Uthelekiso lwe-LLDPE kunye ne-LDPE.

I-polyethylene enoxinano oluphantsi olunemigca, eyahlukileyo ngokwesakhiwo kwi-polyethylene enoxinano oluphantsi olunemigca ngokubanzi, kuba akukho masebe amade eetheyini. Ulungelelwano lwe-LLDPE luxhomekeke kwiinkqubo ezahlukeneyo zemveliso kunye nokucubungula ze-LLDPE kunye ne-LDPE. I-LLDPE idla ngokwenziwa yi-copolymerization ye-ethylene kunye ne-alpha olefins ephezulu efana ne-butene, i-hexene okanye i-octene kubushushu obuphantsi kunye noxinzelelo. I-polymer ye-LLDPE eveliswa yinkqubo ye-copolymerization inomlinganiselo omncinci we-molecular distribution kune-LDPE eqhelekileyo, kwaye kwangaxeshanye inesakhiwo esilinganayo esenza ukuba ibe neempawu ezahlukeneyo ze-rheological.

iipropati zokuhamba kwamanzi anyibilikisiweyo

Iimpawu zokuhamba kwe-LLDPE ezinyibilikayo zilungelelaniswe neemfuno zenkqubo entsha, ingakumbi inkqubo yokukhupha iifilimu, enokuvelisa iimveliso ze-LLDPE ezikumgangatho ophezulu. I-LLDPE isetyenziswa kuzo zonke iimarike zemveli ze-polyethylene. Ukwandiswa kokwandiswa, ukungena, ukuchaphazeleka kunye nokumelana nokukrazula kwenza i-LLDPE ifaneleke kwiifilimu. Ukumelana kwayo okuhle kakhulu nokuqhekeka koxinzelelo lokusingqongileyo, ukumelana nempembelelo kubushushu obuphantsi kunye nokumelana nokuqhekeka kwenza i-LLDPE ibe nomtsalane kwiipayipi, ukukhutshwa kwamaphepha kunye nazo zonke izicelo zokubumba. Ukusetyenziswa kwamva nje kwe-LLDPE kunjenge-mulch kwiindawo zokulahla inkunkuma kunye nee-linings zamachibi enkunkuma.

Imveliso kunye neempawu

Imveliso ye-LLDPE iqala ngee-catalysts zesinyithi eziguqukayo, ingakumbi zohlobo lweZiegler okanye lwePhillips. Iinkqubo ezintsha ezisekelwe kwii-catalysts zesinyithi ezisuka kwi-cycloolefin ziyindlela enye yokuvelisa i-LLDPE. I-reaction yokwenyani ye-polymerization inokwenziwa kwii-reactors zesisombululo kunye ne-gas phase. Ngokwesiqhelo, i-octene i-copolymerized nge-ethylene kunye ne-butene kwi-reactor yesigaba sesisombululo. I-Hexene kunye ne-ethylene zi-polymerized kwi-reactor yesigaba segesi. I-resin ye-LLDPE eveliswa kwi-reactor yesigaba segesi ikwimo yamasuntswana kwaye inokuthengiswa njengomgubo okanye isetyenzwe ngakumbi ibe zii-pellets. Isizukulwana esitsha se-super LLDPE esekelwe kwi-hexene kunye ne-octene siphuhlisiwe yiMobile, i-Union Carbide. Iinkampani ezifana neNovacor kunye neDow Plastics ziqalisiwe. Ezi zinto zinomda omkhulu wokuqina kwaye zinamandla amatsha okusetyenziswa ngokuzenzekelayo kokususa iibhegi. I-resin ye-PE ephantsi kakhulu (uxinano olungaphantsi kwe-0.910g/cc.) nayo ivele kwiminyaka yakutshanje. I-VLDPES inokuguquguquka kunye nokuthamba okungenakuphunyezwa yi-LLDPE. Iipropati zee-resin ngokubanzi zibonakala kwi-melt index kunye noxinano. Isalathisi sokunyibilika sibonisa ubunzima obuphakathi beemolekyuli ze-resin kwaye ngokuyintloko silawulwa bubushushu bokusabela. Ubunzima obuphakathi beemolekyuli abuxhomekekanga kulwabiwo lwe-molekyuli (MWD). Ukukhethwa kweCatalyst kuchaphazela i-MWD. Ubuninzi bumiselwa kukuxinana kwe-comonomer kwi-polyethylene chain. Ukuxinana kwe-comonomer kulawula inani lamasebe amafutshane e-chain (ubude bawo buxhomekeke kuhlobo lwe-comonomer) kwaye ngaloo ndlela kulawula ukuxinana kwe-resin. Okukhona ukuxinana kwe-comonomer kuphezulu, kokukhona ukuxinana kwe-resin kuphantsi. Ngokwesakhiwo, i-LLDPE yahlukile kwi-LDPE kwinani nohlobo lwamasebe, i-LDPE enoxinzelelo oluphezulu inamasebe amade, ngelixa i-LDPE ethe ngqo inamasebe amafutshane kuphela.

ukucubungula

Zombini i-LDPE kunye ne-LLDPE zine-rheology okanye i-melt flow egqwesileyo. I-LLDPE inobuthathaka obuncinci bokucheba ngenxa yokusasazwa kwayo okuncinci kobunzima beemolekyuli kunye namasebe amafutshane eentambo. Ngexesha lokucheba (umz. ukukhupha), i-LLDPE igcina i-viscosity enkulu kwaye ke ngoko kunzima ukuyicubungula kune-LDPE ene-melt index efanayo. Kwi-extrusion, ubuthathaka obuphantsi bokucheba kwe-LLDPE buvumela ukukhululeka ngokukhawuleza koxinzelelo lwee-polymer molecular chains, kwaye ngaloo ndlela ubuthathaka obuphantsi beempawu zomzimba kutshintsho kwi-blow-up ratio. Kwi-melt extension, i-LLDPE iyahluka phantsi kweentlobo ezahlukeneyo. Ngokubanzi ine-viscosity ephantsi ngesantya. Oko kukuthi, ayizukuxinezeleka xa yoluliwe njenge-LDPE. Iyanda ngesantya sokuguqulwa kwe-polyethylene. I-LDPE ibonisa ukwanda okumangalisayo kwe-viscosity, okubangelwa kukudibana kwee-molecule chains. Le nto ayibonwa kwi-LLDPE kuba ukungabikho kwamasebe amade eentambo kwi-LLDPE kugcina i-polymer ingenangxaki. Le propati ibaluleke kakhulu kwizicelo zefilimu encinci. Kuba iifilimu ze-LLDPE zinokwenza iifilimu ezincinci ngokulula ngelixa zigcina amandla aphezulu kunye nokuqina. Iimpawu ze-rheological ze-LLDPE zingashwankathelwa ngokuthi "ziqinile xa zishearwe" kwaye "zithambile xa zinwenwa".