The term Silicone in material sourcing is a linguistic minefield and presents great confusion for many people. Searching for silicone using the Internet can yield results such as shoe box packets that absorb moisture, as well as high-heat gaskets used on EVs.
These two products are not the same thing. Contributing to this confusion is the use of terminology translation in the manufacturing sector, specifically in the Chinese language, where the word Guijiao can refer, in a very broad sense, to both materials.
In fact, in professional English and chemistry, Silicone Rubber and Inorganic Silica Gel are two very different materials with very different uses. This should serve to clarify and help consumers to understand the differences between Organic Silicone Rubber and Inorganic Silica Gel.
The Terminology Trap: Clearing the Air
First, let’s clear up some of the confusion around the names associated with cross-border procurement before you start using chemistry.
1. Inorganic Silica Gel - (Also Known as “Absorber”
Silica Gel is what chemists and those who package products are referring to when they say “Silica Gel” – hard porous granules that are used for drying things out.
Chemical Composition – Inorganic
Common Form – Clear beads or white powder
2. Silicone Rubber - (Also Known as “Elastomer”)
Silicone is a polymer used to produce various parts in engineering and design. Silicone is organic, meaning it contains carbon atoms and derives its composition from silicon, but predominantly it is an organo-silicon hybrid.
Silicone can take on many different forms, such as sheets, tubes, liquids and molded parts.
Note: If you are visiting Hong Kong or Taiwan, you may hear the word Xi-li-kang, which is a Chinese word that phonetically translates to the English word “silicone” and refers specifically to silicone as a rubbery material; it does not refer to the desiccant that absorbs moisture from the air.
The Technical Showdown: Inorganic vs. Organic
Choosing suitable materials requires an understanding of the differences between inorganic silicate gel and silicone rubber (polysilicone) in terms of chemical composition.
1. Chemical Composition
Inorganic Silicate Gel: This product is a very active adsorptive material, and it consists of amorphous silicon dioxide. The production is accomplished by the reaction of sodium silicate with sulphuric acid and then aging and bathing in acid. The "magic" of the product is its unique structure, which contains a large number of nanometer-sized pores designed to trap moisture.
Polysilicone or Silicone Rubber: This product is a Polymer having a high molecular weight in combination with a chemical structure that has alternate Silicon and Oxygen atoms for its back-bone; in addition, the Silicon atoms within the polymer contain Organic Groups, which may include methyl, vinyl and phenyl.
Modification: The addition of phenyl groups creates Low Temperature Resistance (-110°C); and the addition of trifluoropropyl groups creates Fuel/Oil Resistance (Fluorosilicone).
2. Physical Properties Comparison
| Особенность | Inorganic Silica Gel | Silicone Rubber (Organic) |
| State | Hard granules, beads, or irregular rocks | Soft elastomer, liquid, or gel |
| Tactile Feel | Hard, brittle (like glass or rock) | Soft, rubbery, stretchable, flexible |
| Primary Function | Adsorption (Traps water/gas) | Sealing, Insulation, Flexibility |
| Thermal Stability | Heat resistant, but loses function (desorption) at high heat | Excellent. Operates from -55°C to 250°C |
| Reactivity | Inert (reacts only with strong alkali/HF) | Inert, biocompatible, high oxygen permeability |
Applications: One "Drinks," The Other "Seals"
Because their properties are opposite, their applications rarely overlap.
1. Applications of Inorganic Silica Gel
Leveraging its microporous structure:
Desiccants: Moisture control packets in electronics, leather goods, and food packaging.
Purification: Chromatography silica used in labs for purifying pharmaceuticals and separating DNA.
Carriers: Used as a substrate for industrial catalysts.
Stabilizers: Used in beer and beverage filtration.
2. Applications of Silicone Rubber
Leveraging its elasticity and weatherability:
Electronics: Waterproof gaskets, conductive keypads, and potting gels for PCBs.
