scholarly journals Alendronate Release from UHMWPE-Based Biomaterials in Relation to Particle Size of the GUR Powder for Manufacturing

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1832
Author(s):  
Michael Seidenstuecker ◽  
Julia Weber ◽  
Sergio H. Latorre ◽  
Brigitte Straub ◽  
Ulrich Matthes ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
Strong Influence ◽  
Molar Mass ◽  
Negative Influence ◽  
Release Behavior ◽  
Elongation At Break ◽  
Continuous Release ◽  
The Subject ◽  
Ultra High Molecular Weight

Ultra-high molecular weight polyethylene (UHMWPE) is widely used in endoprosthetics and has been the subject of countless studies. This project investigates the dependence of alendronate (AL) release on the molecular weight of the UHMWPE used (GUR1020 and GUR1050). A 0.5 wt% AL was added to the UHMWPE during the production of the moldings. In addition to the 14-day release tests, biocompatibility tests such as live dead assay, cell proliferation assay (WST) and Lactate dehydrogenase test (LDH) with MG-63 cells as well as a tensile test according to DIN EN ISO 527 were carried out. The released AL concentration was determined by HPLC. A continuous release of the AL was observed over the entire period of 2 weeks. In addition, a correlation between molar mass and AL release was demonstrated. The GUR1020 showed a release four times higher than the GUR1050. Both materials have no negative influence on the proliferation of MG-63 cells. This was also confirmed in the live/dead assay by the increase in cell count. No cytotoxicity was detected in the LDH test. The addition of 0.5 wt% AL increased the elongation at break for GUR1020 by 23% and for GUR1050 by 49%. It was demonstrated that the choice of UHMWPE has an influence on the release of AL. The particle size in particular has a strong influence on the release behavior.

Effects of electron beam irradiation on structure and properties of ultra-high molecular weight polyethylene fiber

2017 ◽  
Vol 47 (6) ◽  
pp. 1357-1377 ◽  
Author(s):  
Dongliang Dai ◽  
Meiwu Shi
Keyword(s):  
Molecular Weight ◽  
Electron Beam ◽  
High Molecular Weight ◽  
Electron Beam Irradiation ◽  
Breaking Strength ◽  
Beam Irradiation ◽  
Elongation At Break ◽  
Gel Content ◽  
Ultra High Molecular Weight ◽  
Polyethylene Fibers

This study introduced trimethylolpropane trimethacrylate into ultra-high molecular weight polyethylene fibers through supercritical CO2 pretreatment before the fibers were irradiated under an electron beam. Significant differences, emerging in the ultra-high molecular weight polyethylene fibers’ gel content, mechanical properties, and creep property according to their different irradiation doses, were studied through one-way analysis of variance. Regression equations were established between the irradiation dose and the gel content, breaking strength, elongation at break, and creep rate by regression analysis. A reasonable irradiation dosage range was determined after a verification experiment and the impact trends were analyzed; additionally, the sensitized irradiation crosslinking mechanism of ultra-high molecular weight polyethylene fibers was preliminarily examined. Then the surface morphology, chemical structures, thermal properties, and crystal properties of treated ultra-high molecular weight polyethylene fibers were measured. The results showed that as the irradiation dose increased, the gel content first rose and then declined; the breaking strength decreased continuously; the elongation at break increased at first and then decreased; and the creep rate originally fell and then rose before finally declining slowly. Electron beam irradiation had a significant etching effect on the fibers’ surface, and both the melting point and crystallinity decreased slightly.

scholarly journals Ultra-high molecular weight elastomeric polyethylene using an electronically and sterically enhanced nickel catalyst

2017 ◽  
Vol 8 (41) ◽  
pp. 6416-6430 ◽  
Author(s):  
Qaiser Mahmood ◽  
Yanning Zeng ◽  
Erlin Yue ◽  
Gregory A. Solan ◽  
Tongling Liang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Tensile Strength ◽  
High Molecular Weight ◽  
Nickel Catalyst ◽  
High Tensile Strength ◽  
Elongation At Break ◽  
Highly Active ◽  
High Elongation ◽  
Ultra High Molecular Weight ◽  
Shape Fixity

