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Rubber & Elastomers•High-Temperature & Specialty Elastomers•
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Silicone Rubber (VMQ)

Primary Designation:ASTM VMQ
Aliases:
SiliconePolysiloxaneVinyl Methyl SiliconeSilastic

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Data Completeness:0 composition elements and 1 condition-specific property values cataloged.
Omitted fields represent unverified properties. "Missing is better than invented."

Key Engineering Properties

Representative source rows, qualified by their reported conditions. Inspect the tables below for all values, limits, and source notes.

Service Temp Range
-60°C to 200°CContinuous Limit
Continuous service typically -60°C to +2...

Engineering Summary

Silicone Rubber (VMQ)—specifically vinyl methyl polysiloxane—is a semi-organic elastomer characterized by an inorganic alternating silicon-oxygen (Si-O-Si) siloxane backbone with methyl and vinyl pendant groups. The high bond energy of the siloxane bond (444 kJ/mol vs 348 kJ/mol for C-C) confers unmatched thermal stability and the broadest continuous operating temperature range (-60°C to +200°C) of any general elastomer. VMQ exhibits outstanding resistance to ozone, UV radiation, corona discharge, and weathering, possesses outstanding dielectric properties, and is physiologically inert. Its primary engineering limitations are lower mechanical tensile and tear strength and poor resistance to hydrocarbon fuels and concentrated acids.

Silicone Rubber (VMQ) Documented Applications

  • ›Automotive spark plug boots, ignition wire jackets, turbocharger hose liners, and engine gaskets
  • ›Food-contact baking molds, beverage dispensing tubing, and NSF/FDA sanitary dairy seals
  • ›Medical implants, peristaltic pump tubing, respiratory masks, and surgical catheter cuffs
  • ›Aerospace high-altitude airframe door seals and cabin environmental control ducting
  • ›High-voltage electrical insulator sheds, transformer connector boots, and electronic potting

Recognized Aliases

Source-backed commercial trade name and short designations cataloged in canonical data.

SiliconePolysiloxaneVinyl Methyl SiliconeSilastic

Elastomer Technical Profile • Silicone Rubber (VMQ)

ASTM D1418: VMQISO 1629: VMQASTM D2000: Type FC / FE / GE

Polymer backbone: Polymethylvinylsiloxane (Vinyl methyl silicone). Thermoset and cast elastomer mechanical, thermal, and chemical behavior depends strongly on compounding ingredients, crosslink density, and curing system.

Key Engineering Advantages

  • •Broadest standard thermal operating range of any commercial rubber (-60°C to +200°C continuous)
  • •Virtually unaffected by atmospheric ozone, UV radiation, corona discharge, and weathering
  • •Physiologically inert and non-toxic (widely certified for USP Class VI, ISO 10993, FDA 21 CFR 177.2600)
  • •Exceptional low compression set retention under continuous elevated heat (10–25% at 150°C)
  • •Superior dielectric insulation strength over broad frequency and temperature ranges

Engineering Limitations & Risks

  • •Low mechanical tensile strength and low tear propagation resistance
  • •Poor resistance to hydrocarbon fuels (gasoline, diesel), aromatic solvents, and high-pressure steam
  • •Vulnerable to abrasive sliding wear and sharp mechanical nicking
  • •High permeability to gases and low molecular weight organic vapors

Thermal Operating Limits & Service Profile

Min Continuous-60°C
Max Continuous200°C
Max Intermittent / PeakNot specified

Note: Continuous service typically -60°C to +200°C (-76°F to +392°F) in dry air per Parker ORD 5700 Section II (Figure 2-3). Short-term peak capability up to 250°C is highly compound-dependent (requiring heat stabilizers) and valid only in open, vented air; unvented sealed environments undergo siloxane chain reversion. ASTM D2000 Type FC/FE/GE callouts define 70h accelerated test requirements rather than continuous service ratings.

