Effect of Isocyanate Absorption on the Mechanical Properties of Silicone Elastomers in Polyurethane Vacuum Casting

Recent advances in additive manufacturing, specifically direct ink writing (DIW) and ink-jetting, have enabled the production of elastomeric silicone parts with deterministic control over the structure, shape, and mechanical properties. These new technologies offer rapid prototyping advantages and find applications in various fields, including biomedical devices, prosthetics, metamaterials, and soft robotics. Stereolithography (SLA) is a complementary approach with the ability to print with finer features and potentially higher throughput. However, all high-performance silicone elastomers are composites of polysiloxane networks reinforced with particulate filler, and consequently, silicone resins tend to have high viscosities (gel- or paste-like), which complicates or completely inhibits the layer-by-layer recoating process central to most SLA technologies. Herein, the design and build of a digital light projection SLA printer suitable for handling high-viscosity resins is demonstrated. Further, a series of UV-curable silicone resins with thiol-ene crosslinking and reinforced by a combination of fumed silica and MQ resins are also described. The resulting silicone elastomers are shown to have tunable mechanical properties, with 100–350% elongation and ultimate tensile strength from 1 to 2.5 MPa. Three-dimensional printed features of 0.4 mm were achieved, and complexity is demonstrated by octet-truss lattices that display negative stiffness.

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Effect of Particle Size of Nano-Oxides on Color Stability and Mechanical Properties of Maxillofacial Silicone Elastomers: An In Vitro Study

The International Journal of Prosthodontics ◽

10.11607/ijp.6593 ◽

2021 ◽

pp. 54-60

Author(s):

Ashika Mohan ◽

Manju V ◽

Anna Babu ◽

Krishnapriya N

Keyword(s):

Mechanical Properties ◽

Particle Size ◽

In Vitro Study ◽

Color Stability ◽

Vitro Study ◽

Silicone Elastomers ◽

Effect Of Particle Size

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The microstructure and mechanical properties of micro-scale Y2O3 strengthened 9Cr steel fabricated by vacuum casting

Materials & Design (1980-2015) ◽

10.1016/j.matdes.2014.10.075 ◽

2015 ◽

Vol 66 ◽

pp. 304-308 ◽

Cited By ~ 24

Author(s):

Zimu Shi ◽

Fusheng Han

Keyword(s):

Mechanical Properties ◽

Vacuum Casting ◽

Micro Scale ◽

9Cr Steel ◽

Microstructure And Mechanical Properties

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Evaluation of Some Mechanical Properties of a Maxillofacial Silicon Elastomer Reinforced with Polyester Powder

International Journal of Dentistry ◽

10.1155/2019/2948457 ◽

2019 ◽

Vol 2019 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Yagthan Mohammed Haider ◽

Zainab Salih Abdullah ◽

Ghasak H. Jani ◽

Norehan Mokhtar

Keyword(s):

Mechanical Properties ◽

Surface Roughness ◽

Tensile Strength ◽

Hardness Test ◽

Silicone Elastomer ◽

Control Group ◽

Silicone Elastomers ◽

Tear Strength ◽

To Come ◽

Post Hoc

Maxillofacial silicone elastomers are used to replace and reconstruct missing facial parts for patients with trauma or a certain disease. Although commonly favorable silicone elastomers are not ideal in properties, many studies have been carried out to improve their mechanical properties and to come out with ideal maxillofacial prosthetic materials, so as to render patients with the best maxillofacial prostheses. The aim of the current study is to evaluate the effect of addition of different concentrations of polyester powder on hardness, tear strength, surface roughness, and tensile strength of maxillofacial A-2186 RTV silicone elastomers. Polyester powder was added to the silicone elastomer in the concentrations of 1%, 3% and 5% by using an electronic digital balance, compared with the control group of 0% polyester filler. The shore A hardness test was done according to ASTM D 2240 standards. The tear test was done according to ASTM D624 type C standards. The tensile test was done according to ISO specification number 37:2011. The surface roughness test was performed according to ISO 7619-1 2010 specifications. The data collected were then analyzed using one-way analysis of variance (ANOVA) and post hoc and Fisher’s LSD tests. All three groups showed a highly significant increase in tear strength, tensile strength, hardness, and roughness, compared to the control group. Reinforcement of A-2186 Platinum RTV Silicone Elastomer with 5% polyester significantly improved the mechanical properties tested in this study.

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Behaviour of Vacuum Casting Plastic Composites Under Different Treatments of Banana Fibres

Volume 12: Processing and Engineering Applications of Novel Materials ◽

10.1115/imece2010-39782 ◽

2010 ◽

Author(s):

M. D. Monzo´n ◽

Z. Ortega ◽

A. N. Beni´tez ◽

P. M. Herna´ndez ◽

M. D. Marrero ◽

...

Keyword(s):

Mechanical Properties ◽

Maleic Anhydride ◽

Research Work ◽

Natural Fibers ◽

Vacuum Casting ◽

The Sustainable Development ◽

The Matrix ◽

Efficiency Factors ◽

And Behavior ◽

Fibre Matrix

Nowadays, the natural fibres market is having an important growth due to the commitment of contemporary society with the sustainable development that leads the natural resources preservation and the environment protection. Fibres from banana food wastes provide high mechanical properties related to other natural fibers such as flax, sisal, hemp, etc. The aim of the present research work is to compare different banana fibres processing in order to improve the matrix fibre adhesion and behavior of fibre under processing conditions. Simple Anova analysis has been implemented on four different formulations: 1. No fibre processing, 2. Alkaline processing with Caustic Soda (NaOH), 3 Maleic Anhydride, 4. Combination of Soda and Maleic Anhydride. Several samples of MTT 8040 resin, under vacuum casting, with silicone moulds, conditions, have been done. Mechanical properties and efficiency factors of adhesion fibre-matrix have been determined and compared.

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Design of Novel Treated Silica Xerogels: Synthesis, Property and Reinforcement in Silicone Elastomers

MRS Proceedings ◽

10.1557/proc-520-269 ◽

1998 ◽

Vol 520 ◽

Cited By ~ 1

Author(s):

Q. Deng ◽

G. T. Bums ◽

J. R. Hahn ◽

C. C. Reese ◽

J. D. Preston ◽

...

Keyword(s):

Mechanical Properties ◽

Surface Area ◽

Silica Xerogels ◽

Silicone Elastomers ◽

Surface Areas ◽

Reinforcing Fillers ◽

Controlled Porosity ◽

The Relationship ◽

Filler Structure

ABSTRACTTreated silica xerogels with controlled porosity and surface area were prepared by the in-situ treatment of hydrogels with hexamethyldisiloxane in the presence of isopropyl alcohol. The resulting hydrogels were hydrophobic and readily transferred to organic solvents allowing their isolation. The surface area and porosity of the xerogel were controlled by varying the pH, time and temperature used to aggregate the hydrogel prior to treatment. The treated xerogels were evaluated as reinforcing fillers in silicone rubber formulations. When the bases were crosslinked with peroxides, silicone elastomers with acceptable mechanical properties were obtained. The relationship between the surface area, porosity and the type and degree of surface treatment of the xerogel, and its reinforcing ability was studied. In general, the mechanical properties of the elastomer increased as the filler structure increased; however, xerogels with higher surface areas were more difficult to incorporate and gave higher plasticity bases.

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