As a consequence of this phenomenon, the two polymers are provided with a rougher and extended interface where the macromolecules can interdiffuse
. This observation is supported by the micro-CT scans shown in Fig.
The compounds with relatively higher stiffness such as sample TP2 have indicated inferior tack strength (see Figure 3(b)), which is related to the inability of the rubber molecules to flow or interdiffuse
across the interface.
Presumably, dangling ends of crosslinked molecules and any uncrosslinked molecules present are able to interdiffuse
. But how much internal crosslinking can be tolerated before interdiffusion is impeded sufficiently that the film cannot approach the mechanical film properties of uniformly crosslinked latex of that composition?
This distinctive scattering characteristic allows researchers to highlight specific groups in complex molecules by selective deuteration and leads to major advances in our understanding of structures that occur, for example when viruses attack membranes, or when polymer layers interdiffuse
Investigations on injection molded double-gated tensile bars have shown that weld-line strength is most readily improved by increasing the melt temperature[(1-4)] This is reasonable from a molecular level; as the temperature increases, the polymer chains will interdiffuse
This increase in adhesion with annealing time has been reported previously for PE-PP interfaces  and blends  and is attributed to the thermodynamical motion of the polymer chains, which allows them to interdiffuse
through the interface and entangle with each other.
Furthermore, the pullout features are more prominent and some of them bridge bunches of latex particles, indicating that many of these latex particles had begun to interdiffuse
and progressed further toward coalescence between hour six and hour twelve.
The two resins can interdiffuse
before gelling [4, 5].
This is because molecular interdiffusion between neighboring particles, which is essential for the generation of latex film strength, (33-35) must take place prior to the crosslinking reaction (7), (11), (30-32) Strongly crosslinked particles are unable to interdiffuse
. (24-29) In systems having an external crosslinker that is dissolved in the aqueous phase, its partitioning character between the polymer and water imparts a further complication.
Then as heating constantly, the temperature at interface reaches above melting point ([T.sub.m]), the materials soften and melt so that chains become free and can interdiffuse
across the weld interface in terms of Fig.
We have learned that the slightly branched polystyrene chains can interdiffuse
across the particle-particle junctions during the film formation process.
The strength of the joint is a result of the interpenetration of polymer chains across an interface and develops as increasing amounts of polymer interdiffuse
. It is influenced by factors such as molecular weight, the distribution of polymer chains within the specimen, induced orientation within a polymer, chemical dissimilarity, chain architecture and crystallization.