Power & Energy: High-voltage insulators and cold-shrink cable accessories (replacing ceramics).
Medical & Consumer: Baby nipples, medical-grade tubing, and respiratory masks (Biocompatible, FDA/USP Class VI compliant).
Automotive: Engine gaskets, hoses, and spark plug boots (Oil and heat resistance).
Заключение
Let's get down to business and forget the big words.When you mix these 2 substances, it's like mixing up a sponge with a wetsuit. They are both concerned with water, but they work with it in very different ways.
To help you avoid making a huge mistake in sourcing something, here is a quick checklist:"SQUISH"TEST If it is stiff and hard with sharp edges, that's Silica Gel — a product to keep things dry.
If it is flexible and stretchy and regains its shape, then that is Silicone Rubber — a product used for constructing parts.
SUPPLIERCHECK
If a supplier uses the phrase "Xi-li-kang" or "Organic Silicon," you know that you're getting Silicone Rubber for molding.
So remember, Silica Gel is used to absorb moisture and Silicone Rubber is used to keep it out.
С технической точки зрения это синтетический каучук (эластомер). Хотя и пластмассы, и силиконы относятся к полимерам, они отличаются по структуре основной цепи. Пластмассы (такие как ПЭ или ПП) имеют углеродную основу и получаются из сырой нефти. Силиконовый каучук имеет кремний-кислородный остов (полученный из кварцевого песка), что придает ему уникальные свойства, более близкие к свойствам камня (термостойкость), чем к свойствам пластика.
A: Именно в этом и заключается путаница с аббревиатурой #1 в отрасли.
Кремний (без буквы 'e'): Природный химический элемент (Si), содержащийся в песке и горных породах. Это твёрдый, хрупкий металл, используемый для производства компьютерных микросхем.
Силикон (с буквой 'е'): Искусственный гибкий материал, полученный на основе кремния. Если он мягкий, эластичный или жидкий, то это Силикон.
Это полуорганический синтетический материал. Он занимает уникальное промежуточное положение. Он не является "натуральным", как латекс (получаемый из деревьев гевеи), но и не является чисто синтетическим материалом на нефтяной основе, как ПВХ. Благодаря своему минеральному происхождению (песок) он обладает большей химической стойкостью, чем органические каучуки.
Нет. В отличие от термопластов, силикон представляет собой термореактивный материал. После отвердевания он не плавится и не возвращается в жидкое состояние. Он сохраняет свою форму до 250 °C (482 °F). При воздействии экстремально высоких температур (свыше 400 °C) он со временем станет хрупким и разложится на порошок кремнезема, но никогда не расплавится.
Это, пожалуй, самая устойчивая к воздействию погодных условий резина из всех существующих. Поскольку её молекулярная связь (Si-O) схожа с кварцем, она практически не подвержена воздействию Ультрафиолетовое излучение, озон и дождь. В то время как шины из натурального каучука растрескиваются уже через несколько лет, силиконовые изоляторы на линиях электропередачи могут прослужить от 20 до 30 лет под прямыми солнечными лучами без потери качества.
Они имеют одинаковый химический состав, но разные формы:
HCR (резина высокой вязкости) / HTV: Поставляется в виде цельных блоков (подобно глине). Наилучшим образом подходит для прессования, экструзии (изготовления труб) и производства недорогих деталей.
LSR (жидкий силиконовый каучук): Поставляется в двух канистрах с жидкостью (A+B). Идеально подходит для высокоточного литья под давлением, автоматизированного серийного производства и изготовления деталей оптического качества.
No. It does not break down into micro-plastics like water bottles, but it also does not compost. It will sit in a landfill for decades without leaching chemicals.
Yes, but not in your curbside bin. It requires a specialized recycling facility. Cured silicone can be ground down into crumbs (for playground mats) or chemically depolymerized back into silicone oil (a process currently being scaled up by major manufacturers like Dow and Wacker).