Chemical & Environmental Media Compatibility (Engineering Selection Guide)

Parker ORD 5700 Selection Ratings
Ratings represent manufacturer engineering fluid selection guidance (Parker ORD 5700 / producer design manuals). They do not substitute for batch-specific ASTM D471 / ISO 1817 laboratory immersion testing under service temperature, pressure, and dynamic stress.
Atmospheric Ozone & UVOutstanding resistance to atmospheric ozone and UV radiation; exhibits no surface crazing or degradation under extended outdoor atmospheric exposure
EXCELLENT
Engine Coolants & GlycolResistant to ethylene glycol coolants in automotive heater and radiator hoses
GOOD
High-Temperature Air (200°C)Unmatched continuous dry thermal air aging resistance
EXCELLENT
Petroleum Fuels (Gasoline/Diesel)Severe volumetric swelling (>100%) and extraction; use fluorosilicone (FVMQ) or FKM instead
NOT RECOMMENDED
Concentrated Acids & AlkalisSiloxane backbone cleaved by concentrated sulfuric, nitric, and hydrofluoric acids
POOR
High-Pressure SteamHydrolysis of siloxane bonds occurs under pressurized steam (>120°C)
POOR

Compounding & Physical Property Context

Compounding Dependency: Cure mechanism strongly influences cleanliness and set: platinum-cured LSR yields lowest volatiles, non-blooming surfaces, and zero acid by-products for medical/food use; peroxide-cured HCR requires thorough post-curing (typically 200°C for 2–4 hours) to drive off volatile acid residues.

Gas & Fluid Permeability: High gas permeability; roughly 20 to 30 times higher air permeability than butyl rubber.

Abrasion Endurance: Poor sliding and slurry abrasion resistance; unsuited for dynamic mechanical seals subject to particulate abrasion.

Tear Resistance: Low ASTM D624 Die B crescent tear strength; nicks and notches propagate rapidly under tension. (Not directly comparable to angle tear Die C or trouser tear Die T).

Compression Set (ASTM D395): Outstanding high-temperature compression set resistance; standard material for high-temperature oven and lighting seals.

Silicone Rubber (VMQ) Specifications & Designations

Standard Designations & Applicable Specifications — Semantically classified designations distinguishing primary standard identifiers, commercial trade names, and applicable specification references.

Direct Standard DesignationsDIRECT DESIGNATION
3 Primary Identifiers
Scroll horizontally for full designation data
SystemIdentifierStandard System NameClassification Notes & Provenance
ASTMPRIMARYVMQASTM D1418 Nomenclature—Ref: Standard Practice for Rubber and Rubber Latices—Nomenclature (ASTM D1418-22) / Rubber and latices—Nomenclature (ISO 1629:2013)
ISOVMQISO 1629 Nomenclature—Ref: Standard Practice for Rubber and Rubber Latices—Nomenclature (ASTM D1418-22) / Rubber and latices—Nomenclature (ISO 1629:2013)
ASTM-D2000Type FC / FE / GEASTM D2000 Classification SystemClassified under ASTM D2000 as Type FC (200°C 70h test), FE (200°C 70h test), or GE (225°C 70h test); accelerated test temperatures serve classification and do not constitute continuous service ratings.Ref: Standard Classification System for Rubber Products in Automotive Applications (ASTM D2000-21 / SAE J200:2021)
Recognized Commercial Aliases & Trade NamesCOMMON ALIAS
4 Listed
Scroll horizontally for full alias classifications
Recognized Name / AliasClassificationTechnical Usage & Context
SiliconeColloquial AliasColloquial or commercial industry synonym
PolysiloxaneCommercial AliasColloquial or commercial industry synonym
Vinyl Methyl SiliconeCommercial AliasColloquial or commercial industry synonym
SilasticCommercial AliasColloquial or commercial industry synonym
Applicable Specifications & Product Form ReferencesSPECIFICATION REFERENCE
3 Applicable Standards
Scroll horizontally for full standard specifications
Standards BodySpecification CodeSpecification Title / ScopeRelationship Type
ASTM InternationalASTM D1418Standard Practice for Rubber and Rubber Latices—NomenclatureSTANDARD · Edition: ASTM D1418-22Specification Reference
ISOISO 1629Rubber and latices — NomenclatureSTANDARD · Edition: ISO 1629:2013Specification Reference
ASTM InternationalASTM D2000Standard Classification System for Rubber Products in Automotive ApplicationsSTANDARD · Edition: ASTM D2000-21Specification Reference
Engineering Notice: Applicable specifications establish manufacturing requirements, dimensional tolerances, and test criteria for specific product forms (e.g. bus bar, wire, plate, pipe). They represent applicable technical standards, not alternative or equivalent alloy grades.

