scholarly journals PA6 and Halloysite Nanotubes Composites with Improved Hydrothermal Ageing Resistance: Role of Filler Physicochemical Properties, Functionalization and Dispersion Technique

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 211 ◽  
Author(s):  
Valentina Sabatini ◽  
Tommaso Taroni ◽  
Riccardo Rampazzo ◽  
Marco Bompieri ◽  
Daniela Maggioni ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Polymer Matrix ◽  
In Situ Polymerization ◽  
Cost Effective ◽  
Polyamide 6 ◽  
Halloysite Nanotubes ◽  
Amide Bonds ◽  
Molecular Weights ◽  
Dispersion Technique

Polyamide 6 (PA6) suffers from fast degradation in humid conditions due to hydrolysis of amide bonds, which limits its durability. The addition of nanotubular fillers represents a viable strategy for overcoming this issue, although the additive/polymer interface at high filler content can become privileged site for moisture accumulation. As a cost-effective and versatile material, halloysite nanotubes (HNT) were investigated to prepare PA6 nanocomposites with very low loadings (1–45% w/w). The roles of the physicochemical properties of two differently sourced HNT, of filler functionalization with (3-aminopropyl)triethoxysilane and of dispersion techniques (in situ polymerization vs. melt blending) were investigated. The aspect ratio (5 vs. 15) and surface charge (−31 vs. −59 mV) of the two HNT proved crucial in determining their distribution within the polymer matrix. In situ polymerization of functionalized HNT leads to enclosed and well-penetrated filler within the polymer matrix. PA6 nanocomposites crystal growth and nucleation type were studied according to Avrami theory, as well as the formation of different crystalline structures (α and γ forms). After 1680 h of ageing, functionalized HNT reduced the diffusion of water into polymer, lowering water uptake after 600 h up to 90%, increasing the materials durability also regarding molecular weights and rheological behavior.

Preparation and Properties of Polyamide 6-Functionalized Nanometer-Sized Graphene Composite Fiber

2012 ◽  
Vol 519 ◽  
pp. 20-23 ◽  
Author(s):  
Hai Hui Liu ◽  
Wei Wei Peng ◽  
Yong Tan ◽  
Li Chen Hou ◽  
Xing Xiang Zhang
Keyword(s):  
Polymer Matrix ◽  
Polyphosphoric Acid ◽  
In Situ Polymerization ◽  
Reaction Medium ◽  
Polyamide 6 ◽  
Composite Fiber ◽  
Pristine Graphene ◽  
Nanocomposite Fiber ◽  
Novel Approach

A novel approach to the functionalization of nanometer-sized graphene was presented in this work. Covalent bonding between the filler and matrix was formed, with minimal disruption to the sp2 hybridization of the pristine graphene sheet. Functionalization proceeded by covalently bonding a 4-substituted benzoic acid monomer to the surface of expanded graphene, via ‘‘direct Friedel-Crafts” acylation in mild reaction medium of polyphosphoric acid (PPA)/phosphorous pentoxide. Polyamide 6 (PA6)-functionalized graphene (FG) composites were prepared by in situ polymerization of ε-caprolactam in the presence of nanometer-sized FG. Nanocomposite fiber with 0.1 wt.% content of nanometer-sized FG was prepared with a piston spinning machine and hot-roller drawing machine. The nanometer-sized FG performed homogeneous dispersion in the polymer matrix. The mechanical properties of the PA6-FG composites fiber was enhanced by adding FG in the polymer matrix. The new functionalization method paves the way to prepare graphene-based nanocomposites fiber simply, without disrupting the primary structures of nanometer-sized graphene.

Synthesis and Characterizations of Poly(Butylene Succinate) Copolyester

2014 ◽  
Vol 1015 ◽  
pp. 381-384
Author(s):  
Li Liu ◽  
Li Hai Cai ◽  
Dan Liu ◽  
Jun Xu ◽  
Bao Hua Guo
Keyword(s):  
Mechanical Properties ◽  
Polymer Matrix ◽  
Crystallization Temperature ◽  
In Situ Polymerization ◽  
Nucleating Agent ◽  
Single Fiber ◽  
Butylene Succinate ◽  
Crystallization Behaviors ◽  
Polymerization Method

The poly (butylene succinate) (PBS) and 3 wt% attapulgite (ATP) reinforced PBS/ATP nanocomposites with 1,6-hexanediol were fabricated using an in situ polymerization method. The crystallization behaviors indicated that ATP had effectively acted as nucleating agent, resulting in the enhancement on the crystallization temperature. The SEM results showed a superior interfacial linkage between ATP and PBS. Also, ATP could disperse as a single fiber and embed in the polymer matrix, which resulted in the improved mechanical properties.

