Musiyano wakanyanya kukosha pakati pepurasitiki nerabha ndewekuti deformation yepurasitiki ipurasitiki deformation, nepo rubha iri elastic deformation.Mune mamwe mazwi, plastiki haisi nyore kudzorera kumamiriro ayo epakutanga mushure mekugadzirisa, asi rabha iri nyore.Iyo elasticity yepurasitiki idiki kwazvo, kazhinji isingasviki 100%, nepo rubber inogona kusvika 1000% kana kupfuura.Yakawanda yekuumbwa kwepurasitiki inopedzwa uye maitiro echigadzirwa anopedzwa, nepo kuumbwa kwerabha kunoda vulcanization process.
Plastiki nerabha zvese zvinhu zvepolymer, izvo zvinonyanya kuumbwa nekabhoni neatomu rehydrogen, uye mamwe ane mashoma eokisijeni, nitrogen, chlorine, silicon, fluorine, sarufa nemamwe maatomu.Vane zvinhu zvakakosha uye kushandiswa kwakakosha.Plastics pakamuri tembiricha Yakasimba, yakaoma kwazvo, uye haigone kutambanudzwa nekuremara.Iyo rabha haina kukwirira mukuoma, elastic, uye inogona kutambanudzwa kuti ive yakareba.Inogona kudzorerwa kune chimiro chayo chepakutanga kana ichimira kutambanudza.Izvi zvinokonzerwa nemaitiro avo akasiyana-siyana.Mumwe mutsauko ndewekuti Purasitiki inogona kudzokororwa uye kushandiswazve kakawanda, nepo rabha haigone kudzokororwa zvakananga.Inogona chete kugadziriswa kuva rabha yakadzorerwa isati yashandiswa.Chimiro chepurasitiki pane anopfuura 100 madhigirii kusvika 200 madhigirii uye chimiro cherabha pa60 kusvika 100 madhigirii.Saizvozvowo, plastiki haisanganisi rubber.
Nzira yekusiyanisa sei plastiki kubva kupurasitiki?
Kubva pakubata kwekuona, rabha ine nyoro, yakasununguka uye yakapfava kubata, uye ine imwe dhigirii yekunyungudika, nepo plastiki inelastic zvachose uye ine imwe dhigirii yekuomarara nekuti yakaoma uye yakawanda brittle.
Kubva pane tensile stress-strain curve, plastiki inoratidza yakakwira Young's modulus padanho rekutanga rekunetsana.The strain curve ine kukwira kwakadzika, uyezve inobereka, kureba uye kutsemuka kunoitika;rabha kazhinji ine diki deformation nhanho.Kushushikana kuri pachena kunosimuka, uye yobva yapinda munhanho yekusimuka zvinyoro nyoro, kudzamara iyo stress-strain curve ichiratidza nzvimbo yakakwira kana yave kuda kutsemuka.
Kubva pane thermodynamic point yekuona, plastiki iri pazasi pegirazi tembiricha yechinhu chiri mukushandiswa tembiricha renji, nepo rabha inoshanda munzvimbo yakadzikama pamusoro peiyo tembiricha yegirazi.
Nguva yekutumira: Zvita-31-2021