Macromol最新文献_第8页

Antimicrobial Activity of Composites-Based on Biopolymers 基于生物聚合物的复合材料的抗菌活性

Macromol Pub Date : 2022-06-30 DOI: 10.3390/macromol2030018

M. Bustamante-Torres, Belén Arcentales-Vera, Jocelyne Estrella-Nuñez, Heidi Yánez-Vega, E. Bucio

{"title":"Antimicrobial Activity of Composites-Based on Biopolymers","authors":"M. Bustamante-Torres, Belén Arcentales-Vera, Jocelyne Estrella-Nuñez, Heidi Yánez-Vega, E. Bucio","doi":"10.3390/macromol2030018","DOIUrl":"https://doi.org/10.3390/macromol2030018","url":null,"abstract":"Microorganisms have developed a resistance against some of the most conventional antibiotics. These microorganisms can be self-assembled, forming a microbial biofilm. A microbial biofilm formation is an inherent event on almost any surface, causing countless side effects on human health and the environment. Therefore, multiple scientific proposals have been developed based on renewable sources such as natural polymers. Natural polymers or biopolymers include cellulose, chitosan, starch, collagen, gelatin, hyaluronic acid, alginates, fibrin, and pectin, which are widely found in nature. The biopolymers have displayed many interesting properties, including biocompatibility and biodegradability. Nonetheless, these materials usually have no antimicrobial properties (except for the chitosan) by themselves. Therefore, antimicrobial agents have been incorporated into the natural polymeric matrix, providing an antimicrobial property to the biocomposite. Biocomposites consist of two different materials (one of natural origin) studied as biocompatible and biodegradable drug carriers of antimicrobial agents. In addition, due to the incorporation of antimicrobial agents, biocomposites can inhibit biofilm formation and bacteria proliferation on many surfaces. This review describes this using natural polymers as a platform of antimicrobial agents to form a biocomposite to eliminate or reduce biofilm formation on different surfaces.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"1146 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87923500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13

Partially Compacted Commingled PLA-Flax Biocomposites 部分压实混合pla -亚麻生物复合材料

Macromol Pub Date : 2022-06-22 DOI: 10.3390/macromol2030017

B. Lekube, C. Burgstaller

引用次数: 1

Poly(L-lactide) Epimerization and Chain Scission in the Presence of Organic Bases 有机碱存在下聚l -丙交酯的外映和链断裂

Macromol Pub Date : 2022-06-15 DOI: 10.3390/macromol2020016

J. Meimoun, Audrey Favrelle-Huret, J. Winter, P. Zinck

引用次数: 1

Influence of Surface Texture on Sealing Performance of PTFE Materials 表面织构对聚四氟乙烯材料密封性能的影响

Macromol Pub Date : 2022-06-08 DOI: 10.3390/macromol2020015

X. Ding, Jian Wu, Yonggang Wang, B. Cui, S. An, B. Su, Youshan Wang

{"title":"Influence of Surface Texture on Sealing Performance of PTFE Materials","authors":"X. Ding, Jian Wu, Yonggang Wang, B. Cui, S. An, B. Su, Youshan Wang","doi":"10.3390/macromol2020015","DOIUrl":"https://doi.org/10.3390/macromol2020015","url":null,"abstract":"Due to the hydrodynamic pressure effect, the bearing capacity of the oil film on the surface of a textured friction pair is greater than that of a smooth surface. In this paper, the effects of PTFE surface texture parameters (shape, depth, width, and area ratio) on the oil film bearing capacity and leakage of the sealing system under lubrication are studied using the FLURNT simulation. It is found in this present study that greater texture depths do not necessarily lead to better sealing performance. When the texture depth exceeds a certain level, a reverse flow occurs at the bottom of the texture, thereby weakening the hydrodynamic pressure effect. An optimal texture depth of 5–10 μm maximizes the oil film bearing capacity. Within a certain range, the oil film bearing capacity increases along with texture widths. In addition, leakage of the rectangular texture rises significantly with growing texture widths. Larger texture area ratios result in higher leakage, but the bearing capacity first rises and then falls with an increase in the area ratio, with a maximum value of 70–80%. Considering the influence of texture parameters on oil film bearing capacity and leakage, selecting the most appropriate texture parameters for surface texture treatment optimizes the performance of the sealing system. The findings of this paper provide a theoretical basis for improving the sealing performance of high-end aviation equipment using texture treatment, thereby enabling the application of surface texture technology to improve the tribological properties of materials.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82447131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Multiwalled Carbon Nanotube-Coated Poly-Methyl Methacrylate Dispersed Thermoplastic Polyurethane Composites for Pressure-Sensitive Applications 多壁碳纳米管包覆聚甲基丙烯酸甲酯分散热塑性聚氨酯复合材料的压敏应用

