Update matl_props README.md

PMMA/Material_Properties/README.md

@@ -25,4 +25,4 @@ A pyrolysis model validation exercise has been identified to validate the accura
 ### Recommended material property sets
 In March 2023, the UMD Pyrolysis model (material properties defined in MaCFP\_PMMA\_2021\UMD.json) was identified as the most 'central' or 'average' model of those currently available. That is, this model yields predictions closest (sum of square errors) to mean gasification predictions. It is suggested that this parameter set by used by modelers for initial model setup (to provide a common set of parameters for MaCFP PMMA). It is NOT implied to be the most accurate property set.
 
-In June 2023, [material property set(s) X] was/were identified as [the one / those] that most closely reproduce validation experiments of the [NIST-Gasification dataset](https://github.com/MaCFP/matl-db/tree/master/PMMA/Validation_Data). Provide further details in Table below; for each material property
+In June 2023, the UMD Pyrolysis model (material properties defined in MaCFP\_PMMA\_2021\UMD.json) was identified as the one that most closely reproduces validation experiments of the [NIST-Gasification dataset](https://github.com/MaCFP/matl-db/tree/master/PMMA/Validation_Data). Provide further details in Table below; for each material property