elastomers

Conventional rubbers are members of the polymer family in that they consist of long chain like molecules. these chains are coiled and twisted in a random manner and have sufficient flexibility to allow the material to undergo very large deformations. Elastomers have been available for a long time,injection mouldable thermoplastic elastomers (TPES) are replacing traditional rubbers. In addition, TPES are widely used to modify properties of rigid thermoplastics, usually improving the impact strength.



some of thermoplastic elastomers (tpe) such as polyurethane, the styrenic and the polyester are termed segmented block copolymers in that they consist of thermoplastic molecules grafted to the rubbery molecules.  At room temperature it is the thermoplastic molecule which clumps together to anchor the rubbery molecules. when heat is applied the thermoplastic are capable of movement so that the material may be shaped using conventional thermoplastic moulding equipment.

The olefinic type of tpr is the latest devlopment and is different in that it consist of fine rubber praticle in a thermoplastic matrix. the matrix is usually polypropylene and it is this which melts during processing to permit shaping of the material. The rubber filler particle then contributes the flexibility resilience to the material.
                                                                                                                                                                                                                                                                 
                                                                                                                                                                                                                                                                                                                 

Comments

Post a Comment

Popular posts from this blog

Desert Ecosystem

Image
This type of ecosystem is found in region having annual rainfall less than 25 cm. this type occupies about 5 per unit of total land masses of earth. The shortage of water and extreme temperature conditions provide varied varied biota with very poor representation. The various components of desert ecosystem are as follows. The abiotic components are high temerature and low rainfall. In the biotic components, the procedures are shrubs like grasses, trees, succulent plants. lower plants like lichens, Xerophytic mosses are also present. The consumer are insects, reptiles, rodents, birds, camel etc. The decomposers are few species of fungi bacteria etc. They are thermophlic. The desert has poor vegetation with very less amount of dead organic substances.
Read more

CPU (Central Processing Unit)

Image
The cpu is the component of a computer with circuitry to control the interpretation and execution of instructions. It performs the process part of  INPUT-PROCESS-OUTPUT cycle. In microcomputer, the components of the cpu are mounted on the main circuit board, called the motherboard. A microprocessor chip contains the circuit and special storage locations called registers - needed to perform the arithmetic-logic and control functions.                                                              The various components on the main circuit board of the personal computer processor unit are linked together by sets of parallel electrical conducting lined called buses. Different collections of these internal bus lines are used for different purpose and are given different names. These internal buses also provide an electrical intercon...
Read more

HOW TO MAKE AN OMLET

Image
Needed ingredients 1- onion 2- green chilli 3- mustard oil 2tsp 4-1 tomato chopped 5-salt to taste 6-2omlet                                                                                      at first take an pan make it hot than put 1 tsp mustard oil than crack the egg and put the yolk in the glass or pot than add some chopped onion and chopped green chilli than add salt add tomato than mixture it after that put it on to the pan than leave it for couple of minute than change the side and make it fry thats it ........ your omlet is ready now ..........................
Read more