Rosin guduro
Har ila yau, yana da halayen carboxyl kamar esterification, barasa, samuwar gishiri, decarboxylation, da aminolysis.
Sake sarrafawa na biyu na rosin yana dogara ne akan halayen rosin tare da ƙungiyoyi biyu da ƙungiyoyin carboxyl, kuma rosin an canza shi don samar da jerin rosin da aka gyara, wanda ke inganta ƙimar amfani da rosin.
Ana amfani da resin rosin a cikin masana'antar manne don ƙara danko, canza mannewa, kaddarorin haɗin kai, da sauransu.
Rosin resin wani fili ne na tricyclic diterpenoid, wanda aka samu a cikin lu'ulu'u masu walƙiya monoclinic a cikin ethanol mai ruwa. Matsayin narkewa shine 172 ~ 175 ° C, kuma jujjuyawar gani shine 102 ° (ethanol anhydrous). Mai narkewa a cikin ruwa, mai narkewa a cikin ethanol, benzene, chloroform, ether, acetone, carbon disulfide da dilute mai ruwa sodium hydroxide bayani.
Shi ne babban bangaren na halitta rosin guduro. Esters na rosin acid (irin su methyl esters, vinyl alcohol esters, da glycerides) ana amfani da su a cikin fenti da varnishes, amma kuma a cikin sabulu, robobi, da resins.
Yana da polyol ester na rosin acid. Abubuwan da aka fi amfani da su sune glycerol da pentaerythritol. Polyol
Ma'anar laushi na pentaerythritol rosin ester ya fi na glycerol rosin ester, kuma aikin bushewa, taurin, juriya na ruwa da sauran kaddarorin varnish sun fi na varnish da aka yi da glycerol rosin ester.
Idan an yi amfani da ester mai dacewa da aka yi daga rosin polymerized ko rosin hydrogenated azaman kayan albarkatun kasa, yanayin canza launin yana raguwa, kuma ana inganta wasu kaddarorin zuwa wani ɗan lokaci. Wurin laushi na rosin ester polymerized ya fi na rosin ester, yayin da madaidaicin tausasawa na rosin ester ya yi ƙasa.
Rosin esters ana tace su daga rosin resins. Rosin resin ana yin shi ta hanyar esterification na rosin. Misali, rosin glyceride an yi shi da rosin ta hanyar esterification na glycerol.
Babban ɓangaren resin rosin shine resin acid, wanda shine cakuda isomers tare da tsarin kwayoyin C19H29 COOH; rosin ester yana nufin samfurin da aka samu bayan esterification na rosin resin, saboda wani abu ne na daban, don haka ba zai yiwu a ce iyakar wane ne ba. babba.
Rosin-gyara phenolic guduro har yanzu yafi halin da tsarin kira na gargajiya. Mataki na daya shine a haxa phenol, aldehyde da sauran albarkatun ƙasa da rosin sannan a mayar da martani kai tsaye.
Tsarin tsari yana da sauƙi, amma buƙatun sarrafawa kamar dumama na gaba suna da girma; Mataki na biyu shine don haɗa tsaka-tsakin phenolic condensate a gaba, sa'an nan kuma amsa tare da tsarin rosin.
Kowane mataki na musamman na ƙarshe yana samar da guduro tare da ƙarancin ƙimar acid, babban wurin laushi, da nau'in kwatankwacin kwayoyin halitta da wani ƙayyadaddun solubility a cikin ma'adanai mai kaushi.
1. Tsari ɗaya-ɗaya Ƙa'idar amsawa:
â Haɗin resole phenolic resin: Alkylphenol yana ƙara zuwa rosin narkakkar, kuma paraformaldehyde yana wanzuwa a cikin tsarin a cikin nau'in granular, sa'an nan kuma ya bazu zuwa monomer formaldehyde, wanda ke samun amsawar polycondensation tare da alkylphenol.
