On the correlation between characteristics of topological and molecular structures and mechanical properties of NR/chlorinated polyethylene rubbers

2003 ◽  
Vol 90 (9) ◽  
pp. 2583-2591 ◽  
Author(s):  
Barbara Jurkowska ◽  
Boleslaw Jurkowski
Keyword(s):  
Mechanical Properties ◽  
Molecular Structures ◽  
Chlorinated Polyethylene

scholarly journals A method for pet mechanical properties enhancement

2019 ◽  
Vol 10 (8) ◽  
pp. 1725
Author(s):  
Raffaella Aversa ◽  
Relly Victoria Virgil Petrescu ◽  
Antonio Apicella ◽  
Florian Ion Tiberiu Petrescu
Keyword(s):  
Mechanical Properties ◽  
Liquid Crystalline ◽  
Liquid Crystalline Polymers ◽  
Molecular Structures ◽  
Reactive Blending ◽  
Scanning Calorimetry ◽  
Shear Transfer ◽  
Crystalline Polymers ◽  
Reactive Compatibilizer

A method for PET mechanical properties enhancement by reactive blending with HBA/HNA Liquid Crystalline Polymers for in situ highly fibrillar composites preparation is presented. LCP/PET blends were reactively extruded in presence of Pyromellitic Di-Anhydride (PMDA) and then characterized by Differential Scanning Calorimetry, Thermally Stimulated Currents and tensile mechanical properties. Moderate amounts of LCP in the PET (0.5 and 5%) and small amounts of thermo-active and reactive compatibilizer in the blend (0.3%) were found to significantly improve LCP melt dispersion, melts shear transfer and LCP fibril formation and adhesion. An unexpected improvement was probably due to the presence of two distinct phases’ supra-molecular structures involving PET-LCP and PMDA.

Effect of Blending with Additives on Mechanical Properties of PVC Architectural Membrane Material

2011 ◽  
Vol 687 ◽  
pp. 617-620 ◽  
Author(s):  
Yu Gang Meng ◽  
Rui Ting Huo ◽  
Chun Zhi Qi ◽  
Ling Yu Chang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Mechanical Characteristics ◽  
Peel Strength ◽  
Pvc Membrane ◽  
Membrane Material ◽  
Chlorinated Polyethylene ◽  
Coated Fabric ◽  
Tearing Strength ◽  
Trimethoxy Silane

Polyvinyl chloride (PVC) architectural membrane material is a species of composite textile material. In comparison with other architectural membrane materials such as PTFE or ETFE, PVC membrane material is much cheaper, softer and easier construction feasibility. In this paper, g-methacryloxypropyl trimethoxy silane (KH-570), chlorinated polyethylene (CPE) and pellet binder (PB) were added into PVC paste, respectively. The mechanical properties (tensile strength, peel strength and tearing strength) of the coated fabric were investigated. It was found that the mechanical characteristics of PVC coated fabric were evidently affected by the addition of KH-570 in the coating paste. Both tensile strength and peel strength of PVC coated fabric were improved by the addition of KH-570. The addition of CPE into the coating paste had little effect on the mechanical properties of the coated fabric. The mechanical properties of the coated fabric were greatly improved by blending with PB, the peel strength enhanced 157% and the tensile strength increased 150N/50mm, but the tearing strength was largely reduced.

Effect of chain extender on the mechanical and thermal resistance properties of polyurethane liners for composite propellants

Polyurethanes ◽  
2016 ◽  
Vol 1 (1) ◽  
Author(s):  
P. Ross ◽  
G. Sevilla ◽  
J. Quagliano
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Chain Extender ◽  
Molecular Structures ◽  
Polymer Chains ◽  
Mechanical And Thermal Properties ◽  
Thermal Changes ◽  
Ft Ir ◽  
Chain Lengths

AbstractPolyurethane formulations utilized as liners for composite propellants were prepared by the reaction of toluene-2,4-diisocyanate (TDI) and isophorone diisocyanate (IPDI) with hydroxyl terminated polybutadiene (HTPB), while polymer chains were further extended with neopentyl glycol diol, NPG triol and two different triols (monoglyceryl ricinoleate, MRG and trimethylolpropane, TMP). Liners were formulated with micronized titanium dioxide mechanically dispersed in hydroxyl-terminated polybutadiene (HTPB). The molecular structures of liners were confirmed by FT-IR. Thermal properties indicated that the nature of chain extender (crosslinker) only slightly affected the temperatures for decomposition of liners. Two main thermal changes were found at 370∘C and another at around 440–500∘C, depending on the chain extender utilized. On the other side, mechanical properties varied within the range of 0,7-1,8 MPa, consistent with this kind of elastomers. Tensile strength at break was only significantly affected with TMP and MRG-chain extended liners at the lowest concentrations tested of 1,3 and 2% (w/w), respectively. However, the behaviour depended on whether TDI or IPDI isocyanate was utilized for curing. TMP 1,3% crosslinked liner cured with TDI had a tensile strength of 1,82MPa whileMRG-crosslinked liner cured with IPDI had a tensile strength of 1,56 MPa. It was observed that at the higher NCO/OH ratios essayed, tensile strength and hardness increased, improving mechanical properties. Our results confirmed that TMP and MRG triols together with NPG diols can be used to tailor mechanical and thermal properties of liners, considering their different hydroxyl functionalities and chain lengths.

scholarly journals Mechanical and electrical properties of polylactic acid/carbon nanotube composites by rolling process

2018 ◽  
Vol 25 (5) ◽  
pp. 891-901 ◽  
Author(s):  
Lijun Wang ◽  
Jianhui Qiu ◽  
Eiichi Sakai
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotube ◽  
Electrical Properties ◽  
Polylactic Acid ◽  
Molecular Orientation ◽  
Rolling Direction ◽  
Rolling Process ◽  
Molecular Structures ◽  
Scanning Calorimetry ◽  
Mechanical And Electrical Properties

AbstractIn this work, the rolling process was employed to fabricate polylactic acid/multi-walled carbon nanotube (PLA/MWCNT) composites at room temperature. The effects of the rolling conditions on the mechanical and electrical properties of the fabricated composites were investigated. The evolution processes of the internal molecular structures, i.e. changes in molecular orientation and crystallinity, were examined by X-ray diffraction, differential scanning calorimetry, and density method. The results suggested that the molecular orientation improved; however, the crystallinity decreased when the rolling ratio increased. The analysis of the mechanical properties revealed that the rolled composites displayed anisotropy during the rolling process. In the rolling direction, after adding 1 wt.% MWCNTs, the tensile strength increased from 58.6 to 94.3 MPa with the rolling ratio, whereas the fracture strain sharply increased to 131.5% at the rolling ratio of 60%. In addition to the mechanical properties, electrical resistivity was also investigated; notably, this property was not significantly affected by the rolling process. Furthermore, the MWCNT dispersion and morphology were investigated by scanning electron microscopy. These findings offer a simple and effective method to fabricate conductive composites with excellent mechanical properties.

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