Macromol Pub Date : 2022-06-06 DOI: 10.3390/macromol2020014

Syed Muhammad Imran, Gwang-Myeong Go, M. Hussain, M. Al‐harthi

{"title":"Multiwalled Carbon Nanotube-Coated Poly-Methyl Methacrylate Dispersed Thermoplastic Polyurethane Composites for Pressure-Sensitive Applications","authors":"Syed Muhammad Imran, Gwang-Myeong Go, M. Hussain, M. Al‐harthi","doi":"10.3390/macromol2020014","DOIUrl":"https://doi.org/10.3390/macromol2020014","url":null,"abstract":"Thermoplastic polyurethane (TPU) is a widely used polymer for a variety of pressure sensing applications because of its softness and shape memory. This work reports the synthesis of novel TPU-based three-dimensional structured (3D) pressure-sensitive composites via the melt mixing method. Poly-methyl methacrylate (PMMA) microbeads of different sizes (5, 10, and 20 µm) were first coated with multi-walled carbon nanotubes (MWCNT) and then incorporated into the TPU matrix for achieving an early electro conductive percolation threshold compared to without PMMA beads. The addition of MWCNT coated PMMA beads reduced the TPU insulated areas by creating a 3D conductive network that finally reflected the early percolation threshold during external pressure. Raman microscopy and XRD results confirmed the MWCNT coated nicely on the surface of PMMA beads. The pressure sensitivity results also confirmed the decrease in resistance of the composites with the increase in the applied external pressure. Composites with 10 µm PMMA bead size showed the most linear responses to the decrease in resistance with increasing pressure and showed a higher strain gauge factor value (3.15) as compared to other composites, which had values of 2.78 and 2.42 for 20 and 5 µm, respectively. Microstructure analysis of the composites by SEM, capacitance, permeability, and thermal conductivity measurements was also investigated to support the above evidence. The results support the suitability of this novel composite as a potential candidate for pressure sensing applications.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84531556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Polymerization Initiated by Graphite Intercalation Compounds Revisited: One-Pot Synthesis of Amphiphilic Pentablock Copolymers 石墨插层化合物引发的聚合:一锅法合成两亲五嵌段共聚物

Macromol Pub Date : 2022-05-14 DOI: 10.3390/macromol2020012

N. Vladimirov, I. Gitsov

引用次数: 1

Influence of Ethylene-1-Alkene Copolymers Microstructure on Thermo-Rheological Behavior of Model Blends for Enhanced Recycling 乙烯-1-烯烃共聚物微观结构对模型共混物热流变行为的影响

