采用捕获聚合法来制备长序定义的聚合物

Unlike small molecules with definite molecular weights, polymers are a mixture of individual polymer chains of varying lengths, each with a unique molecular weight.  So, the molecular weight of a polymer is expressed as an average value based on the average size of the polymer chains. The two most common forms of averages used for polymers are the number average molecular weight and weight average molecular weight.
The number average molecular weight (Mn) is the summation of the number...

The word polymer is derived from the Greek words “poly” which means “many” and “mer” which means “parts”. Polymers are long chains of molecules composed of repeating units of smaller molecules, known as monomers. They either occur naturally, such as DNA and proteins, or can be constructed synthetically, like plastics. They have varied structural characteristics, such as linear chains, branched chains, or complex networks, that contribute to the...

Psychology is the scientific discipline dedicated to understanding both observable behavior and the internal mental processes underlying such behavior. It aims to comprehend human nature and apply this understanding to solve practical problems, enhance well-being, and improve societal outcomes. An example of psychology's application is the study of prosocial behavior, such as why and under what conditions individuals might help strangers in need. This process involves describing observed...

Ring-opening metathesis polymerization or ROMP involves strained cycloalkenes as starting materials. The mechanism of ROMP proceeds by reacting cycloalkene with Grubbs catalyst to give metallacyclobutane intermediate which undergoes a ring-opening reaction to form new carbene. The new carbene reacts with another molecule of cycloalkene. Repetition of these steps leads to the formation of an unsaturated open-chain polymer product. All these steps are reversible, however, relieving the ring...

Social psychology investigates how the presence and actions of others influence individual behavior, cognition, and emotion. Examining the social environment's impact provides a scientific framework for understanding how individuals perceive others and are, in turn, influenced by them. This field seeks to uncover the underlying principles guiding social interactions, exploring phenomena such as conformity, obedience, and prosocial behavior.Core Themes in Social PsychologyOne central focus of...