Inqubo yokukhiqiza ipulasitiki ye-polyether ether ketone (PEEK) kanye nokusetshenziswa kwayo embonini yezindiza
I-Polyether ether ketone (PEEK) iyipulasitiki yobunjiniyela esebenza kahle kakhulu esetshenziswa kakhulu lapho izinto kufanele zihlale ziqinile, zizinzile, futhi zingashisi ngaphansi kwezimo ezimbi kakhulu. Embonini yezindiza, i-PEEK idonsele ukunaka ngoba ingathatha indawo yensimbi kancane kwezinye izingxenye, ngenkathi inikeza izinzuzo ezifana nesisindo esilula, ukumelana namakhemikhali aphezulu, kanye nokumelana nokukhathala nokuguguleka. Lesi sihloko sixoxa ngenqubo yokukhiqiza i-PEEK ngombono wamakhemikhali-polymer, izigaba zayo zezimboni, kanye nendlela le nto esetshenziswa ngayo emhlabeni wezindiza.
Ukubheka i-PEEK kanye nezici zayo
I-PEEK ingeyomndeni wama-polymer aromatic aromatic aromatic aromatic. Isakhiwo sayo seketanga siqukethe amaqembu e-ether (-O-) kanye ne-ketone (-CO-) ahlelwe ezindandatho ze-aromatic. Lokhu kuhlanganiswa kuphumela ezicini eziqinile zemishini kanye nokuqina okuphezulu kokushisa. Ngokuvamile, i-PEEK yaziwa ngephuzu layo eliphezulu lokuncibilika (cishe ama-343°C), ukumelana nokushisa isikhathi eside okuhle kakhulu, kanye nokumelana nezinyibilikisi eziningi kanye namakhemikhali anamandla. Ngaphezu kwalokho, i-PEEK imelana nemisebe futhi ingakhiwa ukuze ihlangabezane nezidingo zokuphepha ezifana nokumelana nomlilo, intuthu, kanye nobuthi (FST), okubalulekile ezindlini zezindiza.
Lezi zakhiwo ezinhle kakhulu zenza i-PEEK ibe "yi-thermoplastic esebenza kahle kakhulu." Ngokungafani nama-thermosets, lapho uma eseqinisiwe kunzima ukuwasebenzisa kabusha, i-PEEK, njenge-thermoplastic, ingacutshungulwa kabusha ngokushisa, inikeze ukuguquguquka kokukhiqiza (isb., umjovo, i-extrusion, i-compression, noma ezinye izinhlelo zokusebenza zokuphrinta ze-3D), yize idinga imishini ekwaziyo ukuphatha amazinga okushisa aphezulu.
Izinto zokusetshenziswa kanye nezimiso zokusabela ekwakhiweni kwe-PEEK
Kwezimboni, i-PEEK ikhiqizwa nge-step-growth polymerization ehilela ama-monomers asebenzayo e-aromatic. Enye indlela yokwenziwa eyaziwa kabanzi ihilela ukusabela kwama-dihalides aromatic nama-bisphenolate salts kuma-solvents e-polar aprotic emazingeni okushisa aphezulu. Ngomqondo, ukwakheka kwe-ether bond kwenzeka ngokufakwa esikhundleni kwe-nucleophilic aromatic (SNAr), okusebenza kahle kuma-rings e-aromatic anamaqembu ahle okukhipha ama-electron nokuphuma.
Emisebenzini yezimboni, ukukhethwa kwe-monomer, uhlobo lwesisekelo, ukukhethwa kwe-solvent, kanye nokulawulwa kobumsulwa kuthonya kakhulu isisindo sama-molecule se-polymer, ukusatshalaliswa kwesisindo sama-molecule, umbala, kanye nokusebenza kokugcina. Ngenxa yokuthi i-PEEK ihloselwe ukusetshenziswa okubalulekile (kufaka phakathi i-aerospace), amazinga okungcola kwe-ionic, umswakama, kanye nezinsalela ze-solvent kumele alawulwe ngokuqinile.
