1. Yadda Ake Zaɓar Dicarboxylic Acids Don Tsarin Polyester Polyol?

Sinadaran Ƙamshi: Inganta Ƙarfin Jiki da Juriyar Zafi

Acid Isophthalic (IPA) da Acid Terephthalic (PTA)

Ana amfani da sinadaran dicarboxylic acid musamman don inganta:

Terephthalic acid (PTA)yana da tsari mai layi na yau da kullun da kuma yanayin lu'ulu'u mai ƙarfi.

Lokacin da PTA ta yi aiki da gajerun sarƙoƙi kamar ethylene glycol (EG) ko 1,4-butanediol (BDO), tsarin polyester da ya haifar zai iya nuna ƙarfin yanayin lu'ulu'u, wanda ke sa polyester polyol ya zama mai kakin zuma ko tauri a zafin ɗaki.

Wannan zai iya rage:

• ✖Sauƙin sarrafawa
• ✖Daidaiton ajiya
• ✖Sauƙin amfani

Saboda haka, ba kasafai ake amfani da polyester polyester polyols masu tsarki na PTA su kaɗai a cikin tsari mai amfani ba.

Acid na Isophthalic (IPA)yana da tsarin kwayoyin halitta mara daidaito saboda ƙungiyoyin carboxyl guda biyu suna nan a matsayin meta. Wannan yana rage yanayin lu'ulu'u kuma yana inganta kwanciyar hankali na ruwa.

Polyols na polyester na IPA gabaɗaya suna ba da:

• ✔Mafi Girma Tg
• ✔Ingantaccen gaskiya
• ✔Inganta kwararar ruwa

A cikin yawancin tsarin masana'antu, ana gabatar da IPA tare da PTA ko aliphatic acid don daidaita tauri da sassauci.

Aliphatic Acids: Ƙara Sauƙin Amfani

Adipic acid (AA)

Adipic acid yana ɗaya daga cikin aliphatic dicarboxylic acid da aka fi amfani da shi a cikin samar da polyester polyol.

Sarkar sa mai sassauƙa mai nauyin carbon shida tana samar da:

• •Sassaucin ƙarancin zafin jiki
• •Kyakkyawan sassauci
• •Rage Tg

Polyols na polyester na Adipic acid yawanci suna da ƙimar Tg a cikin kewayon kusan.-60°C zuwa -40°C, ya danganta da tsarin kwayoyin halitta.

Wannan tsari yana taimakawa wajen:

• •Babban ƙarfin juriya
• •Kyakkyawan juriya ga abrasion
• •Kyakkyawan aikin injiniya

Sinadarin Sebacik (SA)

Sebacic acid yana dauke da tsawon sarkar carbon fiye da adipic acid.

Fa'idodi:

• ✔Mafi sassauci
• ✔Ingantaccen aikin yanayin zafi mai kyau
• ✔Ingantaccen halayen hydrophobic

Duk da haka, saboda tsadarsa, ana amfani da SA galibi a aikace-aikacen polyurethane masu aiki mai kyau inda ake buƙatar ingantaccen juriya ga sanyi.

Abubuwan da ke cikin Acid Mai Aiki: Dimer Acid da Phthalic Anhydride

Dimer Acid

Dimer acid yana da halaye masu zuwa:

• •Dogayen sarƙoƙin ƙwayoyin halitta masu sassauƙa
• •Halayen Hydrophobic
• •Inganta sassauci
• •Inganta juriyar hydrolysis

Duk da haka, ƙara yawan sinadarin dimer acid na iya rage Tg da tauri. Ana ɗaukarsa a matsayin tsarin polyurethane da ke buƙatar sassauci da juriya ga danshi.

Phthalic Anhydride (PA)

Phthalic anhydride wani sinadari ne mai ƙamshi mai inganci wanda ke da inganci mai kyau wajen amsawa.

Zai iya inganta:

• ✔Tauri
• ✔Tauri
• ✔Gasar farashi

Duk da haka, saboda tasirin steric, amsawar rukuni na ƙarshe ya yi ƙasa idan aka kwatanta da IPA.

Tsarin Tsarin Acid na Yau da Kullum

Tsarin hada polyester polyol da aka saba amfani da shi shine:

• •Acid mai ƙamshi: yana ba da ƙarfi da tauri
• •Aliphatic acid: yana samar da sassauci da tauri

Ya kamata a daidaita ainihin rabon gwargwadon aikace-aikacen da aka yi niyya.

