Umbhakha Wemolekyuli Yopolikhabhonethi: Kungani Kukhulu Nezikhuthaza

Isahluko Esingaphandle SeMolekyuli: Indlela U-Bisphenol A Nase-Carbonate Linkages Kuyenzela Ubunzima

U-Bisphenol A Nase-Carbonate Linkages Kwenza Umbuthano Othintekayo, Othembulukileyo

Amandla ka-polycarbonate ayiseleni kwezinhlayiya zalo. Xa i-Bisphenol A ihlangana, iyengeza izinkinga ezimbili zezinhlayiya eziphambene ngokuphelele. Ngakwesikhathi esifanayo, izigaba ze-carbonate zihlukanisa lezi zinqumo kuze kube yizinhlayiya ezinde. Okuthola kithi kukhona ukulungiswa okuhle lapho izimodi zihlanganisa ngaphakathi kahle. Isiphumo? Ukukhathala okuphezulu kumandla ekugcineni uma kugcinwa ukuthi angalilale kusona ngaphandle kokugcinwa. Lokhu kamenza amandla ka-polycarbonate aphinde angeze ubukhulu bokugcina ngaphezu kuka-70 MPa futhi akhombise ukuphephelwa kwangaphandle nokugcinwa. Okunye okubalulekile ngemeko ye-aromatic rings kukuthi kujabulisa umshimba wokucopheleka ngokushisa kwe-electron phakathi kwezinhlayiya zalo. Lokhu kusiza ekukhomeni ukulahlekelwa ngokuphakade xa izinto zingcinwa yizimo ezihlukahlukene.

Ukugcinwa Kwezinhlayiya Ne-Temperature Ephezulu Yokuguquguquka Kwamaglas (Tg ≈ 145°C)

Umbuthano wesithelo sendawo yokuba ngu-polycarbonate kusinxa kakhulu umthwalo wokuphefumula. Xa sibuka indlela ama-polimeri avaleka, kudinga amandla angaphezu kwezinye ukushiywa kweziphazamiso zomtshana neziphazamiso zomtshana. Ngakho-ke i-polycarbonate inemiphefumulo ephezulu yeglasasi, ngaphezu kwamadebesi angama-145. Ama-thermoplastics angaphandle kwalokhu ayeka ukuba asiphazene xa ifinyelela iphuzu laTg, kodwa i-polycarbonate isilapha ngesikhathi esizayo sezigaba ezingu-85% ezigcwele xa kuyi-100°C ngoba amakhaini asezipolimini aqhubeka entangeni. Lokhu okunikeza izidingo zokuphefumula kwenza i-polycarbonate ibalulekile kakhulu kizinto apho ubukhona bezinkinga kakhulu. Cabanga ngamaphakethe ethu engeyiyo emanzini aphefumulayo okanye indlu yezixhobo zedijithali ezilungisa umthwalo ngexesha lokusebenza. Isenzo sisesinquma ngaphandle kokuchithwa phantsi kwezimo eziphumelelayo.

Ukuzivikela Kuhlaziywa: Indlela Yokuhamba Kwemolekiyu Nezindlela Zokulahla Amakhanda

Ukugayaya Kwesheya vs. Ukudala Kwezikhethi: Indima Yokuqhakazeka Kwegubungu Kuqiniso

Yini eyenzela ukuthi ikhabonathi eziphazinyawo ibe yiqiniso ngokwesivivane? Lomthelela unezindlela ezimbili zokuphatha ubuchwepheshe: ukugayaya kwe-sheya nokudala kwezikhethi. Xa kunjalo okuthile kuyiphindaphinda, izigaba ezinde zamapolimera ziyagulwa futhi zihambe ngendlela yokugayaya. Ngasinye isikhathi, amavoyidi amancane ayidala emaphakathini amanelisa, apho akhokelelwa ngezihluzi ezincane ezakhiwa ngendlela ethile. Le ndlela iyamukela izikhalo ukuthi zingaphinde. Undima olusebenza khona kungukuthi kukhona okuningi kwalawa mazigaba atholakala edonsa. Zisebenza njengalezi zibambazane ezincane emahlathini, zenza ukuthembeka futhi zizide kakhulu xaxa zilungelela ngokwesivivane. Ngaleso sikhathi, ikhabonathi eziphazinyawo ingalima kakhulu — ngaphezu kuka-30 foot pounds per inch kabefore ekhubazeka. Lokhu kuyenzela ukuthi ibe phambili kakhulu kunye nezinhlangothi eziningi uma kufika lapho kudingeka ukulindela kusiva.