Highly active para-t-Bu-containing 1,2-bis(imino)acenaphthene-Ni(ii) catalysts are disclosed which afford hyper-branched PEs with Mw's up to 3.1 × 106 g mol−1; high tensile strength, excellent shape fixity as well as high elongation at break are a feature.

scholarly journals Particle morphology, structure and properties of nascent ultra-high molecular weight polyethylene

2020 ◽  
Vol 7 (8) ◽  
pp. 200663
Author(s):  
Wenyang Zhang ◽  
Zhengwen Wu ◽  
Hanjun Mao ◽  
Xinwei Wang ◽  
Jianlong Li ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
High Molecular Weight ◽  
Liquid Paraffin ◽  
Particle Morphology ◽  
Particle Growth ◽  
Structure And Properties ◽  
Uhmwpe Particle ◽  
Ultra High Molecular Weight ◽  
Polymerization Method

The effects of particle morphology on the structure and swelling/dissolution and rheological properties of nascent ultra-high molecular weight polyethylene (UHMWPE) in liquid paraffin (LP) were elaborately explored in this article. Nascent UHMWPE with different particle morphologies was prepared via pre-polymerization technique and direct polymerization. The melting temperature and crystallinity of UHMWPE resins with different particle morphologies were compared, and a schematic diagram was proposed to illustrate the mechanism of UHMWPE particle growth synthesized by pre-polymerization method and direct polymerization. The polymer globules in the nascent UHMWPE prepared by using pre-polymerization technique are densely packed and a positive correlation between the particle size and the viscosity-averaged molecular weight can be observed. The split phenomenon of particles and the fluctuation in the viscosity of UHMWPE/LP system prepared by direct polymerization can be observed at a low heating rate and there is no correlation between particle size and viscosity-averaged molecular weight.

Polymer Composite Materials Based on Ultra High Molecular Weight Polyethylene Matrix Filled by Alumina Powders

2014 ◽  
Vol 1040 ◽  
pp. 124-129 ◽  
Author(s):  
O.V. Kovalevskaia ◽  
Y.I. Gordeev ◽  
Arthur K. Abkaryan
Keyword(s):  
Molecular Weight ◽  
Experimental Investigation ◽  
Particle Size ◽  
Composite Materials ◽  
High Molecular Weight ◽  
Polymer Composite ◽  
Polymer Composite Materials ◽  
Polyethylene Matrix ◽  
Microstructure And Properties ◽  
Ultra High Molecular Weight

The paper presents the results of experimental investigation of formation microstructure and properties of ultra high molecular weight polyethylene (UHMW-PE), modified by ceramics А12О3 particles by different particle size and method of obtaining.

scholarly journals Reinforcement of Styrene Butadiene Rubber Employing Poly(isobornyl methacrylate) (PIBOMA) as High Tg Thermoplastic Polymer

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1626
Author(s):  
Abdullah Gunaydin ◽  
Clément Mugemana ◽  
Patrick Grysan ◽  
Carlos Eloy Federico ◽  
Reiner Dieden ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Molar Mass ◽  
Rubber Matrix ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Linear Polymers ◽  
Elongation At Break ◽  
Vulcanized Rubber ◽  
Rubber Compounds ◽  
Styrene Butadiene

A set of poly(isobornyl methacrylate)s (PIBOMA) having molar mass in the range of 26,000–283,000 g mol−1 was prepared either via RAFT process or using free radical polymerization. These linear polymers demonstrated high glass transition temperatures (Tg up to 201 °C) and thermal stability (Tonset up to 230 °C). They were further applied as reinforcing agents in the preparation of the vulcanized rubber compositions based on poly(styrene butadiene rubber) (SBR). The influence of the PIBOMA content and molar mass on the cure characteristics, rheological and mechanical properties of rubber compounds were studied in detail. Moving die rheometry revealed that all rubber compounds filled with PIBOMA demonstrated higher torque increase values ΔS in comparison with rubber compositions without filler, independent of PIBOMA content or molar mass, thus confirming its reinforcing effect. Reinforcement via PIBOMA addition was also observed for vulcanized rubbers in the viscoelastic region and the rubbery plateau, i.e. from −20 to 180 °C, by dynamic mechanical thermal analysis. Notably, while at temperatures above ~125 °C, ultra-high-molecular-weight polyethylene (UHMWPE) rapidly loses its ability to provide reinforcement due to softening/melting, all PIBOMA resins maintained their ability to reinforce rubber matrix up to 180 °C. For rubber compositions containing 20 phr of PIBOMA, both tensile strength and elongation at break decreased with increasing PIBOMA molecular weight. In summary, PIBOMA, with its outstanding high Tg among known poly(methacrylates), may be used in the preparation of advanced high-stiffness rubber compositions, where it provides reinforcement above 120 °C and gives properties appropriate for a range of applications.