Izigaba zenqubo yokukhiqiza ye-PEEK yezimboni
Nakuba umenzi ngamunye engase abe nokwehluka kwezinqubo zakhe ezivikelwe kanye nezindlela zokupheka, inqubo yokukhiqiza ye-PEEK ejwayelekile ingafingqwa ngezinyathelo ezilandelayo.
1) Ukulungiswa nokuhlanzwa kwezinto zokusetshenziswa
Izinyathelo zokuqala zifaka phakathi ukomisa i-monomer kanye ne-solvent, kanye nokuhlanza ukuze kususwe ukungcola okufana namanzi, ama-ion ensimbi, noma ama-compound angamisa ukukhula kweketanga (ama-chain terminators). Amanzi ayisitha esiyinhloko ezinqubweni eziningi ze-condensation polymerization ngoba angashintsha ukusabela futhi athinte isisindo sama-molecule somkhiqizo. Ngakho-ke, uhlelo luvame ukugcinwa lomile kakhulu, okuhlanganisa nokusetshenziswa kwegesi engangenisi umswakama ukuze kufakwe ingubo.
2) Ukwakheka kosawoti we-bisphenolate (ukusebenza kwe-nucleophile)
Ama-monomer e-phenolic ngokuvamile aguqulwa abe amafomu awo kasawoti kusetshenziswa isisekelo (isb., i-carbonate). Umgomo ukukhiqiza i-nucleophile enamandla (i-phenolate) ehlasela kalula i-monomer e-aromatic ene-halogenated. Lesi sinyathelo sidinga nokulawulwa okuqondile kwe-stoichiometric, njengoba ukungalingani kwesilinganiso sokusebenza kunganciphisa izinga le-polymerization futhi kuthinte izakhiwo zemishini.
3) Ukusabela kwe-polymerization ekushiseni okuphezulu
Ukusabela okuyinhloko kwenzeka emazingeni okushisa aphezulu ku-reactor engagqwali ekwazi ukuxubana okuphezulu. Izithako ze-polar aprotic solvents zisiza ekuncibilikiseni izinhlobo ezisabelayo kusenesikhathi, okuvumela ukusabela ukuthi kuqhubeke kahle. Njengoba uchungechunge lwe-polymer lukhula, i-viscosity iyanda kakhulu, futhi ukulawulwa kokushisa kuba kubaluleke kakhulu ukuvimbela izindawo ezishisayo noma ukuwohloka kokushisa.
Kulesi sigaba, amapharamitha enqubo afana nokushisa, isikhathi sokuhlala, kanye nesilinganiso sokuxuba kuthinta isisindo sama-molecule. Abakhiqizi bavame ukugxila kububanzi obuthile be-melt viscosity ngoba buhambisana nokulula kokucutshungulwa okulandelayo (isb., i-extrusion) kanye nokusebenza kokugcina.
4) Ukuqeda, ukupholisa, kanye nokususwa kwenhlabathi (ukuhlukaniswa)
Ngemva kokufinyelela izinga eliqondiwe le-polymerization, ukusabela kuyamiswa bese ingxube ipholiswa. I-polymer ibe isihlukaniswa, ngokuvamile ngemvula ibe yindawo engeyona eye-solvent noma ngesinyathelo esithile sokuhlukanisa. Umgomo ukuhlukanisa i-PEEK ku-solvent, usawoti ongaphili, kanye nezinsalela zokusabela.
5) Ukugeza nokomisa
I-polymer ehlukanisiwe igezwa ngokuphindaphindiwe ukuze kuncishiswe okuqukethwe yi-ionic kanye nezinsalela ze-solvent. Isigaba sokomisa senziwa ngaphansi kwezimo eziqinisekisa umswakama ophansi kakhulu. Ekusetshenzisweni kwezindiza, ukulawulwa kokuguquguquka nokungcola kubalulekile njengoba kungathinta ukuphuma kwegesi, ikhwalithi yobuso, kanye nokuqina kwesikhathi eside.
