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Intshayelelo: Indima yeZithako zeSilicone kwiNkqubo yePolymer
Izongezo zesilicone zisetyenziswa kakhulu njengezixhobo zokulungisa kunye neziguquli ezisebenzayo kwimveliso yepolymer ukulawula indlela yokunyibilika, ukuphucula iipropati zomphezulu, kunye nokuphucula uzinzo lokulungisa phantsi kweemeko zemveliso ezisebenza kakhulu.
Kwiindawo zokucubungula i-thermoplastic ezifana nokukhupha, ukubumba i-injection, ukuvuthela ifilimu, kunye nokudibanisa, ii-polymers zihlala ziphantsi koxinzelelo oluphezulu lokucheba kunye nobushushu obuphezulu. Ezi meko zinokukhokelela kwimingeni eqhelekileyo yokucubungula, kubandakanya ukuhamba kokunyibilika okungazinziyo, iziphene zomphezulu (ezifana nokuqhekeka kokunyibilika kunye ne-sharkskin), ukwakheka kokufa, kunye nomgangatho wemveliso ongaguqukiyo.
Izongezo ze-silicone zenzelwe ukujongana nale mida ye-interfacial kunye ne-rheological ngokunciphisa ukungqubana kwe-polymer-metal, ukuphucula ukuthambisa kwindawo yokunyibilika, kunye nokuzinzisa indlela yokuhamba kwamanzi ngexesha lokucubungula. Ngenxa yoko, zinegalelo kwimisebenzi yemveliso esebenzayo ngakumbi kunye nokusebenza okuzinzileyo kwemveliso yokugqibela.
Zisetyenziswa kakhulu kwiinkqubo ezinkulu zepolymer, kuquka iipolyolefins (PE, PP, LLDPE, HDPE, EVA), iikhompawundi zePVC, ii-thermoplastic elastomers (TPE, TPU, TPO, TPV), kunye neeplastiki zobunjineli (ABS, PC, PA/Nylon, PBT, PET, PPS, POM, kunye nePMMA).
Ngokwembono yokucubungula, izongezo ze-silicone zisetyenziswa kwiinkqubo zokukhupha, ukubumba ngenaliti, ukuvuthela ifilimu, kunye nokudibanisa, apho zinceda ukuzinzisa i-melt rheology, ukunciphisa ukungqubana phakathi kobuso, kunye nokunciphisa iziphene ezinxulumene nomphezulu kunye nokufa phantsi kweemeko zokusebenza eziqhubekayo okanye ezikhawulezayo.
Izicelo zokusetyenziswa kokugqibela ziquka iinkqubo zocingo kunye neentambo, izinto zangaphakathi zeemoto, izixhobo zezihlangu, iipayipi, ukupakishwa okuguquguqukayo, izinto zokugquma, iipeyinti, iifayibha, kunye noluhlu olubanzi lweemveliso zeplastiki ezenziwe ngobunjineli nezilungisiweyo.
Njengoko kugxininiswa ngakumbi kushishino kwimveliso ephezulu, ulawulo oluqinileyo lomgangatho, amazinga aphantsi enkunkuma, kunye nozinzo oluphuculweyo lwezinto, izongezo ze-silicone azisajongwa njengezixhobo ezilula zokucubungula. Endaweni yoko, zidityaniswa ngakumbi njengezinto ezisebenzayo zokwenziwa ngaphakathi koyilo lwenkqubo ye-polymer, zinegalelo ngokuthe ngqo ekusebenzeni kakuhle kokucubungula kunye nokusebenza kwemveliso yokugqibela.
Ngenxa yoko, abavelisi bezongezo ze-silicone baye baba ngamaqabane aphambili kwezobuchwepheshe kulo lonke uthotho lwexabiso le-polymer lwehlabathi.
Eli nqaku ligxininisa abavelisi bezongezo ze-silicone abali-10 abaphambili kwihlabathi liphela, linceda abaprosesa ukuba bafumane ababoneleli abaphambili, ubuchwepheshe, kunye nezisombululo zezicelo zokucubungula i-polymer.

Zithini izongezo zeSilicone?
Izithako ze-silicone—ezikwabizwa ngokuba zizithako ezisekelwe kwi-silicone, izithako ze-siloxane, okanye izithako ze-polysiloxane—zizixhobo zokulungisa ezisebenzayo kunye nezinto eziphucula ukusebenza ezisekelwe kwi-polydimethylsiloxane (PDMS) okanye kwi-organosilicon compounds eguquliweyo.
Zifakwa kumanqanaba aphantsi (ngesiqhelo ukusuka kwi-0.1 ukuya kwi-5%) ukuphucula ukuqhubekeka kokusebenza, iimpawu zomphezulu, kunye nokuqina kwemveliso ixesha elide.
Imisebenzi ephambili yokusebenza
• Ukunciphisa ukungqubana kokunyibilika kunye nokuphucula indlela yokuhamba kwamanzi
• Ukuthintela iziphene zomphezulu ezifana nokuqhekeka kokunyibilika kunye nolusu loshaka
• Ukunciphisa ukwakheka kwe-die kunye nokunciphisa ukungcola kwezixhobo
• Ukuphucula ukuguda komphezulu kunye neempawu zokuchukumisa
• Ukuphucula uzinzo lwemveliso kunye nomphumo wayo

