Effect of crosslink on tribological performance of polyurethane bearing material

Jiang, Shaoli; Yuan, Chengqing; Guo, Zhiwei; Bai, Xiuqin

doi:10.1016/j.triboint.2019.03.064

Cited by 26 publications

(11 citation statements)

References 28 publications

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“…Several oxidation mechanisms for TPU following the type of energy input have been proposed including the conversion of the bis phenyl methylene groups into allenes groups with conjugated double bonds [ 33 ]. Free radicals generated by radiolysis with oxygen during irradiation could initiate these mechanisms [ 23 ] and the accumulation of conjugated double bonds from the formation of these chromophore structures is responsible for the color change [ 34 ]. Surface properties investigation via infrared spectroscopy indicated changes in surface chemistry after sterilization.…”

Section: Discussionmentioning

confidence: 99%

“…Murray et al made the presumption that the effect of crosslinking in TPU are not recognizable with doses lower than 200 kGy. It has also been documented that commercial TPUs exhibit a resistance to irradiation up until a certain threshold of multiple hundreds of kGy [ 22 , 23 , 34 ]. By “only” undergoing a dose of 40 kGy, the elastomeric properties of TPU remained intact and compliant with our application.…”

Section: Discussionmentioning

confidence: 99%

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Evaluation of a Medical Grade Thermoplastic Polyurethane for the Manufacture of an Implantable Medical Device: The Impact of FDM 3D-Printing and Gamma Sterilization

et al. 2023

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Three-dimensional printing (3DP) of thermoplastic polyurethane (TPU) is gaining interest in the medical industry thanks to the combination of tunable properties that TPU exhibits and the possibilities that 3DP processes offer concerning precision, time, and cost of fabrication. We investigated the implementation of a medical grade TPU by fused deposition modelling (FDM) for the manufacturing of an implantable medical device from the raw pellets to the gamma (γ) sterilized 3DP constructs. To the authors’ knowledge, there is no such guide/study implicating TPU, FDM 3D-printing and gamma sterilization. Thermal properties analyzed by differential scanning calorimetry (DSC) and molecular weights measured by size exclusion chromatography (SEC) were used as monitoring indicators through the fabrication process. After gamma sterilization, surface chemistry was assessed by water contact angle (WCA) measurement and infrared spectroscopy (ATR-FTIR). Mechanical properties were investigated by tensile testing. Biocompatibility was assessed by means of cytotoxicity (ISO 10993-5) and hemocompatibility assays (ISO 10993-4). Results showed that TPU underwent degradation through the fabrication process as both the number-averaged (Mn) and weight-averaged (Mw) molecular weights decreased (7% Mn loss, 30% Mw loss, p < 0.05). After gamma sterilization, Mw increased by 8% (p < 0.05) indicating that crosslinking may have occurred. However, tensile properties were not impacted by irradiation. Cytotoxicity (ISO 10993-5) and hemocompatibility (ISO 10993-4) assessments after sterilization showed vitality of cells (132% ± 3%, p < 0.05) and no red blood cell lysis. We concluded that gamma sterilization does not highly impact TPU regarding our application. Our study demonstrates the processability of TPU by FDM followed by gamma sterilization and can be used as a guide for the preliminary evaluation of a polymeric raw material in the manufacturing of a blood contacting implantable medical device.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Evaluation of a Medical Grade Thermoplastic Polyurethane for the Manufacture of an Implantable Medical Device: The Impact of FDM 3D-Printing and Gamma Sterilization

et al. 2023

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“…Therefore, both the synthesis method and the nature of the reagents significantly affect the physical, chemical, mechanical, and structural properties of the NIPU, and these are defined by the application end-use. Thus, for instance, the length of the monomeric segments forming the chains or their nature or the crosslinking degree of a polyurethane is directly linked to its elasticity/rigidity, its foaming capacity or its thermal behavior, which divides polyurethanes into thermoplastics (TPU) and thermosets, depending on these factors [ 36 , 37 , 38 , 39 ].…”

Section: Introductionmentioning

confidence: 99%

Tailor-Made Bio-Based Non-Isocyanate Polyurethanes (NIPUs)

et al. 2023

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Non-isocyanate polyurethanes (NIPUs) based on biobased polyamines and polycarbonates are a sustainable alternative to conventional polyurethanes (PU). This article discloses a novel method to control the crosslinking density of fully biobased isocyanate-free polyurethanes, synthesized from triglycerides carbonated previously in scCO2 and different diamines, such as ethylenediamine (EDA), hexamethylenediamine (HMDA) and PriamineTM-1075 (derived from a dimerized fatty acid). As capping substances, water or bioalcohols are used in such a way that the crosslinking density can be adjusted to suit the requirements of the intended application. An optimization of the NIPU synthesis procedure is firstly carried out, establishing the polymerization kinetics and proposing optimal conditions set for the synthesis of the NIPUs. Then, the influence of the partial blocking of the active polymerization sites of the carbonated soybean oil (CSBO), using monofunctional amines, on the physical properties of the NIPUS is explored. Finally, the synthesis of fully biobased NIPUs with a targeted crosslinking density is achieved using hybrid NIPUs, employing partially carbonated oil and H2O or ethanol as blockers to achieve the desired physical properties in a very precise manner.

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“…Moreover, it is easy to be processed into key parts using the heat injection molding method due to its low melting temperature, which is between 190 • C and 200 • C [6]. Therefore, it is widely used in the manufacture of water-lubricated polymer bearings in the marine field [7,8]. With the development of the economy, ships are becoming larger, leading to the diameters of the ship's propulsion shafts becoming bigger and bigger, especially for big ships traveling over seawater.…”

Section: Introductionmentioning

confidence: 99%

Reinforcement of Frictional Vibration Noise Reduction Properties of a Polymer Material by PTFE Particles

Dong

2022

Materials

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The insufficient lubrication of the contact interface between moving parts can easily induce severe friction vibration and noise under extreme working conditions, which will threaten the service life and reliability of polymer moving components, including water-lubricated stern tube polymer bearings. Thermoplastic polyurethane (TPU) modified by polytetrafluoroethylene (PTFE) particles was developed. The effects of PTFE on the wear and vibration behaviors of modified TPU sliding against the ZCuSn10Zn2 ring-plates were investigated. The coefficients of friction (COFs), wear mass losses, wear morphologies, frictional vibration, and noise were analyzed synthetically. The results showed that a suitable mass content of PTFE reduced the COFs and wear mass losses of the TPU composites by more than 50% and 40%, respectively, while presenting an excellent friction reduction. The lower COFs of modified TPU showed a small fluctuation amplitude and eliminated vibration waveforms at high vibrational frequencies, which was useful for reducing frictional vibration and noise. The knowledge gained in this study is useful for a better understanding of the wear behaviors of polymer composites, as well as for the design a new polymer material with good self-lubricating and frictional vibration and noise reduction properties.

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Effect of crosslink on tribological performance of polyurethane bearing material

Cited by 26 publications

References 28 publications

Evaluation of a Medical Grade Thermoplastic Polyurethane for the Manufacture of an Implantable Medical Device: The Impact of FDM 3D-Printing and Gamma Sterilization

Evaluation of a Medical Grade Thermoplastic Polyurethane for the Manufacture of an Implantable Medical Device: The Impact of FDM 3D-Printing and Gamma Sterilization

Tailor-Made Bio-Based Non-Isocyanate Polyurethanes (NIPUs)

Reinforcement of Frictional Vibration Noise Reduction Properties of a Polymer Material by PTFE Particles

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