Silicone Rubber (VMQ) Mechanical Properties

Contextual Mechanical Properties & Tempers: Engineering strength, ductility, and hardness values grouped by product form, temper, and section thickness. Mechanical properties are contextual and not isotropic averages.

Showing 1 of 1 conditions
Scroll horizontally for all conditions & tempers
Product FormTemper / ConditionSection SizeTensile (UTS)Yield StrengthElongationShear StrengthFatigue StrengthHardness (Scales Preserved)Status
Standard Product FormPlatinum-Cured Liquid Silicone Rubber (Post-Cured 4h at 200°C) · 150 °C
Source values and qualifiers
Compression Set (22h at 150°C): 10–25 % (RANGE)Post-cured platinum-catalyzed LSR exhibits superior low compression set under high heat.ASTM D395 Method B / ISO 815-1Parker Hannifin Corporation, Engineered Materials Group — Parker Hannifin Corp. Catalog ORD 5700 (2018/2023), Section II (Basic O-Ring Elastomers: Table 2-2 & Figure 2-3), Section VII (Compatibility Tables) / ASTM D395-18 Method B
———————VERIFIED
Hardness Integrity Notice: Rockwell B (HRB), Rockwell F (HRF), and Superficial 30T (HR30T) scales are reported on their measured scales without cross-scale mathematical conversion.
Source: See fact-level citations

Silicone Rubber (VMQ) Processing & Fabrication

Machining, joining, forming, and thermal processing ratings cataloged from the cited authoritative technical reference.

Source: Maurice Morton (Ed.), Springer Science+Business Media

Machinability

Waterjet cutting and precision rotary die cutting; cryogenic machining used for custom surgical prototypes.

Heat Treatment & Working Ranges

Vulcanized via organic peroxide catalysts (for HCR) or platinum-catalyzed hydrosilylation addition cure (for LSR). Post-curing at 200°C for 2 to 4 hours is mandatory to volatilize cyclic siloxanes and optimize compression set.

Forming & Cold Working

High-consistency rubber (HCR) is milled and molded via compression, transfer, and extrusion; liquid silicone rubber (LSR) is processed via two-component high-speed meter-mix liquid injection molding.

Silicone Rubber (VMQ) Equivalent & Comparable Grades

Comparable Grades & Cross-References: Carefully classified cross-reference relationships for Silicone Rubber (VMQ). Comparable does not mean equivalent.

Scroll horizontally for relationship classifications & comparisons
Related MaterialFamilyRelationship ClassificationMetallurgical Notes & DifferencesStatusAction
Fluoroelastomer (FKM)rubber-and-elastomersCommonly ComparedVMQ offers unmatched low-temperature flexibility (-60°C) and lower material cost; FKM offers vastly superior fuel, chemical, and solvent resistance and higher tensile/tear strength.Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost).VERIFIEDSide-by-Side Compare →
Ethylene Propylene Diene Rubber (EPDM)rubber-and-elastomersCommonly ComparedBoth resist ozone and weathering; VMQ extends continuous temperature range to +200°C (-60°C to +200°C), whereas EPDM provides higher mechanical tear strength and lower cost up to 125°C.Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost).VERIFIEDSide-by-Side Compare →

Related Engineering & Metallurgy Guides

Contextual technical guides explaining degradation mechanisms, testing methodologies, and selection criteria relevant to Silicone Rubber (VMQ).

