Makhalidwe oyatsa a PVC ndi ovuta kuyaka, amazimitsa mwamsanga atangochoka pamoto, lawi ndi utsi wachikasu ndi woyera, ndipo pulasitiki imafewetsa ikayaka, imatulutsa fungo lopweteka la chlorine.
Polyvinyl chloride resin ndi pulasitiki wamitundu yambiri.Zowonjezera zosiyanasiyana zitha kuwonjezeredwa malinga ndi ntchito zosiyanasiyana.Chifukwa chake, ndi nyimbo zosiyanasiyana, zopangidwa zake zimatha kuwonetsa zinthu zosiyanasiyana zakuthupi komanso zamakina.Mwachitsanzo, imatha kugawidwa kukhala zinthu zofewa komanso zolimba kapena popanda plasticizer.Nthawi zambiri, zinthu za PVC zili ndi ubwino wa kukhazikika kwa mankhwala, kukana kwamoto ndi kuzimitsa, kukana kuvala, phokoso ndi kugwedezeka, mphamvu zambiri, kutsekemera kwa magetsi, mtengo wotsika, magwero azinthu zambiri, kutsekeka kwa mpweya wabwino, etc. kukhazikika kwamafuta ndi kukalamba kosavuta pansi pakuchita kwa kuwala, kutentha ndi mpweya.PVC utomoni wokha si poizoni.Ngati zinthu zopangidwa ndi pulasitiki zopanda poizoni, zolimbitsa thupi ndi zinthu zina zothandizira zimagwiritsidwa ntchito, zimakhala zopanda vuto kwa anthu ndi nyama.Komabe, mapulasitiki ambiri ndi zokhazikika zomwe zimagwiritsidwa ntchito muzinthu za PVC zomwe zimawonedwa pamsika ndizowopsa.Chifukwa chake, kupatula zinthu zopanda poizoni, sizingagwiritsidwe ntchito kukhala ndi chakudya.
1. Kuchita kwathupi
PVC resin ndi thermoplastic yokhala ndi mawonekedwe amorphous.Pansi pa kuwala kwa ultraviolet, PVC yolimba imapanga fluorescence yoyera ya buluu kapena yofiirira, pamene PVC yofewa imatulutsa fulorosisi yoyera ya buluu kapena yabuluu.Kutentha kukakhala 20 ℃, refractive index ndi 1.544 ndipo mphamvu yokoka ndi 1.40.Kuchulukana kwazinthu zokhala ndi plasticizer ndi filler nthawi zambiri kumakhala pakati pa 1.15 ~ 2.00, kachulukidwe ka thovu lofewa la PVC ndi 0.08 ~ 0.48, ndipo kachulukidwe ka thovu lolimba ndi 0.03 ~ 0.08.Mayamwidwe amadzi a PVC sikuyenera kupitirira 0.5%.
Zomwe zimapangidwira komanso zamakina a PVC zimadalira kulemera kwa maselo a utomoni, zomwe zili mu plasticizer ndi filler.Kulemera kwa maselo a utomoni, kumapangitsa kuti makinawo aziwoneka bwino, kukana kuzizira komanso kukhazikika kwa kutentha, koma kutentha kwa kutentha kumafunikanso kukhala apamwamba, choncho n'zovuta kupanga;Kulemera kwa maselo otsika ndikosiyana ndi zomwe zili pamwambazi.Ndi kuchuluka kwa zodzaza zodzaza, mphamvu yamanjenje imachepa.
2. Kuchita kwa kutentha
Malo ochepetsera a PVC resin ali pafupi ndi kutentha kwa kutentha.Yayamba kuwola pa 140 ℃, ndipo imawola mwachangu pa 170 ℃.Pofuna kuonetsetsa ndondomeko yachibadwa ya kuumba, zizindikiro ziwiri zofunika kwambiri za PVC resin zimatchulidwa, zomwe ndi kutentha kwa kuwonongeka ndi kukhazikika kwa kutentha.Zomwe zimatchedwa kutentha kwa kutentha ndi kutentha pamene kuchuluka kwa hydrogen chloride kumatulutsidwa, ndipo zomwe zimatchedwa kukhazikika kwa kutentha ndi nthawi yomwe hydrogen chloride imatulutsidwa nthawi zambiri kutentha (nthawi zambiri 190 ℃).Pulasitiki ya PVC imawola ngati iwonetsedwa kwa 100 ℃ kwa nthawi yayitali, pokhapokha ngati pali zowonjezera zamchere.Ngati ipitilira 180 ℃, imawola mwachangu.
Kutentha kwa nthawi yayitali kwa zinthu zambiri zapulasitiki za PVC sayenera kupitirira 55 ℃, koma kutentha kwa nthawi yayitali kwa PVC pulasitiki ndi chilinganizo chapadera kumatha kufika 90 ℃.Zofewa za PVC zimawumitsa kutentha pang'ono.Mamolekyu a PVC ali ndi maatomu a klorini, kotero iwo ndi ma copolymers ake nthawi zambiri samva malawi, amadzizimitsa okha komanso opanda kudontha.
