China
Africa
Explore chapters and articles related to this topic
Determination of the composition of imported recycled polyamide/polyethylene blends by differential scanning calorimetry
Published in Binoy K. Saikia, Advances in Applied Chemistry and Industrial Catalysis, 2022
KaiDong Lin, Chao Zhang, FengPing Ni, Chuan Luo
Polyamide is usually called nylon, which is mainly used in the production of films, fibers, engineering plastics, etc., and is the largest consumption of the five engineering plastics in the world so far. According to the statistical data of recycled particles imported from several major ports in China in recent years, some recycled plastic particles from composite film materials may contain polyethylene and polyamide at the same time. When those two different types of polymers are blended, they may be reconstituted particles of many different batches of film materials, the composition of recycled particles may be inconsistent, which will affect the subsequent use.
Bio-based Polyamides
Published in Abdullah Al-Mamun, Jonathan Y. Chen, Industrial Applications of Biopolymers and their Environmental Impact, 2020
Polyamides are generally characterized by high strength and stiffness properties, and excellent heat deformation resistance. The amide group (CO–NH, Fig. 3.4) is characteristic of all polyamides, and is decisive for their behavior. There are four monomer groups that are used to manufacture polyamides: dicarbonic acids, diamines, lactams, and amino acids. Furthermore, as was also the case for petro-based polyamides, the macroscopic properties of bio-based polyamides are dependent on the monomers and their number of C-atoms.
Blown Film Technology
Published in Nicholas P. Cheremisinoff, Elastomer Technology Handbook, 2020
Nylons, or more correctly, polyamides, are engineering resins, some grades of which can be extruded as blown film. Polyamides are addition polymers made from a dibasic acid and a diamine; the resulting polymer contains an amide group as part of each repeat unit. This polar group has some bulk which stiffens the backbone slightly, but more importantly, it offers sites for hydrogen bonding intra- and interchain. Hydrogen bonding gives the polymer the toughness, and its barrier properties make it useful as a blown film. The fact that the segmental motion is reduced by hydrogen bonds means that the polymer toughness and barrier characteristics are very subject to the moisture content of the material; moisture interrupts the hydrogen bonding.
Design and analysis of a polyamide – steel hybrid A-pillar for increased vehicle roof structural integrity in rollover accident scenarios
Published in International Journal of Crashworthiness, 2021
Rindai Mahoso, Sagar Singh Parihar
As can be shown from Table 4.1, polyamide is the clear choice as it ticks the boxes for the best stiffness and strength performance through the relatively high elastic modulus and strength values. It has also been shown to have lower cost on the market and higher availability. Polyamide also possesses the amide group in its polymer structure which aids in its direct adhesion to metals, through the breaking of the carbon-oxygen double bond and the subsequent diffusion of oxygen into the metal and formation of carbon-metal bond [14]. This effect is best exhibited by polyamide 6/6 as it has a higher amide group presence in its polymer backbone which then poses as a significant advantage over the other materials especially in line with direct adhesion. Polyamide has also been shown to produce good direct adhesion to steel components in the range of 40 MPa in perfect conditions [7]. The major drawback with polyamide however is its sensitivity to moisture hence care during manufacture and operation is crucial.
The effect of O2 plasma treatment and PA 6 coating on digital ink-jet printing of PET non-woven fabric
Published in The Journal of The Textile Institute, 2020
Md Ali Hossain, Weiguo Chen, Jinhuan Zheng, Ya Zhang, Chenglong Wang, Shulan Jin, Hao Wu
Polyamide is the amide (-NH-CO-) containing group in their main chain, which is generally known as nylon. Polyamide 6 is widely used in the industry. PA 6 coating with a solution containing waste PA 6 filament is environmentally friendly because of the use of waste materials. PA 6 chemical structure shows it has a low number of hydrocarbon groups and has carbonyl and -NH group, which gives this polymer a hydrophilic property. During the dissolving process of PA 6 filament, the solution was heated to break the hydrogen bond of methanol. Then calcium chloride and methanol complex molecules come close to PA 6 owing to the intermolecular interaction between O-H and C = O groups. Eventually, CaCl2-PA 6 complex and free methanol are formed (Hattori, Saito, Okajima, & Kamide, 1995; McKeen, 2013).
Immobilized carbon-doped TiO2 in polyamide fibers for the degradation of methylene blue
Published in Journal of Asian Ceramic Societies, 2019
Syasya Nazifa Binti Saiful Amran, Viona Wongso, Nur Syakinah Abdul Halim, Muhammad Khalid Husni, Nonni Soraya Sambudi, Muhammad Dzul Hakim Wirzal
Polyamide is a widely used polymer in the textile industry due to its excellent properties such as high impact resilience, toughness, high flexibility, and excellent resistance to abrasion, organic solvents and water [26]. The immobilization of TiO2 in polyamide affects its properties and functions, including its photocatalytic performance, surface area, and adsorption. This technique also eliminates the need to separate the catalyst particles from treated wastewater and allows contaminated water to be treated constantly. A previous study on immobilizing carbon-doped TiO2 in polyvinyl pyrrolidone (PVP) fibers was conducted by Mondal et al. [27] to degrade naphthalene; an improvement in degradation was shown when carbon-doped TiO2 was immobilized in PVP fibers. In this study, polyamide was used as polymeric fiber support for carbon-doped TiO2. A previous study by Zhang et al. [28] utilizing polyamide fibers to immobilize Fe-doped TiO2 showed the improvement of methylene blue degradation under sunlight and UV irradiation. Additionally, polyamide fibers provide composites with mechanical strength, such as improved breaking force and elongation [28].