The Effect of Mixed Chain Extender on the Hydrogen Bonding, Thermal and Mechanical Properties of TPUs

2020 ◽  
Vol 1001 ◽  
pp. 16-21
Author(s):  
Ju Jie Sun ◽  
Hai Rui Wang ◽  
Lan Cao ◽  
Tridib K. Sinha

Chain extender plays a significant role in enhancing the final mechanical properties of thermoplastic polyurethane (TPUs) derived from polytetra methylene etherglycol (PTMG) and 4,4-diphenylmethane diisocyanate (MDI). In this research we focused on the effect that mixed chain extender of ethylene glycol (EG) and 1,4-butanediol (BDO) used has on the phase behavior and morphology of high hard block content TPUs. DSC, FTIR, and mechanical testing were mainly used to characterize the morphology and properties of the TPUs materials. Through this work we were able to show that mixed ratio of different chain extenders had dramatic effects on the properties of the TPUs. After mixing EG and BDO, the degree of hydrogen bonding, melting temperature, tensile strength, tear strength, and hardness of TPUs are all reduced, the glass transition temperature is increased. when the mixing ratio is 1: 1 , the elongation at break is increased to 672% . However, when the mixing ratio is n (EG): n (BDO) = 1: 2, the tensile strength is increased to 29.2 MPa, and the elongation at break is reduced to 353%.

2013 ◽  
Vol 772 ◽  
pp. 34-37
Author(s):  
Hao Tang ◽  
Hai Tian Jiang ◽  
Bin Guo ◽  
Pan Xin Li

Corn starch was irradiated by 60Coγ ray, and then the thermoplastic starch plastic (TPS) was prepared by adding glycerol. Microstructure, thermal and mechanical properties of the corn starch and starch plastic were studied in details by FTIR, DSC and SEM. Results showed that the starch macromolecular structure was damaged by irradiation, and with increased irradiation time, the temperature of melt endothermic peak and tensile strength decreased, elongation at break increases for starch plastic, the thermoplastic property of starch was enhanced obviously.


2005 ◽  
Vol 21 (3) ◽  
pp. 219-230 ◽  
Author(s):  
Arup Choudhury ◽  
Mandira Mukherjee ◽  
Basudam Adhikari

The present investigation deals with the viability of the use of recycled milk pouch material, which is a 50:50 mixture of LDPE and LLDPE, and the scope for improvement of its properties by combining it with virgin LDPE-LLDPE (50/50). Melt flow index (MFI), rheological properties, thermal and mechanical properties of the pure materials and their formulated blends containing recycled milk pouches were studied. The properties of the recycled materials were not as satisfactory as those of the corresponding virgin materials. But a significant improvement in viscosity, crystallinity, tensile strength and elongation at break of the recycled LDPE-LLDPE material was achieved by blending it with the corresponding virgin LDPE-LLDPE blend.


Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 308 ◽  
Author(s):  
Maria Cristina Righetti ◽  
Patrizia Cinelli ◽  
Norma Mallegni ◽  
Andreas Stäbler ◽  
Andrea Lazzeri

The thermal and mechanical properties of biocomposites of poly(3-hydroxybutyrate-co- 3-hydroxyvalerate) (PHBV) containing 5 wt % of valerate units, with 20 wt % of potato pulp powder were investigated in order (i) to obtain information on possible miscibility/compatibility between the biopolymers and the potato pulp, and (ii) to quantify how the addition of this filler modifies the properties of the polymeric material. The potato pulp powder utilized is a residue of processing for the production and extraction of starch. The final aim of this study is the preparation of PHBV based materials with reduced cost, thanks to biomass valorization, in agreement with the circular economy policy, as result of the incorporation of agricultural organic waste. The results showed that the potato pulp powder does not act as reinforcement, but rather as filler for the PHBV polymeric matrix. A moderate loss in mechanical properties is detected (decrease in elastic modulus, tensile strength and elongation at break), which regardless still meets the technical requirements indicated for rigid packaging production. In order to improve the mechanical response of the PHBV/potato pulp powder biocomposites, surface treatment of the potato pulp powder with bio-based and petroleum-based waxes was investigated. Good enhancement of the mechanical properties was achieved with the natural carnauba and bee waxes.


2012 ◽  
Vol 602-604 ◽  
pp. 690-695
Author(s):  
Hua Dong Wang ◽  
Rui Wang ◽  
Mao Fang Huang ◽  
Qi Yang

Thermoplastic vulcanizates (TPVs) based on epoxidized natural rubber (ENR) and polypropylene (PP) were prepared in an internal mixer at 180°C. The effects of curing systems (i.e., sulfur and peroxide) on morphological, rheological, thermal and mechanical properties were studied. It is found that the sulfur cured TPVs show higher tensile strength, tear strength and elongation at break than those cured with the DCP systems. The rheological analysis indicates that TPVs cured with DCP system show lower apparent shear viscosity than those with sulfur system. SEM studies show that TPVs vulcanized with DCP system exhibit smaller and finely dispersed rubber domains, which provides it higher thermal stability than sulfur cured TPVs.


RSC Advances ◽  
2014 ◽  
Vol 4 (46) ◽  
pp. 24095-24102 ◽  
Author(s):  
Chao Deng ◽  
Yulin Cui ◽  
Tingting Zhao ◽  
Mei Tan ◽  
He Huang ◽  
...  