6) Ukuhlanganisa: ukwengeza izithasiselo kanye nokuqinisa
I-PEEK emsulwa isivele inamandla kakhulu, kodwa ezinhlotsheni eziningi ithuthukiswa ngama-filler/reinforcers afana ne-carbon fiber, i-fiberglass, noma i-PTFE ukuze kwehliswe i-coefficient of friction futhi kwandiswe ukumelana nokuguguleka. Ukuhlanganisa kwenziwa kusetshenziswa i-extruder yokushisa okuphezulu. Ukwakheka kokuqinisa kumele kuhambisane, ukuhlakazeka kufane, kanye nobude be-fiber bugcinwe ukuze kufezwe izakhiwo zemishini ezifunwayo.
7) Ukulawula i-pelletization kanye nekhwalithi
Umkhiqizo wokugcina uvame ukwenziwa ngesimo se-pellet ukuze kube lula ukuqhubeka nokucutshungulwa. Ukulawulwa kwekhwalithi kuhlanganisa ukulinganiswa kwe-viscosity, ukuhlaziywa kokuqukethwe komlotha (kwama-filler), i-DSC yokwakheka kwekristalu kanye nendawo yokuncibilika, i-TGA yokuqina kokushisa, ukuhlolwa komshini (ukuqina, ukuguquguquka, umthelela), kanye nokuhlolwa kwe-FST uma kuhloswe ngaphakathi kwendiza.
Ukucubungula i-PEEK kube izingxenye
Ekukhiqizweni kwezingxenye, i-PEEK ingacutshungulwa yi:
– Ukubumba ngomjovo wezingxenye eziyinkimbinkimbi kudinga isikhunta nemishini ekwazi ukumelana nokushisa okuphezulu.
– Ukukhipha ukuze kudalwe amaphrofayili, amapayipi, amafilimu, noma izimo eziqediwe kancane.
– Ukubumba kokucindezela kwamashidi noma izimo ezithile.
– Umshini wenduku/ipuleti le-PEEK eliqediwe kancane ukuze livumelane kahle.
– Ukukhiqiza okuthile okungeziwe (isib. i-FFF/FGF yezinga lezimboni) okudinga ukulawulwa kokushisa okuphezulu kwegumbi lokuphrinta ukuze kuncishiswe ukugoba kanye nokwehlukaniswa.
Ngenxa yokuthi i-PEEK iyi-semicrystalline, izinga lokupholisa lithinta ubukristalu, okugcina kuthinta ukuqina, ukumelana namakhemikhali, kanye nokuqina kobukhulu. Ukulawulwa kokushisa kwesikhunta kanye nokufakwa ngemuva kokufakwa kuvame ukusetshenziselwa ukufeza izakhiwo ezinhle kakhulu.
Izinhlelo zokusebenza ze-PEEK embonini yezindiza
Emkhathini, izinto zikhethwa ngokusekelwe esilinganisweni sazo samandla nesisindo, ukumelana nokushisa, ukumelana nomlilo, ukumelana noketshezi, kanye nokuthembeka kwesikhathi eside. I-PEEK ihlangabezana neziningi zalezi zindlela, ikakhulukazi emabangeni ahlanganisiwe noma okukhethekile.
1) Izingxenye zesakhiwo ezilula kanye nama-bracket
I-PEEK (ikakhulukazi i-carbon fiber-reinforced) isetshenziselwa ama-bracket, ama-clamp, kanye nezingxenye zokusekela ezenziwe nge-aluminium noma insimbi ezindaweni ezithile. Izinzuzo zayo eziyinhloko ukunciphisa isisindo, ukumelana nokugqwala, kanye nokuqina phakathi nomjikelezo wokushisa.
2) Uhlelo lwekhebula, izixhumi kanye nokufakwa kokushisa
I-PEEK isetshenziswa kabanzi kuma-insulator, izixhumi, kanye ne-cable sheathing ngenxa yokuqina kwayo kwe-dielectric kanye nokumelana nokushisa. Ezindizeni zesimanje, ezisebenzisa ugesi owandayo, isidingo sezinto zokuvikela ezisebenza kahle siyaqhubeka nokukhula.
3) Amabheringi, ama-bushing, kanye nezingxenye ze-tribological
Amazinga e-PEEK aguqulwe nge-PTFE/carbon fiber avame ukusetshenziswa kuma-bushings, ama-washer, nezinye izingxenye zokungqubuzana. Lezi zinto zinikeza ukumelana okuhle nokuguguleka, i-coefficient ephansi yokungqubuzana, kanye nokusebenza okuzinzile ezindaweni ezithile zamakhemikhali.