scholarly journals Conventional Ultra-high Molecular Weight Polyethylene versus Highly Cross-linked Polyethylene from Semi-constrained, Fixed-bearing Total Ankle Arthroplasty Systems

2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0010
Author(s):  
Oliver Schipper ◽  
Steven Haddad ◽  
Spencer Fullam ◽  
Robin Pourzal ◽  
Markus Wimmer
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
Wear Rate ◽  
High Molecular Weight ◽  
Particle Shape ◽  
Total Ankle Arthroplasty ◽  
Fixed Bearing ◽  
Ankle Arthroplasty ◽  
The Mean ◽  
Ultra High Molecular Weight

Category: Ankle Arthritis Introduction/Purpose: The aim of this study was to compare the polyethylene wear rate, particle size, and particle shape of primary semi-constrained, fixed-bearing, bone-sparing total ankle arthroplasty using conventional ultra-high molecular weight polyethylene (CPE) versus highly cross-linked polyethylene (HXLPE) by applying a level walking input using a joint simulator. Methods: Two fixed-bearing total ankle replacement systems with different types of polyethylene liners were tested: 1.) CPE sterilized in ethylene oxide, and 2.) HXLPE sterilized with gas plasma after electron beam irradiation. Three implants for each design underwent wear testing using gravimetric analysis over 5 million simulated walking cycles. A fourth implant was used as a load soak control. Equivalent circle diameter (ECD) and equivalent shape ratio (ESR) were computed to determine particle size and particle shape, respectively. Results: The mean wear rate from 1.5-5 million cycles (MC) was 2.0±0.3mg/MC for HXLPE and 16.7±1.3mg/MC for CPE (P < 0.001). The total number of particles per cycle generated for HXLPE and CPE were 0.17x106 particles/cycle and 0.53x106 particles/cycle, respectively (P < 0.001). The mean ECD of HXLPE particles (0.22 ±0.11μm) was significantly smaller than the mean ECD of CPE particles (0.32±0.14μm) (P<0.001). HXLPE particles were significantly more round than CPE particles (P<0.001). Conclusion: HXLPE liners had a significantly lower wear rate and produced significantly fewer and rounder particles than CPE liners. The results of this study suggest that HXLPE has more favorable wear characteristics for total ankle arthroplasty.

Influence of the Particle Size of LDPE on the Performance of Cu/LDPE Composites

2013 ◽  
Vol 833 ◽  
pp. 330-334
Author(s):  
Ying Tang ◽  
Yun Wang ◽  
Xian Ping Xia
Keyword(s):  
Mechanical Property ◽  
Molecular Weight ◽  
Particle Size ◽  
Tensile Strength ◽  
Elasticity Modulus ◽  
Micro Structure ◽  
Elongation At Break ◽  
Surface Hydrophilicity ◽  
The Difference ◽  
Ldpe Composites

The Cu/LDPE composites were characterized through the tests of micro-structure, mechanical property, surface hydrophilicity and releasing rate of cupric ions, in order to study the influence of the particle size of LDPE on the performance of Cu/LDPE composites. The results indicate that, with decreasing of the particle size of LDPE, Cu/LDPE composites have greater value of elongation at break and releasing rate of cupric, but smaller value of tensile strength and elasticity modulus, and the influence on surface hydrophilicity and crystalline is little. It is considered that the influence of the particle size of LDPE on the performance of Cu/LDPE composites results from the difference of both the molecular weight of LDPE and the dispersion uniformity of copper in LDPE.

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