LITHENE PM4

Synonyms: polybutadiene; LITHENE PM4; LİTHENE PM4; 1,3-BUTADIENE; Buta-1,3-diene; BUTADIENE; 106-99-0; Divinyl; Vinylethylene; Biethylene; Erythrene; Bivinyl; Pyrrolylene; Butadieen; Butadien; Buta-1,3-dien; Buta-1,3-dieen; alpha,gamma-Butadiene; Butadiene monomer; NCI-C50602; Butadiene-1,3-uninhibited; CCRIS 99; 1,3 butadiene; Butadieen [Dutch]; Butadien [Polish]; 1,3-butadien; LITHENE ULTRA PM4

LITHENE PM4

LITHENE ULTRA PM4
LITHENE ultra PM4 is a low viscosity, low molecular weight, liquid polybutadiene with a medium content of 1,2 vinyl microstructure. It is extremely low in both odour and volatiles and is used as the binder in automotive sound damping sealants, polyurethane mould release systems and solvent based coating additives.
TYPICAL APPLICATIONS
Automotive sound damping sealants
Antifoaming coating additives
Non volatile drying oil in alkyd coatings
Sand binder for paving and moulds

Property Value /Unit/ Method
Vinyl 1,2 /15 - 25 /% /LTM 03
Viscosity, @ 25 C /7.0 - 9.5 /dPa.s /LTM 01
Non volatile content />99.8 % /LTM 51
Colour /200 max /Hazen /LTM 04
Typical molecular weight /1500/ Mn
Molecular weight distribution /Broad
Appearance/ Colourless to pale yellow liquid 

Application Advice & Processing
Handling - LITHENE ultra PM4 is a low viscosity, easily processed liquid polymer. It will flow readily at ambient temperatures but the product viscosity will decrease rapidly with increasing temperature and the product may be warmed to allow easier processing. Compatibility - Liquid polybutadienes are generally compatible with most aliphatic and aromatic hydrocarbon solvents. They have limited solubility in alcohols, ketones and esters. Further details are available on request. LITHENE ultra PM4 is extremely low in odour and volatiles and can be readily formulated into sulphur cured automotive sealants and acoustic dampers, cured at 160 - 200 C. LITHENE ultra PM4 provides excellent adhesion, flexibility and acoustic damping although metal adhesion can be further increased by inclusion of a functional LITHENE grade such as LITHENE ultra AL-15MA or LITHENE ultra PM4-7.5MA.
LITHENE ultra PM4 can be dried oxidatively at ambient temperatures in combination with metallic driers and can be used as a replacement to solvent in alkyd based coatings and as an air dry binder in sand for paving and moulds.
LITHENE ultra PM4 can be incompatible with many polar systems making it suitable for use in the formulation of specialised mould release coatings for polyurethanes.
Further application and formulation advice is available on request

Shipping and Storage
LITHENE ultra PM4 should be stored in a cool, dry location below +30 C (+86 F). If stored in the original sealed packaging the product has a shelf life of at least 12 months from date of delivery. Product which has been stored for longer than 12 months should betested before use. Containers which have been opened should be purged with dry nitrogen before resealing to protect the remainingproduct from oxidative skinning. Further information is available on the datasheet Storage of LITHENE Liquid Polybutadienes.
LITHENE ultra PM4 is packed in bung top 200litre steel drums containing 175kg. The minimum order quantity is one pallet (four drums). 900kg IBCs or bulk deliveries are also available.

Product Type: Polybutadiene
Master Product Number: MITM08755
Product SKUs: ITM13098, ITM13099
CAS: 9003-17-2

LITHENE ULTRA PM4-7.5MA
LITHENE ultra PM4-7.5MA is a medium viscosity, low molecular weight, liquid polybutadiene. It is very low in odour and volatiles and
is produced from LITHENE ultra PM4, adducted with 7.5 parts maleic anhydride.
TYPICAL APPLICATIONS
Adhesion promoter in automotive sealants
Rubber to metal adhesion promoter
Soft, isocyanate free electrical encapsulants

LITHENE products are 100% active, highly unsaturated, liquid polybutadienes available in a range of molecular weights and micro-structures. They are reactive, viscous liquids, have excellent low temperature flexibility, high electrical resistance and are very hydrophobic. Their excellent compatibility with hydrocarbon solvents and many rubbers makes them extremely versatile in a variety of ambient, UV and heat curable applications. Maleic anhydride grafting additonally allows the liquid polybutadienes to react with amines and polyols, while increasing polarity to enhance adhesion direct to metal. LITHENEs are widely used for: 

Sulphur cured flexible automotive sealants.

