Surface and chemical properties of surface-modified UHMWPE powder and mechanical and thermal properties of its impregnated PMMA bone cement, IV: effect of MMA/accelerator on the surface modification of UHMWPE powder

The effect of surface modification of palygorskite (Pal) on filler dispersion and on the mechanical and thermal properties of polypropylene (PP)/polypropylene grafted maleic anhydride (PP-g-MAH)/palygorskite (Pal) nanocomposites was evaluated. A natural Pal mineral was purified and individually surface modified with hexadecyl tributyl phosphonium bromide and (3-Aminopropyl)trimethoxysilane; the pristine and modified Pals were melt-compounded with PP to produce nanocomposites using PP-g-MAH as compatibilizer. The grafting of Pal surface was verified by FT-IR and the change in surface hydrophilicity was estimated by the contact angle of sessile drops of ethylene glycol on Pal tablets. The extent of Pal dispersion and the degree of improvement in both the mechanical and thermal properties were related to the surface treatment of Pal. Modified Pals were better dispersed during melt processing and improved Young’s modulus and strength; however, maximum deformation tended to decrease. The thermal stability of PP/PP-g-MAH/Pal nanocomposites was considerably improved with the content of modified Pals. The degree of crystallinity increased with Pal content, regardless of the surface modification. Surfactant modified Pal exhibited better results in comparison with silane Pal; it is possible that longer alkyl chains from surfactant molecules promoted interactions with polymer chains, thereby improving nanofiller dispersion and enhancing the properties.

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Development and Characterization of Acrylic Based Bone Cements

Journal of Biomaterials and Tissue Engineering ◽

10.1166/jbt.2022.2933 ◽

2022 ◽

Vol 12 (3) ◽

pp. 471-479

Author(s):

Aqsa Khan ◽

Ghazna Hassan Khan ◽

Eraj Humayun Mirza ◽

Alidad Chandio ◽

Maliha Mohsin ◽

...

Keyword(s):

Bone Cement ◽

Morphological Changes ◽

Chemical Properties ◽

Bone Cements ◽

Mechanical And Thermal Properties ◽

X Ray Diffraction ◽

X Ray ◽

Physical And Chemical ◽

And Chemical Properties

Bone tissue engineering has emerged as a multidisciplinary field in recent times with an aim to expedite the process of regeneration of damaged or diseased tissues. This study is an attempt to fabricate and characterize Tricalcium Phosphate (TCP) and Chitosan incorporated Polymethylmethacrylate (PMMA) based bone cement. In total two experimental PMMA based bone cements were fabricated that were differentiated by presence and absence of Chitosan. In both groups (10 and 30 wt.%) TCP were incorporated into Methyl methacrylate (MMA) monomer. PMMA was used as a control. The physical, mechanical and thermal properties of the composites were assessed. Morphological changes of PMMA after the introduction of TCP and Chitosan were observed by means of X-ray diffraction (XRD). Major peak shifts in Fourier transform Infrared spectroscopy (FTIR) spectra demonstrated the strong bonding of PMMA with incorporated materials. PMMA incorporated with 10% TCP showed the maximum wettability in absence of Chitosan. Hardness of the tested specimens decreased with increasing content of TCP which in turns enhanced ductility. It was also observed that neither of the samples showed significant degradation. The incorporation of additives enhance the physical and chemical properties of PMMA as bone cement.

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Influence of HRGO Nanoplatelets on Behaviour and Processing of PMMA Bone Cement for Surgery

Polymers ◽

10.3390/polym13122027 ◽

2021 ◽

Vol 13 (12) ◽

pp. 2027

Author(s):

Jaime Orellana ◽

Ynés Yohana Pastor ◽

Fernando Calle ◽

José Ygnacio Pastor

Keyword(s):

Graphene Oxide ◽

Methyl Methacrylate ◽

Bone Cement ◽

Reduced Graphene Oxide ◽

Sintering Temperature ◽

Structural Function ◽

Mechanical And Thermal Properties ◽

Poly Methyl Methacrylate ◽

Pmma Bone Cement ◽

Reduced Graphene

Bone cement, frequently based on poly (methyl methacrylate), is commonly used in different arthroplasty surgical procedures and its use is essential for prosthesis fixation. However, its manufacturing process reaches high temperatures (up to 120 °C), producing necrosis in the patients' surrounding tissues. To help avoid this problem, the addition of graphene could delay the polymerisation of the methyl methacrylate as it could, simultaneously, favour the optimisation of the composite material's properties. In this work, we address the effect of different percentages of highly reduced graphene oxide with different wt.% (0.10, 0.50, and 1.00) and surface densities (150, 300, 500, and 750 m2/g) on the physical, mechanical, and thermal properties of commercial poly (methyl methacrylate)-based bone cement and its processing. It was noted that a lower sintering temperature was achieved with this addition, making it less harmful to use in surgery and reducing its adverse effects. In contrast, the variation of the density of the materials did not introduce significant changes, which indicates that the addition of highly reduced graphene oxide would not significantly increase bone porosity. Lastly, the mechanical properties (strength, elastic modulus, and fracture toughness) were reduced by almost 20%. Nevertheless, their typical values are high enough that these new materials could still fulfil their structural function. In conclusion, this paper presents a way to control the sintering temperature, without significant degradation of the mechanical performance, by adding highly reduced graphene oxide so that local necrosis of bone cement based on poly (methyl methacrylate) used in surgery is avoided.

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Performance and Friction Properties of Injection Hybrid Moulds with Stereolithography Moulding Zones

Materials Science Forum ◽

10.4028/www.scientific.net/msf.514-516.1673 ◽

2006 ◽

Vol 514-516 ◽

pp. 1673-1677 ◽

Cited By ~ 6

Author(s):

Mathias G. Westphal ◽

António Sergio Pouzada ◽

Gean V. Salmoria ◽

Carlos H. Ahrens

Keyword(s):

Structural Integrity ◽

Chemical Properties ◽

Rapid Manufacturing ◽

Mechanical And Thermal Properties ◽

Layer By Layer ◽

Metallic Materials ◽

Moulding Process ◽

Photo Polymerization ◽

Geometric Precision ◽

And Chemical Properties

Stereolithography is a rapid manufacturing process that builds objects layer-by-layer based on the photo polymerization of a liquid resin. Due to the good geometric precision, this process has been used in Rapid Tooling for injection moulding. These tools are suitable for the production of short runs of parts and prototypes, where without resorting to the manufacture of a conventional metallic mould. The mechanical and thermal properties of the stereolitography resins, used in the manufacture of hybrid moulds, differ substantially from those of the conventional metallic materials. Particularly they must be known for guaranteeing the structural integrity and the thermal performance of the mould. Also the chemistry behaviour of the resin in contact with the polymer is important when tribological aspects are involved, especially during the ejection of the moulding. In this work, the behaviour of hybrid moulds with SL Vantico 5260 resin moulding cores was assessed. Several thermoplastics (iPP, ABS, PET and PA 6.6) were moulded, and their mechanical, thermal and chemical properties considered and related to the performance of the moulding process. Also, the friction properties of the SL resin in contact with the moulded thermoplastic in moulding conditions were observed and considered in the context of the performance of hybrid moulds.

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