Polymer Classification

POLYMER CLASSIFICATION

Amaliya Rasyida

Material Polimer / 3 sks

Teknik Material dan Metallurgi

Fakultas Teknologi Industri

Institut Teknologi Sepuluh Nopember

http://ajigunturgeni.blogspot.com/2009/12/polymers-and-plastics-introduction.html

Basis of source Structure Applications Properties polymerization


Polymer classification Basis of source

1. Natural Polymer Alam, Tumbuhan, hewan

Polysaccharides

Protein

Nucleic acid

Natural rubber

etc



BIOPOLYMER (polymers which are naturally found in

nature; produce by living organism; polymeric

biomolecule)

(i) polysaccharrides are made of sugars (Eg. Cellulose

found in plant)

(ii) proteins of amino acids (Eg. Myoglobin i.e muscle

tissue)

(iii)nucleic acids of nucleotides (Eg. DNA genetic

material of a given organism)




Scaffold made from biodegradable polymer

A

P

P

L

I

C

A

T

I

O

N


2. Synthetic Polymer (man made polymer) Eg. Polyethylene, PVC, Nylon, Teflon, synthetic rubber, etc



Synthetic Rubber

- SBR Earliest synthetic rubber tire application

- NBR excellent resistance to oil and are extensively used for washing machine parts, hoses and flexible couplings

- Neopreneheavy-duty applications and is specifically useful at high temperatures.

- etc




High Temperature Neoprene hose


Natural Vs Synthetic Rubber?



Biopolymer vs Synthetic Polymer


Key word Biopolymer Synthetic

Structure Complex molecular assemblies that adopt precise and defined 3D structure

Simpler and more random

Process produced from renewable resources such as plant and/or living organisms

derived from petrochemicals or chemical processes

Polymer classification Structure

1. Linear Polymer Eg. HDPE, PVC, Nylons, polyesters etc.

- Single chain

- Their molecules are closely packed hence they high density, tensile strength and melting point.


Randomly oriented straight chains can

be pretty messy

Neatly packed straight chains can

make crystals!


2. Branched Polymer Eg. LDPE

They have a straight long chain with different side chains.

Their molecules are irregularly packed hence they have low density, tensile strength and melting point.



The degree to which polymer chains pack together will determine the rigidity of it.



3. Network or Crosslinked Polymers Eg. Bakelite, formaldehyde resins, vulcanised rubber etc.

Monomeric units are linked together to constitute a three dimensional network.

Elastic

Low viscosity



Elastomers are elastic polymers created by limited cross-linking.

As the number of cross-links increases, however, the polymer becomes more rigid and cannot stretch as much; the polymer will become less viscous and less elastic and might even become brittle.



How to distinguish easily between those categories?

Cross-linked polymers are usually insoluble (dont dissolve) in solvents because the polymer chains are tied together by strong covalent bonds. Other polymers are usually soluble (they dissolve) in one or more solvents because it is possible to separate the polymer chains which are not covalently linked


Polymer classification - Applications

1. Rubber (Elastomer)

High molecular weight polymer

TS 300 3000 psi

Elongation 300-1000 %



2. Plastic

- Tough substance with high MW that can be molded with/out the application of heat

- Usually stronger than rubber (TS 4000-15000 psi)

- Elongation 20 200%

Eg. PE, PP, PVC, PS, etc



3. Fiber

- Long chain characterized by highly crystalline region

- Much lower elasticity than plastics and elastomers

- High TS 20000-150000 psi

- Posses moisture absorption properties

- Light weight



Scanning electron microscope (SEM) image of a DWNT-polymer fiber which exhibits high strength and toughness. The inset shows a transmission electron microscope (TEM) image of a well ordered bundle of DWNTs which are the constituents that make up the macroscopic fibers (Image: Northwestern University, 2010)


Polymer classification Properties

THERMAL PROPERTIES

Respon suatu polimer terhadap gaya mekanik pada suatu temperatur tertentu berhubungan dengan struktur molekulnya.

Klasifikasinya didasarkan pada perilakunya terhadap kenaikan temperatur.



THERMOPLASTIC

Common thermoplastic polymers include polyethylene, polystyrene, poly(ethylene terephthalate), and poly(vinyl chloride)



THERMOSETTING

vulcanized rubbers, epoxies, and phenolics and some polyester resins, are thermosetting.


Sometimes used in semiconductors and integrated circuits



Roda Phenolic. Suhu Maksimum : 260 C. Aplikasi : Trolley untuk oven pemanggang roti, dan aplikasi lain pada suhu panas.



Some polymers (such as the polyesters) may be either thermoplastic or thermosetting. WHY?

Polyester thermoplastic -PET Unsaturated Polyester Resins (UPR) - Orthophthalates, Isophthalates, Terephthalates and Vinyl Esters



Thermosetting polyesters will be cross-linked, while thermoplastic ones will have linear structures without any appreciable crosslinking.

Polymer classification Polymerization

Polymers may be synthesized by:

1. Chain polymerization: Free Radical Polymerization i.e. Addition (three steps : initiation, propagation, and termination)

2. Step polymerization: Condensation polymerization

3. Ring Opening Polymerization



1. Addition polymer



2. Condensation polymer Two different monomer units, each containing two functional groups, react by eliminating a small molecule like water



3. Ring opening


POST TEST

1. Klasifikasikan jenis polimer berdasarkan basis resourcenya, dan jelaskan perbedaan dari kedua jenis tersebut

2. Jelaskan masing2 karakteristik dari klasifikasi polimer berdasarkan strukturnya serta berikan contohnya

3. Sebutkan secara singkat perbedaan rubber, plastik, dan fiber polimer

4. Sebutkan dan jelaskan perbedaan thermoplastik dan thermosetting

5. Sebutkan macam cara mensintesis polimer dan jelaskan secara singkat konsep dasarnya.


Polymer Classification

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