3. Kukhazikika
Utomoni wa polyvinyl chloride ndi polima wosakhazikika, womwe umasokonezanso chifukwa cha kuwala ndi kutentha.Njira yake ndikutulutsa hydrogen chloride ndikusintha mawonekedwe ake, koma pang'ono.Panthawi imodzimodziyo, kuwonongeka kudzapititsidwa patsogolo pamaso pa mphamvu yamakina, mpweya, fungo, HCl ndi ayoni ena achitsulo.
Pambuyo pochotsa HCl ku PVC resin, maunyolo osakanikirana amapangidwa pa unyolo waukulu, ndipo mtunduwo udzasintha.Kuchuluka kwa kuwonongeka kwa hydrogen chloride kumawonjezeka, utomoni wa PVC umasintha kuchokera ku zoyera mpaka zachikasu, zowuka, zofiira, zofiirira komanso zakuda.
4. Kuchita kwamagetsi
Mphamvu zamagetsi za PVC zimadalira kuchuluka kwa zotsalira mu polima ndi mtundu ndi kuchuluka kwa zowonjezera zosiyanasiyana mu formula.Mphamvu zamagetsi za PVC zimagwirizananso ndi kutentha: pamene kutentha kumapangitsa kuti PVC iwonongeke, kutsekemera kwake kwa magetsi kudzachepetsedwa chifukwa cha kukhalapo kwa ayoni a kloridi.Ngati ayoni ambiri a kloridi sangathe kuchepetsedwa ndi zoletsa zamchere (monga mchere wamchere), kutchinjiriza kwawo kwamagetsi kudzachepetsedwa kwambiri.Mosiyana ndi ma polima osakhala a polar monga polyethylene ndi polypropylene, magetsi a PVC amasintha ndi mafupipafupi ndi kutentha, mwachitsanzo, dielectric yake nthawi zonse imachepa ndi kuwonjezeka kwafupipafupi.
5. Mankhwala katundu
PVC ili ndi kukhazikika kwamphamvu kwamankhwala ndipo ndi yamtengo wapatali ngati anticorrosive material.
PVC ndi yokhazikika ku ma inorganic acid ndi maziko ambiri.Sidzasungunuka ikatenthedwa ndipo idzawola kuti itulutse hydrogen chloride.Chopangidwa cha bulauni chosasungunuka chosasungunuka chinakonzedwa ndi azeotropy ndi potaziyamu hydroxide.Kusungunuka kwa PVC kumakhudzana ndi kulemera kwa maselo ndi njira ya polymerization.Nthawi zambiri, solubility amachepetsa ndi kuwonjezeka polima maselo kulemera, ndi solubility wa lotion utomoni woipa kuposa kuyimitsidwa utomoni.Ikhoza kusungunuka mu ketoni (monga cyclohexanone, cyclohexanone), zosungunulira zonunkhira (monga toluene, xylene), dimethylformyl, tetrahydrofuran.PVC utomoni pafupifupi insoluble mu plasticizers firiji, ndipo kwambiri amatupa kapena ngakhale kusungunuka pa kutentha kwambiri.
⒍ kusinthasintha
PVC ndi polima amorphous popanda malo osungunuka.Ndi pulasitiki ikatenthedwa mpaka 120 ~ 150 ℃.Chifukwa cha kusakhazikika kwake kwa kutentha, imakhala ndi HCl pang'ono pa kutentha kumeneku, zomwe zimalimbikitsa kuwonongeka kwake.Chifukwa chake, alkaline stabilizer ndi HCl ziyenera kuwonjezeredwa kuti ziletse kusweka kwake.PVC yoyera ndi chinthu cholimba, chomwe chiyenera kuwonjezeredwa ndi pulasitiki yoyenera kuti chikhale chofewa.Pazinthu zosiyanasiyana, zowonjezera monga zoyezera UV, zodzaza, zothira mafuta, ma pigment, anti mildew agents ndi zina zotero ziyenera kuwonjezeredwa kuti ziwonjezeke magwiridwe antchito a zinthu za PVC.Monga mapulasitiki ena, zinthu za utomoni zimatsimikizira momwe zinthu zilili komanso momwe zimapangidwira.Kwa PVC, katundu wa utomoni wokhudzana ndi kukonza amaphatikizapo kukula kwa tinthu, kukhazikika kwamafuta, kulemera kwa maselo, diso la nsomba, kachulukidwe kachulukidwe, chiyero, zonyansa zakunja ndi porosity.The mamasukidwe akayendedwe ndi gelatinization zimatha PVC phala, phala, etc. ayenera kutsimikiza, kuti adziwe zinthu processing ndi khalidwe mankhwala.
Nthawi yotumiza: Jul-07-2022