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Polymer physics, polymer chemistry and chemical technology related to Avans Hogeschool (Hogeschool Brabant), Faculteit Techniek & Natuur, Breda

 Avans Hogeschool, Faculteit Techniek & Natuur

Examination Papers

The following examples of preliminary examination papers in Dutch come on students' requests.
Chemische Procestechniek  Dutch
Polymeren I  Dutch
Polymeren II  Dutch

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Supporting Calculator Software

Burgers' Creep

In what way will a sample of a viscoelastic material like an amorphous polymer elongate in course of time, if it is subjected to a constant stress? Based on the Burgers model the mechanical behavior is given numerically as well as graphically. Read more...

 Burgers' Creep

Burgers' Stress Relaxation

A viscoelastic material like an amorphous polymer is stretched to a given value of the strain. How does the stress necessary to maintain the constant strain, changes as a function of time? Grounded on the Burgers model, the question is numerically and graphically answered.

Copolymer Composition Drift

During the synthesis of a bipolymer, the composition of the instantaneously formed copolymer chains usually changes as the polymerization reaction proceeds. The changing composition is plotted as a function of the also changing composition of the monomer feed, starting from the initial feed composition and depending upon two given reactivity ratios. Read more...

 Copolymer Composition Drift

Rectification (Distillate Composition Calculation)

According to the McCabe-Thiele method the program calculates the composition of the distillate obtained from a two component liquid mixture with known composition and relative volatility, boiling under a column with a given number of theoretical plates and a given reflux ratio. Read more...

Rectification (Calculation of the Number of Plates)

This program can be used to determine the total number of theoretical plates in a batch rectification unit, according to McCabe-Thiele. It needs input values of the relative volatility, the composition of the boiling mixture, the reflux ratio and the distillate composition. Read more...

 Rectification (distillation)

As is evident from many experiments, like the membrane osmometric determination of the number average molecular weight of a polymer, or the determination of the viscosity average molecular weight according to Mark-Houwink, a regression program offers in more respects a splendid relief in many working-outs. You can find regression programs elsewhere on this web site.


Hein ten Horn
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Models of Matter

Atomic orbitals

 s orbital  p orbitals  d orbitals (..)




 orbitals of neon
orbitals of neon
(1s, 2s, 2p)

Some hybrid atomic orbitals

 sp2 hybridization  sp3 hybridization  sp3d hybridization  sp3d2 hybridization

in ethylene,
borane (BH3)

ammonia (NH3)

in PCl5,
(central I)

in SF6

Three-dimensional representation of a molecular model

 sp³d hybridization

sp³d hybridization in a PCl5 molecule

A space-filling model of a dendrimer

 A dendrimer

(Dendrimers are repeatedly branched molecules with precise, nano-sized composition and well-defined three-dimensional shapes.)

Models of DNA (Crick and Watson's double helix, 1953)

 DNA model (Watson, Crick, 1953)  DNA model

Line-angle formula of chlorophyll a

 Chlorophyll a

The line-angle formula is also called a skeletal structure, or a stick figure.

 Chlorophyll enables plants to synthesize carbohydrates.

(Using red and blue light absorbed from the sunlight chlorophyll enables plants to synthesize carbohydrates, thus converting light energy into chemical energy.)

Full structural formula of polyurethanes (PU)


In a full (or expanded) structural formula all the individual chemical bonds should be visible. In the general polyurethane formula, however, the groups R' and R" haven't been written out, since their structures depend on the many distinguishable polyurethane types. If, for instance, the polymer is made from the monomers hexamethylenediisocyanate and ethylene glycol only, the groups R' and R" are (CH2)6 and (CH2)2 respectively. The following structures show the repeating dyad in this particular polymer chain.

Full structural formula

 Full structural formula of the repeating unit in a particular polyurethane chain

Condensed structural formula

...CONH(CH2)6NHCOO(CH2)2O... or

Ball-and-stick model

 A ball-and-stick model of the repeating unit in a particular polyurethane chain

Lewis structure

 Lewis structure of the repeating unit in a particular polyurethane chain

Space-filling models

 Space-filling model of the repeating dyad in a particular polyurethane chain

Space is filled up to 100 % of the van der Waals radius
 Space-filling model of the repeating dyad in a particular polyurethane chain

Space-filling: 75 % of the van der Waals radius
Both space-filling models are drawn to the same scale, but from a different viewing angle. In a real chain the distance between both ends of a repeating unit is continuously changing and roughly amounts to 1,5 nm.

Some polyurethane containing products

(move mouse cursor over pictures)

 Reinforced polyurethane  Polyurethane products  PU wheels (Trikke)
   Polyurethane foam tire (flat-free)  PU bumpers and grills
 Land form model (raised relief)  Polyurethane landscape model  Polyurethane foam can be sprayed into many shapes; it dries in seconds.
 Vibration damping foam  Rigid foam insulation board  Fireproof polyurethane foam
 Polyurethane window frame (aluminium core)    Adhesives; flexible and rigid foams
 Flexible foams  Flexible foams for bedding, furniture, and rug underlays  Flexible foams with open cells
 Polyester with Lycra  The polyurethane fiber Lycra (DuPont) is also known as Elastane (EU) and Spandex (US)  Cotton jeans blended with Lycra
 At the left: polyester, Lycra (94/6) - Right: nylon, Lycra (90/10)  Left: cotton, Lycra (96/4) - Right: virgin wool, Lycra (96/4)  Wool with Lycra (4 %)
 PU shoe-soles  PU footbed  Polyurethane coated nylon
 Road marking  A two part polyurethane resin system applied as anti-slip to steps  Pedestrian crossings, symbols, stop lines
 Adhesives for PU running track  Tennis courts: acrylic and polyurethane textured colour coatings  Sports markings
 Indoor sports hall lining; exceptionally hard-wearing floor finish  Polyurethane cover  Walking (over water) in a thermoplastic PU ball
 Sound absorbing acoustical foams  Electric guitar: PU neck, middle, bridge  Polyurethane acoustic box
 Keyboard wiper  PU toys
 PU recoil air hose
 Meniscus: biodegradable polyurethane  Join together, stir shortly, ... foam  Thermoplastic polyurethane granules