2. Yadda Ake Zaɓar Diols Don Zane-zanen Polyester Polyol?

Ethylene Glycol (EG)

Ethylene glycol shine mafi sauƙin diol da ake amfani da shi a cikin sinadaran polyester.

Saboda ɗan gajeren tsarin kwayoyin halitta, EG yana samar da:

• •Babban tsari na sarkar
• •Ƙarfin yanayin crystalliation mai ƙarfi

Idan aka haɗa shi da PTA, EG na iya samar da tsarin lu'ulu'u irin na PET, wanda zai iya sa polyester polyols su yi ƙarfi a zafin ɗaki. Saboda haka, polyols masu tsarki na polyester da aka yi da EG ba kasafai ake samun su ba.

A cikin dabarun aiki, EG galibi ana haɗa shi da:

don daidaita lu'ulu'u da aikin sarrafawa.

Wani muhimmin fa'ida na EG shine:

• ✔Maras tsada
• ✔Samuwa mai faɗi

Don samar da polyester polyol bisa ga kayan PET da aka sake yin amfani da su, EG ya kasance muhimmin kayan albarkatun ƙasa.

Diethylene Glycol (DEG)

DEG yana shigar da haɗin ether cikin sarkar polyester.

Haɗin ether mai sassauƙa yana ba da:

• •Ƙananan Tg
• •Rage danko
• •Ingantaccen aikin kwarara

Ana amfani da polyols na polyester da aka gina a DEG sosai lokacin da sassaucin sarrafawa yake da mahimmanci.

Duk da haka, haɗin ether na iya samun ƙarancin juriya ga iskar shaka ta thermal na dogon lokaci. Saboda haka, tsarin DEG galibi ana haɗa shi da diols masu ƙarfi kamar NPG.

Neopentyl Glycol (NPG)

NPG ya ƙunshi tsarin carbon na quaternary tare da ƙungiyoyin methyl guda biyu.

Wannan tsari na musamman yana takaita motsi na kwayoyin halitta kuma yana samar da:

• •Mafi Girma Tg
• •Kyakkyawan kwanciyar hankali na thermal
• •Mafi kyawun juriya ga yanayi
• •Inganta juriya ga hydrolysis

Saboda ƙarfinsa mai kyau, ana amfani da NPG sosai a cikin:

• •Rufin PU
• •Aikace-aikacen waje
• •Tsarin polyurethane masu jure yanayi

1,4-Butanediol (BDO)

1,4-Butanediol yana ɗaya daga cikin mahimman diols da ake amfani da su a aikace-aikacen polyurethane elastomer da TPU.

Tsarin layinsa mai carbon huɗu yana samar da:

• •Tsarin tsari mai kyau
• •Ƙarfin hulɗar intermolecular
• •Kyakkyawan halayen injiniya

Idan aka haɗa shi da sinadaran aromatic kamar PTA, BDO na iya samar da sassan kristal masu tsari iri ɗaya da tsarin PBT.

Wannan yana taimakawa ga:

• ✔Ƙarfin juriya mafi girma
• ✔Inganta juriyar abrasion
• ✔Inganta haɗin gwiwa na zahiri

Duk da haka, yawan sinadarin BDO na iya ƙara yawan sinadarin crystallization, wanda ke sa polyester polyols ya zama mai kakin zuma ko kuma mai ƙarfi a zafin ɗaki.

Don inganta aikin sarrafawa, ana haɗa BDO tare da:

don rage yawan lu'ulu'u yayin da ake kiyaye ƙarfin injina.

Trimethylolpropane (TMP): Gabatar da Rassa Mai Sarrafawa

Trimethylolpropane (TMP) barasa ce mai aiki da yawa wacce ke ɗauke da ƙungiyoyi uku na hydroxyl. Ba kamar diols na gargajiya ba, TMP yana gabatar da tsarin rassan zuwa polyester polyols.

Ƙaramin adadin TMP zai iya ƙaruwa:

• •Rarraba ƙwayoyin halitta
• •Yawan haɗin giciye
• •Taurin polyurethane na ƙarshe

Ana amfani da TMP sosai lokacin ƙirƙirar:

• •Gilashin polyurethane masu inganci
• •Tsarin PU mai ƙarfi
• •Masu haɓaka polyurethane masu rassa

A yawancin tsare-tsare, ana kula da abubuwan da ke cikin TMP a hankali saboda yawan rassan na iya ƙara danko sosai da kuma rage yawan sarrafawa.

