Application and development of the life of a silicone medical silicone rubber-Iota

Products

News

Office Address:	Sunmoon Science Park, 985 Xingzhong Road, High-Tech Zone, Bengbu, China
Factory Address:	Mohekou Industrial Park, Huaishang District, Bengbu, Anhui, China
Contact:	Nathan Zhang
Phone:	0086-552-19805521900
FAX:	0086-552-3822922
Mobile:	19805521900/18119733779
WebSite:	www.siliconeoil.cn www.siliconeoil.net
Email:
QQ:	729118868

Service > Application and development of the life of a silicone medical silicone rubber

Application and development of the life of a silicone medical silicone rubber

Silicone rubber is one of synthetic rubber, is a dimethyl siloxane monomers and other organic silicon monomer polymerization under acidic or basic catalyst, relative molecular weight is generally 400,000 to 500,000. Medical polymer materials apart from raw materials to finished products must be strictly controlled, but also must meet the following requirements:
Chemically inert, not tissue fluid erosion; compatible with the surrounding tissue, causing inflammation does not react with the organism, foreign body reaction as little as possible;
Do not cause cancer, does not cause allergic reactions, surface coagulation; implanted in the body, long-term use without loss of tensile strength, elasticity and other mechanical properties;
Deformation, able to withstand sterilization measures necessary; easily processed into complex shapes and the like.
Silicone rubber has excellent physical properties, non-toxic, odorless, good compatibility biological phase, no adverse effects in vivo implantation of biological aging resistance, high temperature resistance, good ventilation, and has good mechanical properties, in line with medical high Requirements molecular materials.

Silicone rubber as an excellent medical polymer materials, whether in the rubber industry, or in the medical field have been the concern of professionals. This is because, first, it is used as a rubber material for medical technology content, low cost, high value-added, very substantial economic benefits; Second, the use of silicone rubber medical properties, both in solving many problems of medicine, but also so that patients obtain satisfactory results; third, its wide range of sources, ease of production and finishing, with good social and economic benefits.

Medical use of silicone rubber
Silicone rubber according to the medical, pharmaceutical and health industry applications can be roughly summarized as follows: long-term retention in the human body organ or tissue substitutes and short-term retention in the human body for medical devices, orthopedic medical devices, drug delivery systems, such as several in vitro supplies aspects.
1, long-term retention in the human body organ or tissue substitutes
Such organ or tissue including hydrocephalus drainage devices, artificial lung, retinal implants, artificial meninges, throat, artificial finger, palm joints, artificial eardrum, a dental impression and denture tissue surface soft liner, artificial heart valves Accessories and so on.

2, short-term retention in the human body auxiliary medical devices

Silicone Rubber Products Medical Devices Division as an auxiliary body of short-term indwelling body, play rehydration, rescue, drainage injection, anti-blocking or anti-foaming effect, these instruments include intravenous catheter, catheter, arteriovenous fistula outside, abdominal dialysis tubes, contact lenses, blood transfusion, pressure relief tube, chest tube, endoscopy tube, snorkel otitis media, catheter and nasal intubation.

3, on the key components of medical devices
These include artificial heart pump blood transfusion tubes, membrane type artificial heart-lung machine, fetal attract and artificial blood circulation devices.
4, used in cosmetic and repair areas
The past 20 years, the silicone rubber in cosmetic and prosthetic has also made a wide range of applications such as: face with silicone rubber repair defects, treatment external ear defects, skull and chest performed cosmetic surgery and repair internal organs, etc., there is now controversy a lot of artificial breasts.
5. Application in Drug Delivery System
Prolong the effect of drugs and improve drug specificity and safety of pharmaceutical research is an important issue. 1957 silicone rubber material begins to be used as wrapping material control drug release, 1964 Folkman and Long first show, in a closed silicone rubber tube, the drug can be slowly released, and for a long period of time can be maintained at a certain body drug concentration, with further research, it was found that silicone rubber has good permeability and permeability is an ideal drug delivery materials; drugs took advantage of this characteristic of silicone rubber, for effective control through the silicone rubber release and slow diffusion. Use silicone rubber control drug release there are two main ways: First, encapsulated, that is the core of the drug, topical silicone rubber thin film encapsulation; this way the drug is equivalent to a polymer membrane vesicles as a drug "warehouse" , also known as depot formulations or film. Second, it dispersed particles, namely drugs silicone rubber particles dispersed in the matrix, which along with accelerated growth rate of drug release and time becomes small; but the manufacturing is relatively simple, just the drug and the silicone rubber mixing, and molding can.
6, used in vitro supplies
Because the silicone rubber film has good oxygen permeability, carbon dioxide permeability properties similar to human skin and the amount of evaporation of moisture, non-toxic to humans, harmless, not allergic, not easy to cause foreign body reaction or rejection, etc., in the Economic and nylon, After polyester fiber enhancements used as an artificial skin.
7. Other medical applications
In addition to the above applications of silicone rubber. Also used in bio-medical engineering. Including medical devices, medical electrodes, biological implantable sensor packaging materials.

