Morphology Trajectory Governance
A doctrine establishing morphology trajectory as a governing constraint on durability, invalidating endpoint-only claims in trajectory-sensitive polymer regimes.
Thesis
Polymer durability under cyclic mechanical and environmental loading is governed not by static material properties or endpoint test outcomes, but by the explicit path taken through an observable, evolving morphology state space. In regimes where internal morphology evolves on service-relevant time and length scales, durability claims are structurally invalid unless the morphology trajectory itself is explicitly tracked, bounded, and shown to remain within validated limits.
This doctrine formalizes morphology trajectory as a first-class epistemic variable. It does not propose a new material, chemistry, or optimization pathway. It establishes a governance constraint that reality already enforces but qualification systems routinely ignore.
Scope and Applicability
Applies To
- Glassy amorphous polymers (e.g., polycarbonate, polystyrene)
- Semicrystalline thermoplastics (e.g., polyethylene, polypropylene, nylon)
- Supramolecular, multiphase, or physically crosslinked systems (ionomers, block copolymers, filled elastomers)
Does Not Apply To
- Inorganics or metallic glasses without functional morphology
- Fully crystalline polymers with no service-scale morphology evolution
- Chemistry-dominated degradation regimes where morphology is irrelevant (e.g., radiation-driven scission)
- Single-use, monotonic-load systems explicitly bounded as order-invariant
Outside these regimes, morphology trajectory governance is not triggered. Inside them, compliance is mandatory.
Minimal Observable Morphology Trajectory (MOMT)
Any durability, lifetime, fatigue, creep, or environmental resistance claim in a trajectory-sensitive regime must define and track a Minimal Observable Morphology Trajectory. This trajectory consists of at least three orthogonal, directly observable morphology parameters appropriate to the polymer family.
1. Glassy Amorphous Polymers
Acceptable observables (any three minimum):
- Free volume proxy (density, PALS, equivalent)
- Nanocraze or nanodefect density
- Residual stress field
- Physical aging index (enthalpy relaxation via DSC)
Acceptable trajectories are continuous and monotonic within characterized reversible ranges. Untracked relaxation or aging invalidates claims.
2. Semicrystalline Polymers
Acceptable observables (any three minimum):
- Degree of crystallinity
- Crystal domain size or distribution
- Amorphous phase fraction
- Tie-molecule density proxy
Morphology evolution must remain confined to predefined reversible annealing or aging pathways. Gradient collapse or uncharacterized recrystallization invalidates claims.
3. Supramolecular and Multiphase Systems
Acceptable observables (any three minimum):
- Domain size distribution
- Phase connectivity or percolation state
- Interfacial curvature or tension proxy
- Interfacial cohesion proxy
Domain evolution must be reversible under prescribed cycling. Unidirectional coarsening, percolation archiving, or interface degradation constitutes irreversible trajectory failure.
Trajectory Continuity Requirement
Durability claims must reference a continuous morphology trajectory, not merely initial and final states. Missing intervals, interpolated assumptions, or endpoint-only snapshots constitute a structural trajectory break and invalidate the claim.
Non-Commutativity Declaration
When both mechanical and environmental loads apply, claims must either demonstrate order invariance or explicitly test non-commutative load sequences (e.g., environment-then-mechanics versus mechanics-then-environment). Silence on order effects is treated as non-compliance.
Irreversible Loss of Claim Eligibility
A system irreversibly loses claim eligibility if any monitored morphology parameter:
- Crosses a characterized non-recoverable threshold
- Exhibits path-dependent drift that cannot be reset by permitted processes
- No longer maps to any validated morphology state correlated with performance
Once violated, prior certifications are void. Reuse, equivalence, or extension claims are forbidden without full requalification.
Falsifiability Requirement
Every claim must include at least one explicit kill condition—an observable morphology threshold beyond which the claim fails. Claims without falsifiability conditions are non-scientific and invalid under this doctrine.
Why This Doctrine Exists
The physical quantity systematically excluded from polymer durability qualification is the evolving, spatially heterogeneous distribution of internal configurational energy states—free volume, entanglement stress, interfacial cohesion, and defect populations—and its irreversible redistribution under coupled load and environment.
Endpoint tests collapse this field into scalar averages, masking the trajectory that actually governs failure. This doctrine does not add a new variable; it forces explicit accounting for a quantity that has always controlled outcome but has never been governed.
Edge of Knowledge Judgment
GO. This doctrine is structurally complete, falsifiable, and regime-bounded. It does not claim predictive universality, nor does it prescribe material solutions. It elevates the epistemic standard required to honestly assert durability in systems where morphology evolves.
Edge of Knowledge documents are updated only by explicit revision and remain accessible for epistemic continuity.