Ukugcizeleza Kwedatha: I-Polycarbonate ibamba imishimba yokuqina kancane ngaphezulu kuka-Acrylic (ISO 180/1A)

Ukuhlaziywa kwe-impact kwe-ISO 180/1A okwamandla kuvikela lolona gqugqa:

• I-Polycarbonate ibamba 65 kJ/m²
• I-Acrylic (PMMA) ibamba kuphela 32 kJ/m²
  Lolu phindaphindo oluncane kakhulu lweshumi nesithupha lukhombisa ukuthi ukuxhumana kwegunya le-molecular kwe-polycarbonate kuyenzela ukuthi kube yini elinamandla okungaphezulu. Amagunya e-carbonate asebenza njengama-hinges ayahambelana ngenkathi kusetyenziswa umshimba, ngelixa amagunya asebenzela i-bisphenol-A aphinde aphathe ubunzima—kuyivumela ukuthi ikhuluke kakhulu ngaphambi kokuhlukunyezeka, ngasemva kwalokho akunjalo ne-acrylics ethintangalala.

Imithwalo Yobulindelelako: Ubunzima BekuHluko KukaNtshilo NeSensitivity YeChemical YeCarbonate Groups

Amakhonkco Amandla Akarboneti Ngaphandle Kwesensitivity Ye-Acid/Base: Ubuqhakazi BeStability

Amakhonkco e-carbonate atholakala kwi-polymers eziningi (lezo ziklango -O-(C=O)-O-) azinika izinto amakhonkco abalulekile okuhlanjulwa kwezibonelo ngamanzi, okwenzela ukuthi asebenze kahle noma kube mthwana. Kodwa kukhona into. Lezi zikhonkco njalo zihlanjulwa kancane uma ziyatholakala phambi kwemithwako noma imithwako. Kuzindlela ezimbi, i-protons ziqhakamisa kumaziphiwo, ngelixa i-hydroxide ions ezifakwa kumaziphiwo ahlanzekile ayiziphatha futhi ayizihlanjulise. Izivivinyo zebhulosekile zibonisa ukuthi emva kokuhlala kusayensi enegama le-pH 3 ngaphezu kweminyaka engu-20, ubude bezintsho zezinto buphansi ngama-15%. Lokhu okubili kusho ukuthi abasebenzi kumele bachinge kahle ngaphi kumele ba sebenzise i-polycarbonate. Ishiyi kahle kumakilini akudingekayo, kodwa uma lezi ziphawu ziyophakama nezinkundla ezibi, abayikreleli kumele bazithuthuze ngendlela yokukhuselela noma babuyekelele izinto.

Ikhanda Lelwandle Nenkcubeko Yomthombo: Isabelo Sakho Kusikhathiwa Kwemodi

Usayidi Lokulungiswa KweKhanda Lelwandle (Mw/Mn ≈ 2.0−3.5) Nezizathu Zokuphikiswa KweIzod

Iziphawu zomthwalo zomthwalo zihlobene kakhulu nokuthi imolayile yazo yagcwele kanjani kanti nebuso obukhulu kwezinhlongo zomphakathi. Xa kufika ekuphathelweni kwezinhlongo, sithola ukuthi izimbono ezenza izilinganiso zika Mw/Mn ekuhamba phakathi kuka-2.0 kuya kuka-3.5 zenza ngokubanzi kakhulu okuthile kubukhuni bokuhlangana okukhomba ukuthi kuthintelwe ngokuthile. Uma sibuka iziphumo zomshado, ubunzima bokugaya kwe-Izod ebekwe kweza kakhulu njengoba ubungozi bwe-molecular buhamba phambili. Izinhlongo ezinde kune-30,000 grams per mole zingasebenzisa amandla angama-60% ngaphezulu kabefore ekugayeni kusuka kwezinye ezingaphansi kanti amaphethini angasephinde aphinde ayehlise ngendlela ebalulekile. Lokhu kugcina okubanzi nokuthando kwenza ukuthi lezi zimbono zibe yisidingo esibalulekile kizinto apho ubuhle buhle bakhona, njengoko kwezinkomo ezingaphansi kwabasebenzi basekhaya noma iziqhamo zasekhaya ezingaphansi kwemoto ezingadinga ukuthutha izinkinga ngaphandle kokuthi zihlise ngendlela ebalulekile.

