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Menene polyolefins?

Polyolefins iyali ne na polyethylene da polypropylene thermoplastics.Ana samar da su galibi daga mai da iskar gas ta hanyar yin polymerisation na ethylene da propylene bi da bi.Ƙwararrensu ya sanya su zama ɗaya daga cikin fitattun robobi da ake amfani da su a yau.

Abubuwan polyolefins

Akwai nau'ikan polyolefins guda huɗu:

• LDPE (ƙananan polyethylene): LDPE an bayyana shi da kewayon yawa na 0.910-0.940 g/cm3.Yana iya jure yanayin zafi na 80 ° C ci gaba da 95 ° C na ɗan gajeren lokaci.An yi shi a cikin bambance-bambancen da ba a iya gani ba ko mara kyau, yana da sauƙin sassauƙa da tauri.
• LLDPE (Polyethylene low-density low-density): polyethylene ne mai madaidaici, mai adadi mai yawa na gajerun rassa, wanda aka saba yin shi ta hanyar copolymerization na ethylene tare da olefins mai tsayi mai tsayi.LLDPE yana da ƙarfin juriya mafi girma da tasiri mafi girma da juriyar huda fiye da LDPE.Yana da matukar sassauci kuma yana elongates a ƙarƙashin damuwa.Ana iya amfani da shi don yin fina-finai na bakin ciki kuma yana da kyau juriya ga sunadarai.Yana da kyawawan kaddarorin lantarki.Koyaya, ba shi da sauƙin aiwatarwa kamar LDPE.
• HDPE (polyethylene mai girma): HDPE sananne ne don girman girman ƙarfin-zuwa-yawa.Girman HDPE na iya zuwa daga 0.93 zuwa 0.97 g/cm3 ko 970 kg/m3.Ko da yake yawan HDPE yana da ɗan kadan sama da na ƙananan ƙarancin polyethylene, HDPE yana da ƙananan reshe, yana ba shi ƙarfin intermolecular da ƙarfi fiye da LDPE.Har ila yau yana da wuya kuma ya fi dacewa kuma yana iya jure yanayin zafi kadan (120 ° C na gajeren lokaci).
• PP (polypropylene): Yawan PP yana tsakanin 0.895 da 0.92 g/cm³.Saboda haka, PP shine filastik kayayyaki tare da mafi ƙarancin yawa.Idan aka kwatanta da polyethylene (PE) yana da ingantaccen kaddarorin inji da juriya na thermal, amma ƙarancin juriya na sinadarai.PP yawanci tauri ne kuma mai sassauƙa, musamman idan an haɗa shi da ethylene.

Aikace-aikace na polyolefins

Halaye na musamman na nau'ikan polyolefins daban-daban suna ba da kansu ga aikace-aikace daban-daban, kamar:

• LDPE: fim ɗin cin abinci, jakunkuna masu ɗaukar kaya, fim ɗin noma, murfin kwali na madara, murfin kebul na lantarki, jakunkuna masu nauyi masu nauyi.
• LLDPE: fim mai shimfiɗa, fim ɗin marufi na masana'antu, kwantena masu bangon bakin ciki, da nauyi, matsakaici da ƙananan jaka.
• HDPE: akwatuna da kwalaye, kwalabe (na kayan abinci, kayan wanka, kayan kwalliya), kwantena abinci, kayan wasan yara, tankunan mai, kayan masana'antu da fim, bututu da kayan gida.
• PP: marufi na abinci, gami da yoghurt, tukwanen margarine, kayan ciye-ciye masu daɗi da ciye-ciye, kwantena masu hana microwave, filayen kafet, kayan lambu, marufi da kayan aikin likita, kaya, kayan dafa abinci, da bututu.