<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31373525</termId><termName>polytetrafluoroethylene</termName><termType>PT</termType><termNote><![CDATA[ Strong, tough, waxy, nonflammable synthetic resin produced by the polymerization of tetrafluoroethylene; has numerous applications. It is distinguished by its slippery surface, high melting point, and resistance to attack by almost all chemicals. ]]></termNote><termCreatedDate>2026-03-30 20:40:44</termCreatedDate><relation><relationType>UF</relationType><termId>31373526</termId><termName>PTFE</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31343235</termId><termName>polymers</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>31299325</termId><termName>Teflon (TM)</termName><termType>PT</termType></relation></term>  </Zthes>