Thermotropic overheating protection glazings: effect of functional additives and processing conditions on the overheating protection performance

2014 ◽  
Vol 34 (2) ◽  
pp. 161-172
Author(s):  
Andreas Weber ◽  
Katharina Resch

Abstract Within this study, the effect of functional additives and processing conditions on the overheating protection performance of thermotropic systems with fixed domains (TSFD) for overheating protection purposes was evaluated. The focus was on improving the overheating protection performance of a prototype TSFD based on a UV curable acrylate resin by optimization of the material constitution (addition of functional additives like surfactants and nucleating agents) and the processing conditions (temperature conditions during manufacturing, annealing). For the evaluated system, an effect of the nucleating agent on the overheating protection performance was ascertained. Furthermore, omission of an annealing step improved the overheating protection performance slightly.

2018 ◽  
Vol 923 ◽  
pp. 56-60 ◽  
Author(s):  
Mochamad Chalid ◽  
Evana Yuanita ◽  
Ghiska Ramahdita ◽  
Jaka Fajar Fatriansyah

Impact Polypropylene Copolymer (IPC) is one of the PP type which is widely used. IPC was made with addition of ethylene in PP which decreases PP crystallinity. Many efforts have been made to improve the properties of PP crystallinity by addition of nucleating agents. In this study, we use Arenga Pinnata “Ijuk” fiber as PP nucleating agent. In order to determine the effect of “Ijuk” fiber as nucleating agents in kinetics aspect, we used DSC measurement based on Avrami equation. The results showed that the addition of ijuk decreases crystallizationhalf timeand dimension of crystal growth which indicate the effects of “Ijuk” fiber as a nucleating agent.


1984 ◽  
Vol 11 (5) ◽  
pp. 279-282 ◽  
Author(s):  
Robert L. Rietschel ◽  
Ronald Muggins ◽  
Nicole Levy ◽  
Pat M. Pruitt

2019 ◽  
Vol 56 (3) ◽  
pp. 317-341 ◽  
Author(s):  
Clemens Keilholz ◽  
Daniel Raps ◽  
Thomas Köppl ◽  
Volker Altstädt

This work focuses on the development of foamed high temperature thermoplastic substrates for printed circuit boards. For this application it is necessary to achieve mean cell diameters smaller than 30 µm in order to be able to realize vias and high packaging densities (miniaturization). Different additives as nucleating agents, namely macro- and micro-crystalline talc, silica, calcium carbonate, and wollastonite, were melt-compounded with polyetherimide using a twin-screw extruder. Foamed samples are prepared by foam extrusion using a slit die and CO2 as physical blowing agent. The aim of this study is to analyze the influence of the mean particle size and the particle surface tension on the mean cell diameters. Therefore, the shape of the additives, the foam morphology, and the elongational viscosity were considered. The additives with a suitable particle size and surface tension exhibit a positive influence on the foam morphology, resulting in smaller cell diameters (<30 µm), a narrower cell size distribution and a foam density lower than 900 kg/m3. If the mean particle diameter of the nucleating agents is lower than 0.6 µm in this study, no nucleation effect could be observed. This is related to the fact that no heterogeneous nucleation occurs, if the particle diameter is too small. If the mean particle diameter of the used additives is larger than 1.5 µm, which could be demonstrated in this study in case of polyetherimide, then the additive acts as nucleating agent and heterogeneous nucleation occurs. Furthermore, it was observed that the mean cell diameter was affected by the different surface tensions of the studied nucleating agents.


2014 ◽  
Vol 2 (1) ◽  
Author(s):  
Jennifer A. Nekuda Malik ◽  
Neil D. Treat ◽  
Maged Abdelsamie ◽  
Liyang Yu ◽  
Ruipeng Li ◽  
...  

AbstractBlending fullerenes with a donor polymer for the fabrication of organic solar cells often leads to at least partial vitrification of one, if not both, components. For prototypical poly(3-hexylthiophene):fullerene blend, we show that the addition of a commercial nucleating agent, di(3,4-dimethyl benzylidene)sorbitol, to such binary blends accelerates the crystallization of the donor, resulting in an increase in its degree of crystallinity in as-cast structures. This allows manipulation of the extent of intermixing/ phase separation of the donor and acceptor directly from solution, offering a tool to improve device characteristics such as power conversion efficiency.


2013 ◽  
Vol 873 ◽  
pp. 733-736
Author(s):  
Yi Min Wang ◽  
Hong Bo Zhang ◽  
Chun Hui Su ◽  
Qin Lei Wei

On the basis of experimental verification, the optimum processing conditions of CaO-B2O3-SiO2(CBS) system transparent glass-ceramics were obtained. Composition of main raw powders (wt%) was:CaO 38%,SiO240%,B2O312%.The precursor glass was prepared by melting method and annealed at 560°C for 2h and cooled to room temperature at a speed of 5°C/min.The best nucleating agent is P2O5. The appropriate heat treatment regime to precursor glass was determined to be 2h at 600°C for nucleation and 3h at 780°C for crystallizition.Under this condition,the transmittion of glass-ceramics at the range of visable light is 72% in average and Sm3+keep good luminescence property doped in this host material.


2013 ◽  
Vol 652-654 ◽  
pp. 463-469
Author(s):  
Li Juan Long ◽  
Wen Tao He ◽  
Min Min Zhang ◽  
Kai Zhang ◽  
Min He ◽  
...  

Substituted aromatic heterocyclic phosphate salts were synthesized by a new method and characterized by fourier transform infrared spectroscopy(FT-IR) and thermogravimetry (TG) method. The characteristic absorption bands ascribed to the stretching vibration of P=O group and P-O group verify the successful synthesis of substituted aromatic heterocyclic phosphate salts. When compared with sodium salt, the thermal stability of other salts declines. Their nucleation effects on isotactic polypropylene(iPP) were investigated with differential scanning calorimeter(DSC) and influences on mechanical, optical properties of iPP were also studied. The DSC result shows that with 0.15wt% nucleating agents incorporated into iPP, monovalent salts have a good performance, bivalent salts have less nucleation effect on the crystallization temperature. But the mass fraction of crystallinity of iPP with manganese salt could be increased by 5.2% even it has a weak ability relatively on crystallization temperature. And the mechanical and optical properties of iPP with manganese salt almost reach to iPP containing lithium salt. The results demonstrate that bivalent manganses salt is a kind of new effective nucleating agent when designing compound nucleating agents.


2014 ◽  
Vol 912-914 ◽  
pp. 445-455 ◽  
Author(s):  
Qian Wei Xu ◽  
Xian Kun Meng

Effect of nucleation agentboth on the toughness and the orientation of PET were studied. Rapid nucleationof melted PET caused by nucleating agent resulted in the decrease in grain sizeand it can improved the toughness of the PET. Both the elongation and the areaunder stress-strain curves of the PET strapping band increased significantly.Among these agents, 0.5wt% Aclyn is the most effective for elongation increaseand the tensile strength is not changed for PET/Aclyn strapping bands. Both thedecrease in orientation degree and the increase in crystallinity were observedafter adding nucleating agents in PET strapping bands. The increase in theresidual ratio of the relaxation stress with the increase of the crystallinity proved that the crystallization could inhibits thedevelopment of the stress relaxation.


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