Halogen‐free intumescent flame retardancy and mechanical properties of the microcellular polypropylene with low expansion ratio via continuous extrusion assisted by subcritical CO 2

2021 ◽  
pp. 51971
Author(s):  
Yichen Tian ◽  
Changjing Gong ◽  
Hongfu Zhou ◽  
Ziyin Jiang ◽  
Xiangdong Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flame Retardancy ◽  
Expansion Ratio ◽  
Continuous Extrusion ◽  
Intumescent Flame Retardancy ◽  
Halogen Free

scholarly journals Production and Processing of a Spherical Polybutylene Terephthalate Powder for Laser Sintering

2019 ◽  
Vol 9 (7) ◽  
pp. 1308 ◽  
Author(s):  
Rob Kleijnen ◽  
Manfred Schmid ◽  
Konrad Wegener
Keyword(s):  
Mechanical Properties ◽  
Thermal Processing ◽  
Selective Laser Sintering ◽  
Spherical Shape ◽  
Laser Sintering ◽  
Polybutylene Terephthalate ◽  
Powder Production ◽  
Injection Molded ◽  
Continuous Extrusion ◽  
Matrix Powder

This work describes the production of a spherical polybutylene terephthalate (PBT) powder and its processing with selective laser sintering (SLS). The powder was produced via melt emulsification, a continuous extrusion-based process. PBT was melt blended with polyethylene glycol (PEG), creating an emulsion of spherical PBT droplets in a PEG matrix. Powder could be extracted after dissolving the PEG matrix phase in water. The extrusion settings were adjusted to optimize the size and yield of PBT particles. After classification, 79 vol. % of particles fell within a range of 10–100 µm. Owing to its spherical shape, the powder exhibited excellent flowability and packing properties. After powder production, the width of the thermal processing (sintering) window was reduced by 7.6 °C. Processing of the powder on a laser sintering machine was only possible with difficulties. The parts exhibited mechanical properties inferior to injection-molded specimens. The main reason lied in the PBT being prone to thermal degradation and hydrolysis during the powder production process. Melt emulsification in general is a process well suited to produce a large variety of SLS powders with exceptional flowability.

Expanded vermiculite-filled flexible polymer composites

2021 ◽  
pp. 009524432110290
Author(s):  
Mukaddes Sevval Cetin ◽  
Ozan Toprakci ◽  
Omer Suat Taskin ◽  
Abdullah Aksu ◽  
Hatice Aylin Karahan Toprakci
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Contact Angle ◽  
Polymer Composites ◽  
Flame Retardancy ◽  
Composite Films ◽  
Filler Concentration ◽  
High Shear ◽  
Flexible Polymer ◽  
Shear Mixing

This study focuses on the fabrication and characterization of vermiculite-filled flexible polymer composites. Exfoliated vermiculite was incorporated into triblock thermoplastic elastomer copolymer, styrene- b-(ethylene- co-butylene)- b-styrene (SEBS), at various levels from 1 to 15 wt% by a high shear mixer. The composite films were obtained by the combination of solvent casting and compression molding. The morphological, structural, thermal, and mechanical properties and contact angle of the composites were determined. Some micro-morphological differences were observed between the samples and the difference was assumed to be caused by high shear mixing and filler concentration. High shear mixing was found effective in terms of the detachment of vermiculite layers at all concentrations. However, at low filler loading, that behavior was more obvious. At 1 wt% filler concentration, mechanical properties increased that was probably caused by good filler-matrix interaction stemmed from smaller particle size. At higher vermiculite concentrations, fillers found to show agglomerations that led to a decrease in mechanical strength and strain at break. Elastic and secant modulus showed an increasing trend. Contact angle measurements were carried out to determine the oleophilic character of the samples. An increase in the vermiculite content resulted in higher oleophilic character and the lowest contact angle was obtained at 15 wt% VMT loading. In addition to these, thermal stability, thermal dimensional stability and flame retardancy were improved by the incorporation of VMT. 15 wt% vermiculite-filled sample showed the best performance in terms of thermal stability and flame retardancy.

An efficient method to improve simultaneously the water resistance, flame retardancy and mechanical properties of POE intumescent flame-retardant systems

RSC Advances ◽  
2015 ◽  
Vol 5 (21) ◽  
pp. 16328-16339 ◽  
Author(s):  
Rui-Min Li ◽  
Cong Deng ◽  
Cheng-Liang Deng ◽  
Liang-Ping Dong ◽  
Hong-Wei Di ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Efficient Method ◽  
Water Resistance ◽  
Intumescent Flame Retardant

The water resistance, flame retardancy and mechanical properties of POE intumescent flame-retardant systems were improved simultaneously.

scholarly journals Progress in Biodegradable Flame Retardant Nano-Biocomposites

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 741
Author(s):  
Zorana Kovačević ◽  
Sandra Flinčec Grgac ◽  
Sandra Bischof
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Circular Economy ◽  
Nanocomposite Materials ◽  
Thermal And Mechanical Properties ◽  
Specific Group ◽  
New Class ◽  
Research Initiatives ◽  
Positive Properties

This paper summarizes the results obtained in the course of the development of a specific group of biocomposites with high functionality of flame retardancy, which are environmentally acceptable at the same time. Conventional biocomposites have to be altered through different modifications, to be able to respond to the stringent standards and environmental requests of the circular economy. The most commonly produced types of biocomposites are those composed of a biodegradable PLA matrix and plant bast fibres. Despite of numerous positive properties of natural fibres, flammability of plant fibres is one of the most pronounced drawbacks for their wider usage in biocomposites production. Most recent novelties regarding the flame retardancy of nanocomposites are presented, with the accent on the agents of nanosize (nanofillers), which have been chosen as they have low or non-toxic environmental impact, but still offer enhanced flame retardant (FR) properties. The importance of a nanofiller’s geometry and shape (e.g., nanodispersion of nanoclay) and increase in polymer viscosity, on flame retardancy has been stressed. Although metal oxydes are considered the most commonly used nanofillers there are numerous other possibilities presented within the paper. Combinations of clay based nanofillers with other nanosized or microsized FR agents can significantly improve the thermal stability and FR properties of nanocomposite materials. Further research is still needed on optimizing the parameters of FR compounds to meet numerous requirements, from the improvement of thermal and mechanical properties to the biodegradability of the composite products. Presented research initiatives provide genuine new opportunities for manufacturers, consumers and society as a whole to create a new class of bionanocomposite materials with added benefits of environmental improvement.

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