Why does viscosity increase with molecular weight

This is why the strength and modulus are reduced for lower MW higher melt flow polymer. The world of polymers continues to grow and offers many design, cost and performance advantages to choose from. Let Amco help you today with our experience in selecting the right material for your application at a cost effective price. Read More. Get In Touch: Contact Us. What is Molecular weight? Molecular weight is the average weight of the molecules that make up a polymer and gives an indication of the length of the polymer chains The polymerization process is subject to variation so there is no single chain length, there is actually a wide range of lengths, so when we discuss molecular weight, we really mean the average molecular weight of the material.

Molecular weight and MWD or molecular weight distribution determine the polymers properties This table shows the effects of molecular weight on selected properties.

Table1 A High molecular weight increases how far the material can stretch before rupturing. The highest viscosity among the following is of. Dimensional formula of viscosity is. With the increasing molecular mass of a liquid, the viscosity. More Physics Questions Q1. In a convex lens, when the object is placed at infinity, where is the image formed? Which of the following is correct about sound? Large amplitude - Loud sound II. High frequency - Low pitch.

Which of the following happens due to atmospheric refraction? Twinkling of stars II. Advanced sunrise and delayed sunset. Supporting Information. Cited By. This article is cited by 3 publications. Calcium ions-effect on performance, growth and extracellular nature of microalgal-bacterial symbiosis system treating wastewater. Environmental Research , 96 , Coarse-grained simulations of ionic liquid materials: from monomeric ionic liquids to ionic liquid crystals and polymeric ionic liquids.

Physical Chemistry Chemical Physics , 23 35 , Dynamic mechanical thermal analysis of thermoset hydrogels. If you turn both cups upside down, the water drains much more quickly than the honey. This is because the molecular makeup of water gives it very little friction when it is in motion, while the molecular makeup of honey gives it a lot of internal friction. The internal friction from large molecules often results in congestion. Smaller molecules slide past each other more easily than larger molecules do.

Larger molecules also have stronger intermolecular forces, such as London Forces, which connect them to one another with greater power. This inhibits molecular flow, resulting in higher viscosity. As well as the size of the molecule, a substance's viscosity is affected by external force, which can be all types of actions, such as pushing, pulling, wiping or gravity.