I-Chemistry ePhambili yeZongezo zeSilicone
Ukusebenza kwezongezo ze-silicone kuvela kumqolo wazo oguquguqukayo we-silicon-oxygen (Si-O), odla ngokusebenza namaqela asecaleni e-organic afana ne-methyl.
Olu lwakhiwo lwemolekyuli lukhethekileyo lubonelela:
• Uxinzelelo oluphantsi lomphezulu ukuze kuthanjiswe kakuhle
• Uzinzo oluphezulu lobushushu kunye ne-oxidative phantsi kweemeko zokucubungula ezifuna amandla
• Ukungathandi amanzi okunceda ukukhusela imiphezulu yepolymer kumswakama
• Ukutyibilika okugqwesileyo kunye nokuthambisa, kunciphisa uxinzelelo lokucheba ngexesha lokukhupha kunye nokubumba
• Ukungakwazi ukusebenza kweekhemikhali kunye nokuguquguquka, okuvumela ukuhambelana noluhlu olubanzi lweepolymers

Iintlobo zezongezo zeSilicone zanamhlanje
Izongezo ze-silicone zenzelwe ukuhlangabezana neemfuno ezithile zokusebenza ngokuxhomekeke kubunzima be-molecular, amaqela asebenzayo, kunye noyilo lwe-polymer. Iifom eziqhelekileyo zoshishino ziquka ulwelo lwe-silicone (ii-oyile), ii-siloxanes, ii-silicone eziguqulwe yi-polyether, ii-resins ze-silicone, ii-masterbatches ze-silicone, kunye nee-silicone powders.

1. I-Silicone Masterbatch
I-Silicone masterbatch yindlela yokwenziwa kwe-pelletized ekumgangatho ophezulu esetyenziswa kakhulu kushishino lwe-polymer. Le teknoloji iphambili ixhomekeke ekusasazeni ii-polymers ze-siloxane ze-ultra-high molecular weight (UHMW) kwiinkampani ezahlukeneyo ze-thermoplastic (kubandakanya ii-polyolefins, iiplastiki zobunjineli, kunye nee-elastomers ze-thermoplastic). Ihanjiswa kwimo ye-pellet eqhelekileyo, ivumela ukufunxwa okucocekileyo nokuchanekileyo ngqo kwi-thermoplastic matrix ngexesha lokudibanisa, ukukhupha, okanye ukubumba ngenaliti. Ngokungafaniyo nee-waxes zendabuko, ii-fatty acid amides, okanye ii-oyile ezinobunzima obuphantsi beemolekyuli, ii-masterbatches ze-UHMW silicone zibonelela ngokutyibilika okuphezulu komphezulu kunye nokukhululwa kwesikhunta ngelixa ziphepha ngempumelelo iziphene zokucubungula ezifana nokutyibilika kwesikrufu.

2. IiSilicone Fluids (PDMS)
IiSilicone Fluids (PDMS) ziisilicone eziphantsi ukuya kweziphakathi ezinobunzima bemolekyuli, ezithe nkqo, ezingashukumiyo ezibonakaliswa yi-repetitive silicon-oxygen (-Si-O-) backbone enamaqela asecaleni e-methyl. Kwi-polymer processing, zisebenza kakhulu njengezixhobo zokulungisa umzimba zesikhashana kunye nee-lubricants zangaphandle. Ngenxa yokuhamba kwazo okuphezulu kweemolekyuli kunye nokungabikho kwe-chemical bonding kunye ne-host polymer matrix, zinciphisa i-melt viscosity kunye ne-torque kodwa zinobunzima bokufuduka, okukhokelela ekukhutshweni komphezulu, ukutyibilika kwezikrufu, kunye nokungaphumeleli kokunamathela kwepeyinti okanye kokuprinta okulandelayo.

3. Izongezo ze-Organosilicone ezisebenzayo
Izithako ze-Organosilicone ezisebenzayo zii-copolymers ze-silicone eziguqulwe ngokweekhemikhali, okanye i-organo-modified silicone eziquka amaqela asebenzayo asebenzayo okanye asebenza nge-polar (njenge-epoxy, i-amino, i-carboxy, i-vinyl, okanye i-polyether segments) kwi-siloxane backbone okanye kwi-chain ends. Ngokungafaniyo ne-PDMS eqhelekileyo, ezi zithako zenziwe ngokweemolekyuli ukuze zisebenze njenge-interfacial modifiers kunye ne-reactive compatibilizers. Zinciphisa uxinzelelo lwe-interfacial kwaye zonyusa ukunamathelana kwesigaba phakathi kwezinto ezingahambelaniyo, zizenze zibe yimfuneko ekuphuculeni iiplastiki zobunjineli, ziphucule ukusebenza kwee-recycled/PCR polymers, kwaye ziphucule ukumanzisa kunye nokusasazwa kwe-filler (umz., ii-halogen-free flame retardants, ii-glass fibers) kwiinkqubo ze-polymer ezinamacandelo amaninzi.

4. Iipowder zeSilicone
IiSilicone Powders ziiformula zesilicone ezihamba ngokukhululekileyo, eziqinileyo, nezingamaqhekeza, ezidla ngokwenziwa ziipolymers ze-siloxane ze-ultra-high molecular weight (UHMW) ezixhonywe kwi-inorganic silica core, okanye ii-silicone resins ezi-three-dimensional spherical resins (umz., i-polymethylsilsesquioxane). Zenziwe njengeziguquli zokusebenza ezisisigxina, zidityaniswa zibe yi-thermoplastics ukuze zibonelele ngokuphuculwa komphezulu okuhlala ixesha elide—njengokukrwela okusisigxina kunye nokumelana nokuguguleka, ukunciphisa okuzinzileyo kwiCoefficient of Friction (COF), kunye neempawu zokuchasana nokuvaleka—ngaphandle kokubeka emngciphekweni iipropati zoomatshini ze-substrate okanye ukupeyintwa emva kokucutshungulwa.