Direct to metal adhesion promotors for the automotive industry.

Sulphur or peroxide curable co-agents in rubber and TPEs.

Electrical potting resins.

Reactive plasticisers in rubber compounds.

Solvent coating defoaming additives.

Non volatile reactive coating diluents

LITHENE ultra PM4
LITHENE non functional
Name    LITHENE® ultra PM4
Appearance    colourless to pale yellow
Molecular weight distribution    broad
Molecular weight average [Mn]    approx. 1.500
Viscosity 25°C [mPas]    approx. 700
Viscosity 50°C [mPas]    approx. 200
Microstructure Vinyl 1,2 [%]    15 - 25
Microstructure cyclic [%]    -

Polybutadiene [butadiene rubber BR] is a synthetic rubber. Polybutadiene rubber is a polymer formed from the polymerization of the monomer 1,3-butadiene. Polybutadiene has a high resistance to wear and is used especially in the manufacture of tires, which consumes about 70% of the production. Another 25% is used as an additive to improve the toughness (impact resistance) of plastics such as polystyrene and acrylonitrile butadiene styrene (ABS). Polybutadiene rubber accounted for about a quarter of total global consumption of synthetic rubbers in 2012.[1] It is also used to manufacture golf balls, various elastic objects and to coat or encapsulate electronic assemblies, offering high electrical resistivity.[2]

The IUPAC refers to polybutadiene as: poly (buta-1,3-diene) as poly (buta-1,3-diene).

Buna rubber is a term used to describe an early generation of synthetic polybutadiene rubber produced in Germany by Bayer using sodium as a catalyst.
Polymerization of butadiene
1,3-Butadiene is an organic compound that is a simple conjugated diene hydrocarbon (dienes have two carbon-carbon double bonds). Polybutadiene forms by linking many 1,3-butadiene monomers to make a much longer polymer chain molecule. In terms of the connectivity of the polymer chain, butadiene can polymerize in three different ways, called cis, trans and vinyl. The cis and trans forms arise by connecting the butadiene molecules end-to-end, so-called 1,4-polymerisation. The properties of the resulting isomeric forms of polybutadiene differ. For example, "high cis"-polybutadiene has a high elasticity and is very popular, whereas the so-called "high trans" is a plastic crystal with few useful applications. The vinyl content of polybutadiene is typically no more than a few percent. In addition to these three kinds of connectivity, polybutadienes differ in terms of their branching and molecular weights.

1,3-Butadiene Polymerization.PNG

The trans double bonds formed during polymerization allow the polymer chain to stay rather straight, allowing sections of polymer chains to align to form microcrystalline regions in the material. The cis double bonds cause a bend in the polymer chain, preventing polymer chains from aligning to form crystalline regions, which results in larger regions of amorphous polymer. It has been found that a substantial percentage of cis double bond configurations in the polymer will result in a material with flexible elastomer (rubber-like) qualities. In free radical polymerization, both cis and trans double bonds will form in percentages that depend on temperature. The catalysts influence the cis vs trans ratio.
Production
The annual production of polybutadiene was 2.0 million tons in 2003.[17] This makes it the second most produced synthetic rubber by volume, behind the styrene-butadiene rubber (SBR).[15][23]

The production processes of high cis polybutadiene and low cis used to be quite different and were carried out in separate plants. Lately, the trend has changed to use a single plant to produce as many different types of rubber as possible, including, low cis polybutadiene, high cis (with neodymium used as a catalyst) and SBR.