Material Selection18 min read

Types of Rubber: Elastomer Classification, Chemical Resistance & Selection Guide

Selecting the correct rubber is not a matter of choosing a generic flexible polymer—it requires matching molecular backbone chemistry to service temperature, chemical media polarity, dynamic fatigue, and compression set. This engineering guide classifies the 11 primary elastomer families, detailing their ASTM D1418 / ISO 1629 designations, mechanical performance envelopes, and rigorous selection algorithms.

Author: MatGrades Materials Engineering GroupRead Guide →
Material Selection17 min read

What is EPDM Rubber? Properties, Chemistry, Roofing vs Engineering Specifications

EPDM (Ethylene Propylene Diene Monomer) is the global benchmark elastomer for outdoor weathering, hot water, and automotive cooling systems. Its exceptional resistance to atmospheric ozone and steam degradation stems from an entirely saturated polyalkylene backbone with crosslinkable double bonds located exclusively on pendant side groups. This guide breaks down the chemical physics, curing kinetics, and standards governing EPDM specification.

Author: MatGrades Materials Engineering GroupRead Guide →
Material Selection18 min read

Natural Rubber vs Synthetic Rubber: Resilience, Fatigue, Chemistry & Industrial Trade-offs

Despite over a century of synthetic polymer synthesis, natural rubber remains indispensable in modern heavy engineering. Its unique ability to undergo instantaneous strain-induced crystallization grants it dynamic tear strength and fatigue endurance that synthetic random copolymers cannot replicate. However, when service conditions introduce petroleum fuels, atmospheric ozone, or temperatures exceeding 80°C, synthetic elastomers become mandatory. This guide examines the macromolecular physics and industrial trade-offs governing selection.

Author: MatGrades Materials Engineering GroupRead Guide →

Sources

Sources & Provenance Trail: Authoritative reference publications, standards specifications, and data registers cited across this material record.

ASTM International, ISO & Elastomer Engineering Technical CommitteesParker O-Ring Handbook (Catalog ORD 5700) & Elastomer Engineering Selection Guide
Development BenchmarkSTANDARDS ORG

Global engineering seal benchmark establishing continuous operating temperature envelopes (Figure 2-3), elastomer property comparisons (Table 2-2), ASTM D395 Method B compression set benchmarks, and manufacturer engineering fluid compatibility selection ratings (distinguished from raw laboratory immersion coupons).

Issuing Body: Parker Hannifin Corporation, Engineered Materials GroupRevision: ORD 5700 (2018/2023)View Source Record ↗
ASTM International, ISO & Elastomer Engineering Technical CommitteesStandard Practice for Rubber and Rubber Latices—Nomenclature (ASTM D1418-22) / Rubber and latices—Nomenclature (ISO 1629:2013)
STANDARDS ORG

Authoritative international nomenclature defining rubber acronyms and classification families.

Issuing Body: ASTM International & ISO Technical Committee ISO/TC 45 (Rubber and Rubber Products)Revision: ASTM D1418-22 / ISO 1629:2013View Source Record ↗
ASTM International, ISO & Elastomer Engineering Technical CommitteesStandard Classification System for Rubber Products in Automotive Applications (ASTM D2000-21 / SAE J200:2021)
STANDARDS ORG

Standardized classification system establishing Type and Class designations and line callouts for vulcanized rubber compounds.

Issuing Body: ASTM International & SAE International Technical CommitteesRevision: ASTM D2000-21View Source Record ↗
ASTM International, ISO & Elastomer Engineering Technical CommitteesRubber Technology (3rd Edition, Maurice Morton, Ed.) & Processing Specifications
STANDARDS ORG

Authoritative scientific treatise detailing cis-1,4 strain crystallization kinetics, network polysulfidic crosslink reversion at >70°C–80°C in conventional sulfur cures vs semi-EV stabilization, and SBR reinforcement.

Issuing Body: Maurice Morton (Ed.), Springer Science+Business MediaRevision: 3rd EditionView Source Record ↗
Intellectual Property & Provenance Notice: Mat Grades cites technical literature from recognized industry associations and standards organizations. Underlying technical standards and publication data remain the intellectual property of their respective issuing organizations.