scholarly journals Investigation of Silicon Nanoparticle-Polystyrene Hybrids

2019 ◽  
Vol 2 (2) ◽  
pp. 49-50
Author(s):  
Madihah Khan ◽  
Alyxandra Thiessen ◽  
I Teng Cheong ◽  
Sarah Milliken ◽  
Jonathan G. C. Veinot
Keyword(s):  
Silicon Nanoparticles ◽  
In Situ Polymerization ◽  
Toxic Substance ◽  
Homogeneous Mixture ◽  
Silicon Nanoparticle ◽  
Molecular Weights ◽  
Abundant Element ◽  
The Stability ◽  
Led Lights

Current LED lights are created with quantum dots made of metals like selenium, tellurium, and cadmium which can be toxic. Silicon is used as a non-toxic substance and is the second most abundant element in the earth's crust. When silicon is prepared at a nanometer size, unique luminesce optical properties emerge that can be tuned using sized surface chemistry. Therefore, silicon nanoparticles can be used as an alternative emitter for LED lights. To produce hydride-terminated silicon nanoparticles we must synthesize the particles. Hydrogen silsesquioxane (HSQ) is processed at 1100 °C for one hour causing Si to cluster and form a SiO2 matrix, also known as the composite. The composite is then manually crushed in ethanol. The solution is further ground using glass beads, then filtered to get the composite powder. The final step is the HF etching. The hydride-terminated particles are then functionalized using three different methods to synthesize silicon nanoparticle-polystyrene hybrids, which determine the magnitude of luminosity and the quality of the hybrids. We spin coat each method and results were analyzed. Method 1 uses heat to functionalize hydride-terminated silicon nanoparticles with styrene. This process also causes styrene to attach to styrene to form a polystyrene chain. Method 1 gave a homogeneous mixture which yielded a consistent, bright and homogenous film. In method 2, dodecyl-terminated silicon nanoparticles are mixed with premade polystyrene. While this method gave better control of the amount of silicon nanoparticles inside the polymer hybrid, a homogeneous mixture was not created due to the different structures of polystyrene and dodecyl chains. Method 3 has dodecyl-terminated silicon with in-situ styrene polymerization. It generated a homogeneous mixture. The in-situ polymerization stabilizes the particles, allowing for brighter luminescence. Because of the stability and lower molecular weight, the mixture was easier to dissolve. We concluded that the different methods resulted in different polymer molecular weights and this created distinct properties between the polymer hybrids when spin-coating.    

Nanocomposites of polypropylene with halloysite nanotubes employing in situ polymerization

2016 ◽  
Vol 74 (7) ◽  
pp. 2447-2464 ◽  
Author(s):  
Maria de Fátima Vieira Marques ◽  
Jefferson Luis da Silva Rosa ◽  
Marcelo Cosme Vasconcelos da Silva
Keyword(s):  
In Situ Polymerization ◽  
Halloysite Nanotubes

scholarly journals The Effect of the Parameters of T-RTM on the Properties of Polyamide 6 Prepared by in Situ Polymerization

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 4 ◽  
Author(s):  
Orsolya Viktória Semperger ◽  
András Suplicz
Keyword(s):  
Mechanical Properties ◽  
Automotive Industry ◽  
Cycle Time ◽  
In Situ Polymerization ◽  
Rapid Development ◽  
Polyamide 6 ◽  
Raw Material ◽  
Short Cycle ◽  
Short Cycle Time

With the rapid development of the automotive industry, there is also a significant need to improve the raw materials used. Therefore, the demand is increasing for polymer composites with a focus on mass reduction and recyclability. Thermoplastic polymers are preferred because of their recyclability. As the automotive industry requires mass production, they require a thermoplastic raw material that can impregnate the reinforcement in a short cycle time. The most suitable monomer for this purpose is caprolactam. It can be most efficiently processed with T-RTM (thermoplastic resin transfer molding) technology, during which polyamide 6 is produced from the low-viscosity monomer by anionic ring-opening (in situ) polymerization in a tempered mold with a sufficiently short cycle time. Manufacturing parameters, such as polymerization time and mold temperature, highly influence the morphological and mechanical properties of the product. In this paper, the properties of polyamide 6 produced by T-RTM are analyzed as a function of the production parameters. We determine the crystallinity and the residual monomer content of the samples and their effect on mechanical properties.

