitatively be analyzed for the first time. The analysis will be performed using the novel technique of fast scanning chip calorimetry which permits generation of amorphous states of different stability and therefore different cold-crystallization behavior/kinetics of homogeneous nucleation. Of particular importance in this project is the consideration of relaxation and ordering processes of the amorphous phase at temperature below the glass transition. The investigation of the kinetics of homogeneous nucleation, effective at high supercooling of the melt, allows gaining fundamental insights about polymer crystallization such that local ordering also occurs in the glassy state, ultimately affecting the stability of the amorphous phase and structure formation at elevated temperature. The prove of local ordering at temperatures close to the glass transition is of high application-related relevance for polyamide 6 since it is connected to physical aging and since it allows generation of materials with special properties due to the possibility for controlled structuring at the nanometer scale.

可结晶聚合物的超分子结构和性能受结晶途径的强烈控制。该项目的重点是聚酰胺6从玻璃态结晶，尚未详细研究。这种重要聚合物的熔体快速冷却至环境温度与无定形相的完全玻璃化有关，并有机会通过随后在高温下退火产生可变完美性和形态的有序域。这包括生成由非层状晶体和具有特定性质的非球晶半结晶结构，所述非球晶半结晶结构不能通过熔融结晶获得。本课题的第一部分确定了制备非球晶球状半结晶聚酰胺6的工艺条件。特别是，冷却的熔体，以获得完全无定形的玻璃样品，必要的实现这种特殊的途径的结晶的条件进行了评估，并对冷有序/结晶退火条件的影响进行了分析。在本项目的第二部分中，均匀形核的动力学，在高过冷度下的主导结构形成，是获得非层状有序域/晶体的关键，将首次定量分析。将使用快速扫描芯片量热法的新技术进行分析，该技术允许产生不同稳定性的非晶态，因此具有不同的冷结晶行为/均匀成核动力学。在这个项目中特别重要的是考虑在低于玻璃化转变温度下的非晶相的弛豫和有序过程。均匀成核的动力学，有效的熔体在高过冷的调查，允许获得有关聚合物结晶的基本见解，使本地订购也发生在玻璃态，最终影响在高温下的非晶相和结构形成的稳定性。在接近玻璃化转变的温度下局部有序的证明对于聚酰胺6具有高度的应用相关性，因为它与物理老化有关，并且由于在纳米尺度下控制结构化的可能性，它允许产生具有特殊性能的材料。