Kusukela eMithethweni yeMolecular kuze kufinyelele kwezimali: Ukukhula ngokusebenza

Ukwakheka kwamangqamuzana e-polycarbonate, kuhlanganise nesakhiwo sayo esiqinile, ukuhlangana okukhulu kwamaketanga, kanye nokuxhumeka okuqinile kwe-carbonate, kudlala indima ebalulekile ekwakheni izinto ezisebenza kahle. Onjiniyela abaningi bathola ukubaluleka ekushiseni kwengilazi yayo okungama - 145 degrees Celsius lapho beklama izingxenye ezifakwa ngaphakathi kwezinjini zezimoto. Bayawazisa futhi amandla aleli thuluzi okumelana nokushayisana, okwenza kube kuhle ukuba asetshenziswe ezintweni ezinjengamathuluzi okuvikela izibhelu abonakalayo nezigqoko zezingcingo ezingasindi lapho ziwela. Abakhiqizi bemishini yezokwelapha bathembela ekutheni i-polycarbonate ayinakugqashuka emanzini lapho isetshenziswa ezintweni ezidinga ukuhlanzwa njalo. Ngama-computer anamuhla, abacwaningi manje sebekwazi ukubikezela ukuthi izinguquko ezenzeka emaceleni esisindo samangqamuzana noma ezakhiweni ezihlukahlukene zamaketanga ziyozithinta kanjani izakhiwo ezinjengamandla omthelela we-Notched Izod. Lolu khono lokubona kusengaphambili lusiza ekwakheni izinhlobo ezikhethekile ezenzelwe izinhlelo ezithile zokusebenza ezisukela emathangeni ezindiza alula kwezobunjiniyela bezemishini yezindiza kuya ezingxenyeni zezokwelapha ezihambisana nemvelo ezizinzile ngaphansi kwemisebe ye-gamma, kuze kufike kulezo z

Imibuzo Evame Ukubuzwa

Kungani ukukhulisa kuka-polycarbonate kuyinkimbinkimbi?

Ukukhulisa kuka-polycarbonate kukhulwe kumqondo walo othemba, ngokuthaka ukudibanwa kuka-Bisphenol A nasekugqibeleni kuka-carbonate, okwakha umgodi othintela obukeka okuphathelene nokukhathazeka kwamandla.

Kungani ukuthelekelwa kuka-polycarbonate kuyakhanyayo?

U-Polycarbonate unemali ephakeme yokutheleka (ngaphezu kuka-145°C), lokhu kumvumela ukuba akhombise ukuthintela nokuthintela phakade emaqondana aphakeme, kuyidinga konke okumele kusebenzi lapho ukuthintela kuyadingeka.

Ukuthi polycarbonate kulinganiswa ne-acrylic ngokusho komthelelo wokungena kanjani?

U-polycarbonate uphinde uphinde amandla wokungena ngaphezulu kunye ne-acrylic, izidingo ezivame zibonisa ukuthi uphinde amandla ka-65 kJ/m² ngaphandle kuka-acrylic okuphinde kwa-32 kJ/m², ngokunjalo nomqondo walo othintela namaningi akawanda kagqoka.

Iziprojelo ziphi eziphakamileyo eziphakathi kuka-polycarbonate ngokuxhaswa kuchemikhosi?

Nakuba ikhanda le-polycarbonate litholakala ngamakhemikhali ezigqithelene ngokukhanya athola ubunzima bamanzi, kungahle kuhluleka ekugcineni kwe-acids noma kwebases, kudinga izindlela zokulungiselela emkhathini olunzima kakhulu.

Ukubanzi kwe-molecular kuthinta kanjani izici zomthwalo we-polycarbonate?

Ukubanzi okuphakade kwe-molecular kuthuthukisa izici zomthwalo we-polycarbonate ngokuthuthukisa ubukhawulezi bomthwalo wokugqithwa, okusiza ekunikelweni kwe-energi ngemva kokugcina.