Silicone rubber material in the medical device application notes
1, medical tubing

Medical products require a high degree of purity and noble material, the peroxide-cured silicone rubber is increasingly being addition or substitution of platinum cured silicone rubber. Name "addition cure" comes from its chemical reaction during crosslinking: Under catalytic precious metals (such as platinum), SiH functional groups multifunctional crosslinking agent molecules are bonus on vinyl polysiloxane the vinyl double bond molecule, thereby crosslinking agent molecules with the vinyl polysiloxane molecules through chemical bond together as one. Since a plurality of SiH crosslinker molecule containing functional groups, so that a cross-linking agent molecule may react with a plurality of polysiloxane polymer chain, form a crosslinked structure. This addition crosslinking reaction at room temperature is quite rapid, and therefore must be in gel polymerization inhibitor is added, the platinum catalyst activity is reduced at room temperature, to retard unwanted cure at room temperature. After the temperature was raised, the polymerization inhibitor is to drive away, catalyst recovery catalyze the crosslinking reaction. The polymerization inhibitor is a platinum catalyst affinity than vinyl polysiloxane molecule substances, such as peroxides, hydrated peroxide, acetylenic derivatives and the like. And, if not controlled, such substances as well as sulphides and amines can also become a permanent platinum catalyst deactivation agent. Therefore, the addition curing silicone rubber must be processed in a clean environment, preferably separated from other organic materials processing zones. Typically, a platinum-catalyzed silicone rubber is two-component prior to use in the form of supplies. When the two components are mixed, the time platinum-catalyzed silicone rubber that can be used is shorter, so this material is generally extruded and vulcanized need within a few hours after mixing. Of course, according to the latest progress in the platinum catalytic technology, one-component addition cure silicone rubber has been developed. This material in a "ready to use" in the form supplied to the manufacturer, the catalyst and a polymerization inhibitor were pre-mixed in silicone rubber, so no need to be mixed before use. This is usually valid for three months of a one-component addition cure silicone rubber for manufacturers to provide a "ready to use" the convenience, but also reduces costs for manufacturers. In the past, high tear resistance, peroxide-cured silicone rubber is standard peristaltic pump works material with a long life and the advantages of small size tolerances. However. Peroxide-cured silicone rubber secondary vulcanization needed to remove acidic by-products, and which can be extracted out of content was also generally a platinum catalyzed silicone rubber ratio is high. Most existing platinum-catalyzed silicone rubber product is to improve the tensile and tear strength and design, so little regard for other properties, such as elastic memory, compression, rebound and lag and so on. And because peristaltic pump tubing need to withstand cyclical squeeze millions of times, these other properties can affect the dynamic fatigue failure of performance silicone rubber, which largely affect the life of the catheter. Recently, a number of these key performance optimization platinum-catalyzed silicone rubber products have been developed out. Previously, silicone rubber tube with a medical device is a tube formed by extruding continuous annular cross-section, and then cut to length for a particular device. Although the inner diameter and wall thickness tolerances can be controlled within a few thousandths of inches, but this is a continuous extrusion process may cause some deviation tube torus. Recently, liquid injection molding (LIM) silicone rubber provides us with another high-quality, cost-effective way of silicone rubber products. Liquid injection molding silicone rubber is a two-component, platinum catalyzed, pumpable silicone rubber products. This silicone rubber can be thermosetting materials for injection molding, compression molding at high temperatures. Compared with the extrusion process, the molding process can produce complex shape, size precision products. For example, there is molded integrally with a flange and guided, can pump and pipe fitting and tightly integrated sensors intestinal feeding tube pump. This ability to more precisely control the shape of the catheter technology to make more sophisticated, better performance of new infusion pumps can be achieved. Thus, the liquid injection molding silicone rubber will have a wider range of applications in the future many new medical devices. Platinum-catalyzed silicone rubber that can be used in many excellent material properties of pharmaceutical products, emerging-component products not only make it easy to produce extruded products are also easy to produce molded products. Specially developed peristaltic pump platinum-catalyzed silicone rubber can achieve performance peroxide-cured silicone rubber. These new silicone rubber material with original low extractable content, non-peroxide byproducts, and has the advantage of a smooth surface. Moreover, they have good elastic memory, low elasticity lag, low permanent compression ratio, improves the accuracy of the peristaltic pump tube life and flow rate. Injection molding of silicone rubber provides us another new way, giving medical devices with new features and higher reliability.

