For many years, in different countries, they have been thinking about using Polymer,Stay with farazoil Petroleum Products company in this article to check its types
modified asphalts so that they can be responsible for traffic needs. But we should say that the type of Polymer_ modified is different in each country .
But in general, the most ingredients of bitumen modifiers are thermoplastic elastomer reshttps://farazoil.com/ins
Now we are going to define polymer and Polymer modified bitumen in order to get more information.
A Polymer-a Greek-origin word where, ‘poly’ means ‘many’ and ‘mer’ means units. It is Polymer in persian.
Polymers can be thousands of monomers forming a player, these monomers are composed of carbon with oxygen.
What are the basis of classification of Polymers?
- Natural or artificial
- The Types of orrangement of monomers.
- Arrangement of chains .
- Methods of polymerizations.
- Application and thermal behaviour.
But scientifically, the best polymer modified bitumen classification is in terms of its application and thermal behaviour, so they devided it into three categories: thermoplastic, thermoset and elastomer.
They combine thermoplastic polymers such as Polyethylene, Polypropylene, Polystyrene and Polyvinyl chloride in order to obtain a mixture of polymers. These polymers melt slowly, so it is possible for a mould , they are generally solid.
In this method, the weaknesses of this material resolved and its properties improved.
Adding Polyethylene and Propylene increases the softening point and reduces the permeability of the bitumen, but because Propylene has a higher melting point, therefore by using smaller amounts of it , they can obtain the desired properties .
This type of Polymer is semi_solid which hardens due to heat and no longer softens. If they heat this material too much , it will damage. Examples of this category are polymer, polyester, polyurethane , resins and silicones.
Different between Thermoplastic and Thermoset:
- Thermoplastics are associated with intermolecular forces, which transform easily with increased temperature.
- The Thermoset has strong connections, so it is not possible to form and reprocess.
They produce Elastomers from the combination of Polymer and Elastic .Elastomers are elasticity .
In first, Elastomers have deformed due to force, then they return to the first state by removing the force. Among of their types, we can mention to Butadiene Rubber and natural rubber.
Properties of Elastomers
- They have a transfer temperature to the glass. 2. They are hard and fragile at the transition temperature to glass. 3. People make them from the sap of natural latex trees.
Thermoplastics and elastomers have many properties ,so people make the best modified bitumen called Thermoplastic from their combination.
According to the above, thermoplastics can melt but the elastomer has no melting point and is damaged by continuous heat.
The best bitumen compounds include polyurethane, copolymer, polyether, polyester, cyclic olefin copolymer and styrenic block copolymer.
Advantages of thermoplastic elastomers (TPE)
1)They have low viscosity at high temperature .
2) Thermoplastics can open in bitumen.
Characteristics of polymer _ modified bitumen
1 )High adhesion
2 )Improving the soft point and breaking bituBitumen 60/70men at the bottom point.
3 )Preventing asphalt grooves in summer by increasing the softening point.
4 )By reducing the degree of penetration , it prevents moisture into the asphalt infrastructures due to rain.
5 )Reducing cold cracking
6 )Risistance to permanent deformation.
7 )Increasing Elasticity.
You should pay attention to some points to prepare the polymer modified Bitumen 60/70 , including the type of polymer consumed , the amount and manner of producing in addition to mixing it with bitumen.
Polymer modified bitumen is incompatible with bitumen and may form a separate phase after a while. As a result, the part of bitumen vg30 is soft and elastic and the other part is hard.
Polymers enhance the properties of bitumen, therefore they use Vestenamer to solve the problem so that the combination of these two materials does not interfere with each other and creates a compatible role.
Methods to prepare Polymer modified bitumen
1 )They slowly add the Polymer _ which is like a tablet or powder _ to the bitumen.
2 )then they are combined together in the mixing tank so that obtains a uniform composition.
3 )Thermoplastics Polymer particles shrink because of high shear force mixing.
4 )Finally ,the Polymer is dispersed inside the bitumen and creates the Polymer modified bitumen
We must pay special attention to the type of bitumen used during the production of polymer modified bitumen.
Since bitumen consists of thousands of hydrocarbons and their role in bitumen efficiency is very difficult, therefore they have divided the hydrocarbons in bitumen into four categories: Aromatics, Saturated Oils, Asphalts and Resigns.
bitumen that has more aromatic oil is more compatible with the polymer.This prevents the discontinuity of bitumen and polymer and obtains a composition with uniform properties.
As a result, the values between the components must be balanced in order to establish the best connection between bitumen and polymer.
Polyphosphoric acid is like rubber powder, they consider it as a beneficial and compatible polymer which combines with bitumen