Processing
Polybutadiene rubber is seldom used alone, but is instead mixed with other rubbers. Polybutadiene is difficult to band in a two roll mixing mill. Instead, a thin sheet of polybutadiene may be prepared and kept separate. Then, after proper mastication of natural rubber, the polybutadiene rubber may be added to the two roll mixing mill. A similar practice may be adopted, for example, if polybutadiene is to be mixed with Styrene Butadiene Rubber (SBR). *Polybutadiene rubber may be added with Styrene as an impact modifier. High dosages may affect clarity of Styrene.

In an internal mixer, natural rubber and/or styrene-butadiene rubber may be placed first, followed by polybutadiene.

The plasticity of polybutadiene is not reduced by excessive mastication.

Uses
The annual production of polybutadiene is 2.1 million tons (2000). This makes it the second most produced synthetic rubber by volume, behind styrene-butadiene rubber (SBR).[24]

Tires

Racing tires
Polybutadiene is largely used in various parts of automobile tires; the manufacture of tires consumes about 70% of the world production of polybutadiene,[18][19] with a majority of it being high cis. The polybutadiene is used primarily in the sidewall of truck tires, this helps to improve fatigue to failure life due to the continuous flexing during run. As a result, tires will not blow out in extreme service conditions. It is also used in the tread portion of giant truck tires to improve the abrasion, i.e. less wearing, and to run the tire comparatively cool, since the internal heat comes out quickly. Both parts are formed by extrusion.[25]

Its main competitors in this application are styrene-butadiene rubber (SBR) and natural rubber. Polybutadiene has the advantage compared to SBR in its lower liquid-glass transition temperature, which gives it a high resistance to wear and a low rolling resistance.[18][26] This gives the tires a long life and low fuel consumption. However, the lower transition temperature also lowers the friction on wet surfaces, which is why polybutadiene almost always is used in combination with any of the other two elastomers.[15][27] About 1 kg of polybutadiene is used per tire in automobiles, and 3.3 kg in utility vehicles.[28]

Plastics
About 25% of the produced polybutadiene is used to improve the mechanical properties of plastics, in particular of high-impact polystyrene (HIPS) and to a lesser extent acrylonitrile butadiene styrene (ABS).[19][29] The addition of between 4 and 12% polybutadiene to polystyrene transforms it from a fragile and delicate material to a ductile and resistant one.

The quality of the process is more important in the use in plastics than in tires, especially when it comes to color and content of gels which have to be as low as possible. In addition, the products need to meet a list of health requirements due to its use in the food industry.

Golf balls

A cross section of a golf ball; its core consists of polybutadiene
Most golf balls are made of an elastic core of polybutadiene surrounded by a layer of a harder material. Polybutadiene is preferred to other elastomers due to its high resilience.[30]

The core of the balls are formed by compression molding with chemical reactions. First, polybutadiene is mixed with additives, then extruded, pressed using a calender and cut into pieces which are placed in a mold. The mold is subjected to high pressure and high temperature for about 30 minutes, enough time to vulcanize the material.

The golf ball production consumes about 20,000 tonnes of polybutadiene per year (1999).[19]

Other uses
Polybutadiene rubber may be used in the inner tube of hoses for sandblasting, along with natural rubber, to increase resilience. This rubber can also be used in the cover of hoses, mainly pneumatic and water hoses.
Polybutadiene rubber can also be used in railway pads, bridge blocks, etc.
Polybutadiene rubber can be blended with nitrile rubber for easy processing. However large use may affect the oil resistance of nitrile rubber.
Polybutadiene is used in the manufacturing of the high-restitution toy Super Ball.[31] Due to the high resilience property, 100% polybutadiene rubber based vulcanizate is used as crazy balls — i.e. a ball if dropped from 6th floor of a house will rebound up to 5½ to 6th floor (assuming no air resistance).
Polybutadiene is also used as binder in combination with an oxidizer and a fuel in various Solid Rocket Boosters such as Japan's H-IIB launch vehicle; commonly is employed as hydroxyl-terminated polybutadiene (HTPB) or carboxyl-terminated polybutadiene (CTPB).