2, the medical electrode plate

Since the electrode plate is an element of human contact, requiring plastic material soft and comfortable, showing a physiologically inert, non-toxic to humans, no stimulation to skin, breathable performance better. During use, to be able to withstand repeated high temperature and pressure, sterilization of medical alcohol or potassium permanganate solution without compromising performance. Silastic just accommodate these requirements, it is extremely suitable as a substrate. Made of conductive silicon rubber, while maintaining the characteristics of the silicone rubber itself, but also has conductivity, in medical equipment, electrical and electronic fields is the largest amount of conductive rubber, conductive rubber is the preferred substrate.
Basic constituent materials of the medical electrode plate is able to meet the requirements of medical materials and silicone rubber substrate actual requirements and it has a good conductive properties of conductive filler, if the auxiliary component with the other can make better performance . Insulating rubber conductive filler is a conductive material mainly. Among the conductive material, carbon black is the first to be used in a conductive material, among which more famous acetylene black. It is used acetylene gas obtained by thermal decomposition, referred alkyne black. Acetylene black with high conductivity, compared with the metal powder, it has some reinforcing effect of rubber, excellent processing performance, small impediment to vulcanized rubber, good heat resistance. Acetylene black due to its high structural and conductive. In the agglomeration of carbon black in the state structure, gather the highest state of acetylene black, furnace black above the channel black. Carbon black particles chain and high network structure can be formed with a conductive body, while low structure carbon black, the lack of particle chains, poor conductivity. Conductive rubber conductive mechanism depends on the conductive material used. Carbon-based electrically conductive filler, such as graphite, carbon black, etc., by itself, while a current of electrons migrate in a polymer; metal-based filler is itself brought into contact with each other to move the free electrons generated current. Conductivity mechanism on carbon-based conductive polymer, there are several theories, including the conductive path and tunnel effect theory. Now it believes that "electron tunneling effect" that the tunnel effect is produced by the principle of conductivity. The applied voltage is formed between the adjacent thin layer of polymer and carbon black particles in an electric field interval, so that electrons can pass current generated depends on the electronic conductive particles between the two crossed paths. The role of the conductive filler in the conductive rubber is essential, therefore the characteristics and content of the conductive filler in rubber, rubber of molecular weight, degree of crosslinking and other fillers, and other operating conditions conductive to the final It has an impact. Conductive filler loadings of conductive rubber has a decisive role. Silicone rubber mixed with carbon black added depends on the amount of the conductive filler. With increasing amounts of filler, a conductive polymer conductivity growth is small, but more than a certain percentage of the amount of filler (ie penetration limit), the conductivity will rise exponentially. A high degree of structure, the smaller the particle size of acetylene black can impart high conductivity and rubber mechanical properties. Since the particle size is small, when the structure is high, the ratio in certain conditions, tend to form a continuous structure carbon black and conductive. Shear strength test showed a conductive silicone rubber material depends on the viscosity ratio of the carbon black, and the shear strength of the polymer. Ultimate conductivity and processing properties of the product are similar relationship, but more difficult to distinguish between the various parameters of the role. Processing performance and viscosity conductive silicon rubber material, curing properties can be within a certain range according to user needs adjustment. Different methods of curing conductive rubber impact. In the carbon black filled silicone rubber with the addition curing, peroxide curing, radiation curing and polymerization filling method will cause different final conductivity, wherein the polymer is filled into the legal vulcanized rubber has the highest electrical conductivity. This is due to the use of this method, the filler particles to maximize dispersed in the polymer.

The development direction of medical silicone rubber
With Biomedical Engineering. Tissue engineering development, technical and performance requirements for medical materials increasing. On silicone rubber, how to make it fully applied bioengineering and tissue engineering is the main direction of future research. Such as: The biosensor is today striking a biotechnology. Miniaturization, adaptability and living biosensors, will become an important issue associated with artificial organs.
In short, the medical silicone rubber in the life sciences, medical devices, pharmaceuticals, etc. has been extensive and important applications, but there is huge potential to be tapped, as the study of the development of life sciences and bio-materials, it will do for human society a greater contribution.

Feedback to "Iota Silicone Oil (Anhui) Co., Ltd."