Polyurethane–urea supramolecular hydrogel with excellent mechanical and processible properties is developed. The mechanical properties including shear modulus, elongation at break, tensile strength and compression stress can be adjusted by altering the diisocyanate content.


2012 ◽  
Vol 200 ◽  
pp. 278-281 ◽  
Author(s):  
Yi Chen ◽  
Wei Jian Xu ◽  
Guang Sheng Zeng ◽  
Xiao Hong Zeng ◽  
Wen Yong Liu ◽  
...  

Polyamide 6/Poly(lactic acid) (PA6/PLA) blends introduce the degradability of PLA to high performance PA6, but the bad toughness of both PA6 and PLA limits the application of blends. Aiming at this deficiency, thermoplastic polyurethane (TPU) was used as an additive for modifying the toughness of PA6/PLA blends. PA6/PLA/TPU blends at various compositions were prepared by melt blending, the effects of blend compositions on the morphology, thermal and mechanical properties of blends were investigated. The results showed that the addition of TPU improves the compatibilization between PA6 and PLA and makes the blends show more obvious plastic fracture behavior than PA6/PLA.When the content of PLA in PA6/PLA increases, the impact and tensile strength of blends decrease slightly with the intense decrease of the elongation at break, adding TPU into PA6/PLA blends strengthens the toughness of blends, but the tensile strength of blends decreases. Moreover, the crystallinity of PA6 /PLA blend is hampered by TPU.


Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 356
Author(s):  
Marcin Włoch ◽  
Paulina Landowska

Bio-based fillers for the polymer composites are still interesting from the scientific and industrial point of view, due to their low cost and renewable nature. In this work partially green composites were obtained by the mixing of thermoplastic poly(ester-urethane) with the unmodified and modified (by acetylation) grinded buckwheat husks. Obtained biocomposites were characterized in the terms of their chemical structure (FTIR), microstructure (SEM), thermal stability (TGA), thermomechanical properties (DMTA), and selected mechanical properties. The results showed that introduction of grinded buckwheat husks (even if the amount is 60 wt%) permit retaining high values of tensile strength (around 8–10 MPa), but the increasing amount of applied filler is connected with the decreasing of elongation at break. It can result from good interaction between the polymer matrix and the bio-based filler (confirmed by high values of polymer matrix-filler interaction parameter determined from Pukánszky’s model for the tensile strength of composites). The applied chemical treatment results in changing of mechanical properties of filler and composites. Obtained results confirmed the possibility of using powdered buckwheat husks as filler for thermoplastic polyurethane.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1502
Author(s):  
Eliezer Velásquez ◽  
Sebastián Espinoza ◽  
Ximena Valenzuela ◽  
Luan Garrido ◽  
María José Galotto ◽  
...  

The deterioration of the physical–mechanical properties and loss of the chemical safety of plastics after consumption are topics of concern for food packaging applications. Incorporating nanoclays is an alternative to improve the performance of recycled plastics. However, properties and overall migration from polymer/clay nanocomposites to food require to be evaluated case-by-case. This work aimed to investigate the effect of organic modifier types of clays on the structural, thermal and mechanical properties and the overall migration of nanocomposites based on 50/50 virgin and recycled post-consumer polypropylene blend (VPP/RPP) and organoclays for food packaging applications. The clay with the most hydrophobic organic modifier caused higher thermal stability of the nanocomposites and greater intercalation of polypropylene between clay mineral layers but increased the overall migration to a fatty food simulant. This migration value was higher from the 50/50 VPP/RPP film than from VPP. Nonetheless, clays reduced the migration and even more when the clay had greater hydrophilicity because of lower interactions between the nanocomposite and the fatty simulant. Conversely, nanocomposites and VPP/RPP control films exhibited low migration values in the acid and non-acid food simulants. Regarding tensile parameters, elongation at break values of PP film significantly increased with RPP addition, but the incorporation of organoclays reduced its ductility to values closer to the VPP.


2021 ◽  
Vol 11 (12) ◽  
pp. 5317
Author(s):  
Rafał Malinowski ◽  
Aneta Raszkowska-Kaczor ◽  
Krzysztof Moraczewski ◽  
Wojciech Głuszewski ◽  
Volodymyr Krasinskyi ◽  
...  

The need for the development of new biodegradable materials and modification of the properties the current ones possess has essentially increased in recent years. The aim of this study was the comparison of changes occurring in poly(ε-caprolactone) (PCL) due to its modification by high-energy electron beam derived from a linear electron accelerator, as well as the addition of natural fibers in the form of cut hemp fibers. Changes to the fibers structure in the obtained composites and the geometrical surface structure of sample fractures with the use of scanning electron microscopy were investigated. Moreover, the mechanical properties were examined, including tensile strength, elongation at break, flexural modulus and impact strength of the modified PCL. It was found that PCL, modified with hemp fibers and/or electron radiation, exhibited enhanced flexural modulus but the elongation at break and impact strength decreased. Depending on the electron radiation dose and the hemp fibers content, tensile strength decreased or increased. It was also found that hemp fibers caused greater changes to the mechanical properties of PCL than electron radiation. The prepared composites exhibited uniform distribution of the dispersed phase in the polymer matrix and adequate adhesion at the interface between the two components.


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