UNIT 2 B
8. Enlist the different type of common engineering polymers.
A.
·
Acrylonitrile butadiene styrene (ABS)
·
Nylon
6
9. What are the
different types of plastics?
A.
·
Polyethylene
terephthalate (PET or PETE)
·
High-density polyethylene (HDPE)
·
Polyvinyl chloride (PVC)
·
Low-density polyethylene (LDPE)
·
Polypropylene (PP)
·
Polystyrene (PS)
10. What are the
special properties of plastics that make them useful engineering material?
A.
·
Strength. The plastics
are sufficiently strong and can be used for load bearing structural members
·
Weather Resistance
·
Fire Resistance
·
Durability
·
Dimensional Stability
·
Chemical Resistance
·
Thermal Resistance
·
Working Conditions
11. Write the
applications of PVC.
A.
·
Signs
·
Flooring
12. Define the term
FRC.
A. A fiber-reinforced composite (FRC) is a composite building material that consists of three components:
(i) the fibers as the discontinuous or
dispersed phase,
(ii) the matrix as the continuous phase, and
(iii) the fine interphase region,
also known as the interface. This is a type of advanced composite group,
which makes use of rice husk, rice hull, and plastic as ingredients. This
technology involves a method of refining, blending, and compounding natural
fibers from cellulosic waste streams to form a high-strength fiber composite material
in a polymer matrix. The designated waste or base raw materials used in this
instance are those of waste thermoplastics and various categories of cellulosic
waste including rice husk and saw dust.
FRC is high-performance
fiber composite achieved and made possible by cross-linking cellulosic fiber
molecules with resins in the FRC material matrix through a proprietary
molecular re-engineering process, yielding a product of exceptional structural
properties.
Through this feat of
molecular re-engineering selected physical and structural properties of wood
are successfully cloned and vested in the FRC product, in addition to other
critical attributes to yield performance properties superior to contemporary
wood.
This material, unlike
other composites, can be recycled up to 20 times, allowing scrap FRC to be
reused again and again.
The failure mechanisms in
FRC materials include delamination,
intralaminar matrix cracking, longitudinal matrix splitting, fiber/matrix
deboning, fiber pull-out, and fiber fracture.
13. State the characteristics of ceramics materials.
A. PROPERTIES OF CERAMIC MATERIALS
The following
properties of ceramic materials make them useful for engineering applications
1. Mechanical properties
2. Electrical properties (including magnetic properties)
3. Chemical properties
4. Thermal properties
5. Optical properties
6. Nuclear properties.
.
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14. Classify the
ceramics.
A. 
15. State the
characteristics of glass.
A. Characteristics of glass:
·
It is hard brittle material.
·
It is weather resistant.
·
It can be given a high polish.
·
It can absorb, reflect and refract light.
·
It is an excellent insulator against
electricity.
·
It can be blown, drawn and pressed to any shape.
·
It is amorphous and brittle.
·
It is possible to change some of its properties
like hardness, fusibility and refractive poer etc to suit different purposes.
·
It can be frosted by sand blasting.
·
It is incombustible.
·
It is greater dimensional stability.
·
It has a compatibility with or material.
·
It
is non rotting material.
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