Features of forming the structure and properties of polyamide-6 via in situ polymerization with oxidized graphite

2020 ◽  
Vol 27 (9) ◽  
Author(s):  
Dmitriy Leonov ◽  
Tatiana Ustinova ◽  
Natalia Levkina ◽  
Anton Mostovoy ◽  
Marina Lopukhova
Keyword(s):  
In Situ Polymerization ◽  
Polyamide 6 ◽  
Structure And Properties ◽  
Oxidized Graphite

scholarly journals Characterization of Polyamide 6/Multilayer Graphene Nanoplatelet Composite Textile Filaments Obtained Via In Situ Polymerization and Melt Spinning

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1787
Author(s):  
Jelena Vasiljević ◽  
Andrej Demšar ◽  
Mirjam Leskovšek ◽  
Barbara Simončič ◽  
Nataša Čelan Korošin ◽  
...  
Keyword(s):  
Melt Spinning ◽  
In Situ Polymerization ◽  
Complex Viscosity ◽  
Polyamide 6 ◽  
High Dispersion ◽  
Multilayer Graphene ◽  
Main Challenge ◽  
Dispersion State ◽  
Continuous Filament

Studies of the production of fiber-forming polyamide 6 (PA6)/graphene composite material and melt-spun textile fibers are scarce, but research to date reveals that achieving the high dispersion state of graphene is the main challenge to nanocomposite production. Considering the significant progress made in the industrial mass production of graphene nanoplatelets (GnPs), this study explored the feasibility of production of PA6/GnPs composite fibers using the commercially available few-layer GnPs. To this aim, the GnPs were pre-dispersed in molten ε-caprolactam at concentrations equal to 1 and 2 wt %, and incorporated into the PA6 matrix by the in situ water-catalyzed ring-opening polymerization of ε-caprolactam, which was followed by melt spinning. The results showed that the incorporated GnPs did not markedly influence the melting temperature of PA6 but affected the crystallization temperature, fiber bulk structure, crystallinity, and mechanical properties. Furthermore, GnPs increased the PA6 complex viscosity, which resulted in the need to adjust the parameters of melt spinning to enable continuous filament production. Although the incorporation of GnPs did not provide a reinforcing effect of PA6 fibers and reduced fiber tensile properties, the thermal stability of the PA6 fiber increased. The increased melt viscosity and graphene anti-dripping properties postponed melt dripping in the vertical flame spread test, which consequently prolonged burning within the samples.

scholarly journals Delaminated Polymer/Lamellar Aluminophosphate Nanocomposites Prepared via in SITU Polymerization

2006 ◽  
Vol 15 (5) ◽  
pp. 096369350601500 ◽  
Author(s):  
Jingyu Wang ◽  
Guoping Chen ◽  
Quan Zhou
Keyword(s):  
Polymer Matrix ◽  
In Situ Polymerization ◽  
Short Chain ◽  
Long Chain

A method to synthesize completely delaminated polymer/lamellar aluminophosphate (Mu-4) nanocomposites has been successfully developed, wherein organo-modification of Mu-4 followed by in situ polymerization was applied. It can be found that the long chain n-dodecylamine molecules can favor the intercalation of Mu-4 and thus readily make the Mu-4 layers delaminated in the polymer matrix compared with the short chain N,N-dimethylpropane-1,3-diamine.

Study of the Proper Sintering Conditions of Anionically-Polymerized Polyamide 6 Matrices for the Fabrication of Greencomposites

2012 ◽  
Vol 713 ◽  
pp. 121-126
Author(s):  
A. Alfonso ◽  
J. Andrés ◽  
J.A. García
Keyword(s):  
Material Characterization ◽  
Mechanical Performance ◽  
In Situ Polymerization ◽  
Research Work ◽  
Polyamide 6 ◽  
Liquid Composite Molding ◽  
Thermoplastic Matrix ◽  
Composite Molding ◽  
Long Fiber Thermoplastic

The present research work assesses the manufacture of long fiber thermoplastic matrix composite materials (GreenComposites). Thermoplastic matrices are too viscous to be injected into the conventional LCM (Liquid Composite Molding) molds, and then epoxy, polyester or vinylester resins are used. Nevertheless, the groundbreaking anionic polymerization of caprolactam allows such a synthesis of a thermoplastic APA6 matrix inside the mold. This matrix is sintered from the starting monomers, and presents high mechanical performance and recyclability. In order to do the reactive injection in a LCM mold, it is necessary to control the polymerization mechanism of such a thermoplastic matrix. This paper puts special emphasis on detecting and solving all problems which arose during synthesis. For instance, moisture values were assessed for all starting reactants, since humidity keeps polymerization from occurring. It is thought that once the synthesis and the resulting material characterization are well controlled, the manufacture of GreenComposites through in situ polymerization, as well as addition of state-of-the-art fabrics such as basalt, can proceed successfully.

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