Rubber reinforcement of glassy polymers

Craze initiation in glassy polymers

In this work a method is presented that can be used to predict craze initiation in glassy polymers. The approach is based on the view that the development of a craze is preceded by de formation of a localised plastic deformation zone. As this zone develops, the hydrostatic stress increases, and, when exceeding a critical stress level, cavitation will take place, leading to local development of ...

Molecular dynamics simulations of glassy polymers

We review recent results from computer simulation studies of polymer glasses, from chain dynamics around glass transition temperature Tg to the mechanical behaviour below Tg. These results clearly show that modern computer simulations are able to address and give clear answers to some important issues in the field, in spite of the obvious limitations in terms of length and time scales. In the p...

Section-II: Nanocomposite polymers and elastomers- Processing and properties 2.7 Rubber and the concept of nano-reinforcement

Simple model for the deformation-induced relaxation of glassy polymers.

Glassy polymers show "strain hardening": at constant extensional load, their flow first accelerates, then arrests. Recent experiments have found this to be accompanied by a striking and unexplained dip in the segmental relaxation time. Here we explain such behavior by combining a minimal model of flow-induced liquefaction of a glass with a description of the stress carried by strained polymers,...

Direct evidence of two equilibration mechanisms in glassy polymers.

We investigated the kinetics of enthalpy recovery of several glass-forming polymers at temperatures significantly below the glass transition temperature (Tg) and for aging times up to one year. We find a double-step recovery at relatively low aging temperatures for the longest investigated aging times. The enthalpy recovered after the two-step decay approximately equals that expected by extrapo...