The data set is a study of photolysis and hydrolysis of poly(ethylene-terephthalate) films that contain an ultraviolet stabilizer additive. 
In this work, polymeric samples were exposed to UV light and moisture according to ASTM G-154 Cycle 4 standard accelerated weathering conditions. 
Resulting optical chemical changes were determined through optical and infrared (IR) spectroscopy. *Time* is the main exogenous variable and *YI* (yellowness index) is the endogenous variable (response). 
The other columns in the data set (*AbsEdge*, *UV.Stab.Bleaching*, *Crystallization*, and *ChainScission*) are values extracted from optical and IR absorbance spectra as single metrics and used as intermediate unit level endogenous (response) variables in the netSEM analysis.

datasets

The network structural equation modeling conducts a network
statistical analysis on a data frame of coincident observations of
multiple continuous variables [1].
It builds a pathway model by exploring a pool of domain knowledge guided
candidate statistical relationships between each of the variable pairs,
selecting the 'best fit' on the basis of a specific criteria such as
adjusted r-squared value.
This material is based upon work supported by the U.S. National Science
Foundation Award EEC-2052776 and EEC-2052662 for the MDS-Rely IUCRC Center,
under the NSF Solicitation:
NSF 20-570 Industry-University Cooperative Research Centers Program
[1] Bruckman, Laura S., Nicholas R. Wheeler, Junheng Ma, Ethan Wang,
Carl K. Wang, Ivan Chou, Jiayang Sun, and Roger H. French. (2013)
<doi:10.1109/ACCESS.2013.2267611>.

Laura Bruckman

netSEM

Network Structural Equation Modeling

Wei-Heng Huang

Nicholas R. Wheeler

Addison G. Klinke

Yifan Xu

Wenyu Du

Amit K. Verma

Abdulkerim Gok

Devin A. Gordon

Yu Wang

Sameera Nalin Venkat

HeinHtet Aung

Yeajin Jo

Xuanji Yu

Kemal Ozdemirli

Jonathan Gordon

Jayvic Cristian Jimenez

Jiqi Liu

Alan J. Curran

Justin S. Fada

Xuan Ma

Jennifer L. Braid

Jennifer L. W. Carter

Laura S. Bruckman

Roger H. French

pet function

A 37 by 6 data frame of continuous variables:<dl>
 <dt>YI</dt>
<dd>Yellowness index of PET film</dd> <dt>Time</dt>
<dd>Time exposed to ASTM G-154 Cycle 4 conditions</dd> <dt>AbsEdge</dt>
<dd>Fundamental Absorption Edge - Optical absorbance at 312 nm</dd> <dt>UVStabBleaching</dt>
<dd>Ultraviolet Stabilizer Bleaching - Optical absorbance at 340 nm</dd> <dt>Crystallization</dt>
<dd>IR spectropscopy peak of relative crystallinity - IR absorbance at 975 wavenumber</dd> <dt>ChainScission</dt>
<dd>IR carbonyl peak - IR absorbance at 1711 wavenumber</dd>
</dl>

Format

Devin A. Gordon, Wei-Heng Huang, Roger H. French, Laura S. Bruckman

Author

A data frame of an degradation experiment of poly(ethylene-terephthalate) films — pet

A 37 by 6 data frame of continuous variables:<dl>
 <dt>YI</dt>
<dd>Yellowness index of PET film</dd>

 <dt>Time</dt>
<dd>Time exposed to ASTM G-154 Cycle 4 conditions</dd>

 <dt>AbsEdge</dt>
<dd>Fundamental Absorption Edge - Optical absorbance at 312 nm</dd>

 <dt>UVStabBleaching</dt>
<dd>Ultraviolet Stabilizer Bleaching - Optical absorbance at 340 nm</dd>

 <dt>Crystallization</dt>
<dd>IR spectropscopy peak of relative crystallinity - IR absorbance at 975 wavenumber</dd>

 <dt>ChainScission</dt>
<dd>IR carbonyl peak - IR absorbance at 1711 wavenumber</dd>


</dl>

A data frame of an degradation experiment of poly(ethylene-terephthalate) films

pet: A data frame of an degradation experiment of poly(ethylene-terephthalate) films

Description

Usage

Arguments

Format

Author