Nzira yekunzwisisa kukanganisa kwefluorine ndeyekuongorora mutsauko uripo pakati pemutsara we polyethylene (PE) ne PTFE inova ndiyo yekupedzisira fluoropolymer maererano nemidziyo uye maitiro.
Pane misiyano yakakosha pakati pezvivakwa zve PE neiyo yePTFE:
- * PTFE ndeimwe yepasi pasi pesimba mapolima
- *PTFE ndiyo inonyanya kupikisa polima
- *PTFE ndeimwe yeakanyanya kugadzikana mapolymers
- *Kunyunguduka uye kusimba kwePTFE kwakapetwa kaviri kune polyethylene
PTFE uye PE misiyano inokonzerwa nekusiyana kweCeF neCeH bond.Misiyano yezvinhu zvemagetsi uye saizi yeF uye H inotungamira kune zvinotevera zvinocherechedzwa:
- *F ndiyo inonyanya kushandisa magetsi pane zvese zvinhu (4 Paulings)
- *F ine maerekitironi maviri asina kugovaniswa
- *F inoshandurwa zviri nyore kuita Fe
- *Bond simba reCeF rakakwirira kudarika CeH
- *F ihombe pane H
Iyo electronegativity yekabhoni pa2.5 Paulings yakati wandei kupfuura yehydrogen uye yakaderera pane electronegativity yefluorine.Nekuda kweizvozvo, iyo polarity yechisungo cheCeF yakatarisana neiyo yeCeH bond, uye chisungo cheCeF chinowedzera polarized.Muchisungo cheCeF, magumo efluorine ebhondi anochajiswa zvisina kunaka zvichienzaniswa neCeH bond umo kabhoni inochajwa zvisina kunaka.
Musiyano mubhondi polarity yeCeH neCeF inokanganisa kugadzikana kwehukama hwemacheni maviri epolymer.Crystallization ye polyethylene inoitika mu planar uye trans conformation.PTFE inogona kumanikidzwa kupinda muchimiro chakadaro pakumanikidza kwakanyanya.PTFE, iri pasi pe 19 C, inopenya sehelix ine 0.169 nm pa kudzokorora chinhambwe: zvinotora 13 C maatomu kuti 180 kutendeuka kupedziswe.Pamusoro pe19 C, kureba kwekudzokorora kunowedzera kusvika pa 0.195 nm zvinoreva kuti maatomu ekabhoni gumi nemashanu anodiwa pakutendeuka kwe180.Pamusoro pe19 C maketani anokwanisa kusimuka, iyo inowedzera pamusoro pe30 C kusvika yasvika pakunyungudika (327 C).
Kutsiviwa kweF kune H muchisungo cheCeH kunowedzera simba rechisungo kubva pa99.5 kcal/mole yeCeH bond kusvika pa116 kcal/mole yeCeF bond.Nekuda kweizvozvo, kugadzikana kwekupisa uye kuramba kwemakemikari kwePTFE kwakakwira kupfuura PE nekuti simba rakawanda rinodiwa kutyora chisungo cheCeF.Iyo polarity uye kusimba kweiyo CeF bond inopa F atomu abstraction mechanism yebazi rakaoma.Kusiyana neizvi, polyethylene ine branched yakanyanya (>8 mapazi pa100 carbon atomu) inogona kugadzirwa.Branching mechanism sechishandiso chekugadzirisa crystallinity haishande kune PTFE.Panzvimbo iyoyo macomonomers ane pendent mapoka anofanirwa kuve nepolymerized neTFE.
Crystallinity ye PTFE isina kumbonyunguduka iri muhuwandu hwe92e98%, inopindirana neiyo isina kuvharwa ketani chimiro.FEP, copolymer yeTFE neHFP, ine se-polymerized crystallinity ye40e50%.MuFEP, iyo pedent CF3 boka rinosungirirwa kune tertiary kabhoni iyo isina kugadzikana zvishoma pane epuraimari neyechipiri kabhoni maatomu.Degradation curves inoratidza kuderera kwekutanga tembiricha ye300 C yeFEP (0.02% kuonda) uye 425 C yePTFE (0.03% kuonda).
Nguva yekutumira: Sep-25-2020