Macromol Pub Date : 2022-04-24 DOI: 10.3390/macromol2020011

G. Galgali, S. Kaliappan, Tej Pandit

{"title":"Influence of Ethylene-1-Alkene Copolymers Microstructure on Thermo-Rheological Behavior of Model Blends for Enhanced Recycling","authors":"G. Galgali, S. Kaliappan, Tej Pandit","doi":"10.3390/macromol2020011","DOIUrl":"https://doi.org/10.3390/macromol2020011","url":null,"abstract":"Polyethylenes (PE) are the most commonly occurring ingredients for post-consumer recyclates (PCR). The structure–property relationships of different types of model PE-based blends are established using multiple thermo-rheological analyses. Although considered “simple”, the complex behavior of model PE-based blends is experimentally demonstrated for the first time for metallocene-catalyzed, linear, low-density polyethylenes (mLLDPE) with different microstructures that are commonly encountered in PCR. During non-isothermal crystallization, the microstructure of mLLDPE predominantly influences the interaction between mLLDPE and LDPE. Based on the mLLDPE microstructure, the molten LDPE phase acts either as a nucleating agent or as a crystallization rate promoting agent. Both rheological and thermal analyses show that higher activation energy is required for the reptation or movement of polymer chains in a highly branched microstructure with long chain branching (LCB) compared to a linear microstructure with short chain branching (SCB). The quasi-melt response, as measured by thermal analysis under non-isothermal conditions, is distinctly different and sensitive to both the SCB and LCB present in the LLDPE/LDPE blends.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78662122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Toughened Bio-Polyamide 11 for Impact-Resistant Intraply Basalt/Flax Hybrid Composites 用于抗冲击的玄武岩/亚麻混杂复合材料的增韧生物聚酰胺11

Macromol Pub Date : 2022-04-06 DOI: 10.3390/macromol2020010

C. Sergi, Libera Vitiello, P. Russo, J. Tirillò, F. Sarasini

{"title":"Toughened Bio-Polyamide 11 for Impact-Resistant Intraply Basalt/Flax Hybrid Composites","authors":"C. Sergi, Libera Vitiello, P. Russo, J. Tirillò, F. Sarasini","doi":"10.3390/macromol2020010","DOIUrl":"https://doi.org/10.3390/macromol2020010","url":null,"abstract":"The automotive sector covers almost 40% of polyamide (PA) total demand. A suitable solution to improve the sustainability of this sector is the exploitation of PA matrices sourced from renewable origins, such as PA11, and their reinforcement with natural fibers such as vegetable flax and mineral basalt. A preliminary study on the quasi-static properties of PA11-based composites reinforced with an intraply flax/basalt hybrid fabric demonstrated their feasibility for semi-structural purposes in the transportation field, but their application needs to be validated against dynamic loading. In this regard, this work investigated the low-velocity impact performance of PA11 flax/basalt hybrid composites (10 J, 20 J and 30 J) as a function of temperature (room temperature and +80 °C) and plasticizer addition (butyl-benzene-sulfonamide). The results proved that plasticized PA11 is endowed with a lower glass transition temperature (~15 °C, from DMA) and melting temperature (~10 °C, from DSC), which simplifies manufacturing and processing, but also possesses a higher toughness which delays penetration phenomena and reduces permanent indentation at room temperature between 20.5% and 42.8% depending on impact energy. The occurrence of matrix plasticization at +80 °C caused a more flexible and tougher response from the laminates with a decrease in linear stiffness and a delay in penetration phenomena which made the plasticizer effect less prominent.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83389344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Long-Chain Hydrosilanes Mediated Phase Transfer of Aqueous Metal Nanoparticles 长链氢硅烷介导的水相转移金属纳米颗粒

Macromol Pub Date : 2022-03-29 DOI: 10.3390/macromol2020009

Elijah Cook, Qiaxian R. Johnson, Gurjeet Longia, Gurpreet Longia, B. Chauhan

引用次数: 0

Development of Water-Soluble Type I Photoinitiators for Hydrogel Synthesis 水凝胶合成中水溶性I型光引发剂的研究进展

Macromol Pub Date : 2022-03-21 DOI: 10.3390/macromol2010008

Bérengère Aubry, F. Dumur, M. Lansalot, E. Bourgeat‐Lami, Emmanuel Lacôte, J. Lalevée

引用次数: 1