# Evidence: polymer chain entanglement

Parent: — · class: solution behaviour · names merged here: polymer chain entanglement; polymer entanglement

2 papers measured or used it, 0 only mentioned it (of 207 kept papers). Papers in year order; each section heading ends with the paper's category / subcategory. Generated by tools/build_evidence.py from registry/concepts.csv and the cards; do not edit.

## 2023 Deac — Dissolution Mechanisms of Amorphous Solid Dispersions: A Close Look at the Dissolution Interface · Dissolution / A. Release mechanism and LoC

[2023-deac-asd-dissolution-interface](../../../cards/2023-deac-asd-dissolution-interface/paper.html) · Dissolution / A. Release mechanism and LoC · used · as: polymer entanglement

| id | kind | content | locator |
|---|---|---|---|
| C42 | claim, prior hypothesis, authors: asserted | Linear, nonionic, glassy polymers above the entanglement molecular weight, such as PVPVA, dissolve through a rubbery gel layer: solvent plasticizes the glass at the glass/gel interface; entangled chains there diffuse slowly while segments are mobile; the gel grows and swells as solvent enters and its viscosity falls; at a critical solvent concentration the chains disentangle and leave at the gel/solution interface [rests on: cited: refs 30-38] | p.2227-2228 |

## 2024 Deac — Dissolution mechanisms of amorphous solid dispersions: Role of polymer molecular weight and identification of a new failure mode · Dissolution / A. Release mechanism and LoC

[2024-deac-asd-polymer-molecular-weight-failure-mode-loc](../../../cards/2024-deac-asd-polymer-molecular-weight-failure-mode-loc/paper.html) · Dissolution / A. Release mechanism and LoC · used · as: polymer chain entanglement

| id | kind | content | locator |
|---|---|---|---|
| E1 | equation | critical molecular weight for chain entanglement (Wool): Mc ≈ 30 C∞ M0 | p.4 |
| E2 | equation | critical polymer concentration for entanglement (Graessley): ce = ρ Mc / Mw | p.4 |
| C16 | claim, conclusion, authors: "suggests" | An Mc of 46,620 g/mol means only K29/32, K60 and K90 have chains long enough to entangle; K90 can entangle at only 4% v/v, whereas K29/32 needs 80% v/v or more [rests on: M2-M7; E1, E2] | p.5 |
| C45 | claim, mechanism, authors: discussion: "gives support to the hypothesis", "may be contributing"; conclusion: "suggest" | The rise of the LoC near Mc supports the hypothesis that chain entanglement may contribute to droplet stabilization: entanglement raises viscosity sharply; water and drug molecules, much smaller than dT, diffuse as if unentangled, whereas droplets much larger than dT are held back (Fig. S8), like fish in a "fishnet"; droplets of a few hundred nm are too large for a mesh of at most 80 nm (K90 at ce); entangled high-MW chains stabilize the droplets against agglomeration by hindering their translational diffusion [rests on: R12, R5, R10, M5-M7, E3, E4; cited: refs 32-33, 48] | p.10 |
| C47 | claim, mechanism, authors: "are expected"; asserted ("explains") | K29/32 chains are expected to disentangle at a polymer volume fraction of 0.8 or below, which explains why no stabilization was seen in dilute solution; K12 chains are too short to entangle and form a "fishnet", so its droplets are prone to agglomeration [rests on: M5, M2, R5, R7, R10] | p.10 |