Samuwar methine quinone: rashin ruwa a cikin zafin jiki mai girma, yayin da ake yin dumama, ayyukan methylol a cikin tsarin yana ƙaruwa da sauri, rashin ruwa a cikin kwayoyin methylol yana faruwa, kuma yanayin daɗaɗɗen etherification tsakanin kwayoyin methylol yana faruwa, yana tasowa, yana tasowa. Daban-daban na phenolic condensates tare da digiri daban-daban na polymerization suna samuwa.
â ¢ Ƙara rosin zuwa methine quinone da anhydride maleic: Ƙara maleic anhydride a 180 °C, yi amfani da haɗin haɗin maleic anhydride mara kyau da haɗin haɗin biyu a cikin rosin acid don ƙarawa, kuma a lokaci guda ƙara methine quinone zuwa rosin. Har ila yau, acid ɗin yana jujjuya haɓakar ƙari na Diels-Alder don samar da mahadi na chromofuran na maleic anhydride.
⣠Esterification na polyol: Kasancewar yawancin ƙungiyoyin carboxyl a cikin tsarin zai lalata ma'auni na tsarin kuma ya haifar da rashin kwanciyar hankali na guduro.
Sabili da haka, muna ƙara polyols kuma muna amfani da amsawar esterification tsakanin ƙungiyoyin hydroxyl na polyols da ƙungiyoyin carboxyl a cikin tsarin don rage ƙimar acid ɗin tsarin. A lokaci guda, ta hanyar esterification na polyols, an kafa manyan polymers masu dacewa da tawada na bugu.
2. Ƙa'idar amsawa ta matakai biyu:
â Karkashin aikin mai kara kuzari na musamman, formaldehyde yana samar da nau'ikan resole phenolic oligomers mai dauke da adadi mai yawa na methylol mai aiki a cikin maganin alkylphenol. Tun da tsarin ba shi da tasirin hanawa na rosin acid, ana iya haɗa condensates tare da raka'a sama da 5 na phenolic.
â¡ Polyol da rosin suna esterified a babban zafin jiki, kuma a karkashin aiki na asali mai kara kuzari, da ake bukata darajar acid za a iya isa da sauri.
â ¢ A cikin rosin polyol ester da aka mayar da martani, a hankali ƙara haɗakar resole phenolic resin dropwise, sarrafa ƙimar juzu'i da zafin jiki, sa'annan a kammala ƙarar juzu'i. Rashin ruwa a yanayin zafi mai tsayi, kuma a ƙarshe an kafa resin da ake so.
Amfanin tsarin mataki daya shine cewa an cire sharar a cikin nau'i na tururi, wanda ke da sauƙin magancewa a cikin kare muhalli. Duk da haka, phenolic condensation halayen da ke faruwa a cikin rosin narkakkar yana da wuyar samun halayen gefe da yawa saboda yawan zafin jiki da rashin daidaituwa.
Daidaitawar yana da wahalar sarrafawa, kuma ba shi da sauƙi a sami samfuran resin barga. Amfanin hanyar mataki biyu shine cewa za'a iya samun oligomer na phenolic condensation tare da ingantaccen tsari da abun da ke ciki, kowane matakin amsa ya fi sauƙi don saka idanu, kuma ingancin samfurin yana da inganci.
Abin da ke da lahani shi ne, dole ne a kawar da condensate na al'ada na al'ada na al'ada ta acid kuma a wanke shi da ruwa mai yawa don cire gishiri kafin ya iya amsawa da rosin, wanda ya haifar da ruwa mai yawa mai dauke da phenol, wanda ke haifar da mummunar lalacewa. yanayi kuma yana cinye lokaci mai yawa.
Tambayar daidai da kuskure na matakai guda ɗaya da matakai biyu sun daɗe suna mayar da hankali ga masana'antun tawada. Amma kwanan nan, tare da nasarar ci gaban hanyar da ba a wanke ba don haɗawa da condensate phenolic, an inganta fahimtar hanyar haɗin matakai biyu.