4) Izidingo zangaphakathi kwezindiza kanye ne-FST
Kwangaphakathi, izindinganiso ze-FST (ilangabi, umusi, ubuthi) ziqinile kakhulu. I-PEEK ingakhiwa ukuze ihlangabezane nalezi zidingo, okwenza ifanelekele ukusetshenziswa okuhlukahlukene kwangaphakathi, kufaka phakathi izingxenye ezidinga ukumelana nokushisa kanye namandla omshini ngaphandle kokwengeza isisindo esiningi.
5) Izinhlanganisela ze-thermoplastic zezakhiwo
Umkhuba owodwa omkhulu ukusetshenziswa kwe-carbon fiber matrix composites ene-PEEK (Carbon Fiber Reinforced PEEK/CFR-PEEK). Uma kuqhathaniswa nama-thermosets, ama-thermoplastic composites anikeza amandla okushisela okushisa, imijikelezo yokukhiqiza esheshayo, kanye nokumelana okuhle komthelela. Esimweni sezindiza, lokhu kuyathandeka kumaphaneli, ama-stiffeners, kanye nezingxenye ezithile ezidinga inhlanganisela yokuqina kanye namakhono okukhiqiza asebenza kahle.
Izinselele kanye nokucatshangelwa kokusebenzisa i-PEEK ezindiza
Naphezu kwezinzuzo zayo, i-PEEK ibhekene nezinselele eziningana. Okokuqala, izindleko zezinto zokwakha kanye nokucubungula ziphakeme kakhulu ngenxa yokushisa okuphezulu kokucubungula kanye nezidingo zokulawula ikhwalithi eqinile. Okwesibili, ukwakheka kwezingxenye kumele kucabangele i-composite anisotropy kanye nezinguquko ezakhiweni ngenxa yokuqondiswa kwefayibha noma izimo zokupholisa. Okwesithathu, ngezicelo eziqinisekisiwe, izinto zokwakha kanye nenqubo kumele kudlule uchungechunge olude lokuhlolwa kanye nemibhalo.
I-Penutup
I-PEEK iyipulasitiki yobunjiniyela esezingeni eliphezulu enenhlanganisela eyingqayizivele yamandla, ukumelana nokushisa, ukumelana namakhemikhali, kanye nekhono lokucubungula njenge-thermoplastic. Inqubo yayo yokukhiqiza ihilela i-polymerization yokushisa okuphezulu ngokulawula okuqinile ubumsulwa, i-stoichiometry, kanye nokushisa komkhiqizo. Uma isifakwe i-pellet kanye/noma ihlanganisiwe, i-PEEK ingakhiwa ibe yizingxenye ngokufaka i-injection molding, i-extrusion, i-machining, noma njenge-carbon fiber matrix composite. Embonini yezindiza, i-PEEK isetshenziselwa ukunciphisa isisindo, ukuthuthukisa ukumelana nokugqwala, kanye nokuhlangabezana nezidingo zokusebenza kanye nokuphepha, kusukela kuma-bracket kanye nama-insulator kuya kuma-bearings kanye nama-thermoplastic composites aqinile. Njengoba kuthambekele endizeni esebenza kahle kakhulu kanye nokwanda kokufakwa kukagesi, indima ye-PEEK kanye nomndeni wayo wama-thermoplastics asebenza kahle kulindeleke ukuthi iqhubeke nokukhula.
Uma ufisa, ngingavumelanisa lesi sihloko nesitayela sephepha lesayensi (ngezinkomba kanye nohlu lwezincwadi), noma ngengeze izingxenye ezikhethekile ezifana namapharamitha enqubo (ububanzi bokushisa, ukulawulwa kwekristalu), izifundo zamacala zezinhlelo zokusebenza ezihlanganisiwe ze-CFR-PEEK, noma ukuqhathanisa i-PEEK ne-PEI, i-PPS, kanye ne-PTFE kwezinhlelo zokusebenza zezindiza.