3. Yadda Ake Daidaita Rabon Barasa da Acid a Tsarin Polyester Polyol?

Rabon Yawan Barasa

A cikin hada sinadarin polyester polyol, galibi ana amfani da sinadaran barasa fiye da kima don cimma tsarin da aka dakatar da hydroxyl.

Ga ƙananan polyester polyols masu nauyin kwayoyin halitta, ana iya ƙara yawan barasa zuwa:1.8–2.0: 1

Ƙimar hydroxyl mafi girma tana samar da ƙarin ƙungiyoyin hydroxyl masu amsawa don ƙirƙirar polyurethane.

Duk da haka, yawan shan barasa na iya rage nauyin kwayoyin halitta kuma yana iya yin mummunan tasiri ga:

Saboda haka, dole ne a inganta rabon barasa-da-acid bisa ga aikace-aikacen polyurethane na ƙarshe.

Alaƙa Tsakanin Rabon Barasa da Darajar Acid

A lokacin hada polyol na polyester, ana ci gaba da cire ruwan da ake samarwa don haifar da esterification da condensation a gaba.

Idan yawan barasa bai isa ba:

• •Yawan sinadarin acid ya kasance mai yawa
• •Amsawa yana raguwa
• •Ƙimar acid ta ƙarshe ta zama da wahala a rage ta

Ƙarancin darajar acid yana da mahimmanci domin ragowar acid na iya shafar halayen polyurethane. Lokacin da polyester polyol ya yi hulɗa da isocyanates, ragowar danshi da abubuwan acid na iya taimakawa wajen:

Don amfani da polyurethane da yawa, ana buƙatar rage ƙimar acid a ƙasa:1 mg KOH/gwani muhimmin abu ne na inganci.

4. Yadda Ake ZaɓaMasu ƙarfafa gwiwadon Samar da Polyol na Polyester?

Zaɓin tsakanin TBT da BTO ya dogara da:

5. Sarrafa Tsarin Masana'antar Polyol na Polyester

Manyan matakai sun haɗa da:

1. Esterification
2. Ruwan da ke kewaye da iska
3. Daidaita darajar hydroxyl da ƙimar acid

Mataki na 1: Matakin Esterification

A lokacin matakin esterification, ana shigar da waɗannan kayan cikin reactor:

Amsar yawanci tana farawa ne da kimanin:180°C

Ana cire ruwan da ake samu daga esterification ta hanyar:

• •Rage sinadarin Nitrogen
• •Tsarin matsewa

Ana iya sa ido kan ci gaban martani ta hanyar:

• •Adadin tattara ruwa
• •Gwajin ƙimar acid

Mataki na 2: Matakan Juyawa Juyawa

Bayan esterification, tsarin ya shiga matakin polycondensation.

Yanayin da aka saba:

• •Zafin jiki:200–220°C
• •Rage matsin lamba: aikin injin

Injin tsotsa yana taimakawa wajen cire sauran ruwan da ya rage da kuma yawan barasa, wanda ke haifar da haɓakar ƙwayoyin halitta.

Duk da haka, yawan zafin jiki ko tsawon lokacin amsawa na iya haifar da halayen gefe, ƙaruwar launi, da kuma lalacewar polymer. Saboda haka, dole ne a kula da yanayin aiki a hankali.

Mataki na 3: Sarrafa Maɓallin Ƙarshe

Ba kamar yadda aka yi wa PET polymerization ba, samar da polyester polyol ba ya buƙatar haɓaka nauyin ƙwayoyin halitta mai yawa. Manyan alamun inganci sune:

Manufar masana'antu gama gari:Ƙimar acid <1 mg KOH/gkafin a sallame shi.

Rashin isasshen injin tsabtace iska yana ɗaya daga cikin manyan dalilan da ke haifar da:

• ✖Babban danshi da ya rage
• ✖Babban darajar acid
• ✖Rashin aikin polyurethane

6. Takaitaccen Bayani game da Tsarin Polyester Polyol

Tsarin Zane	Maɓallan Maɓalli	Ka'idar Zaɓe	Matsakaicin Nisa
Taurin ƙashi	IPA, PTA, AA, SA	Sinadaran ƙamshi suna inganta tauri; sinadarin aliphatic suna inganta sassauci	IPA/AA ≈ 7:3
Daidaita Tg	EG, DEG, NPG, BDO	EG yana ƙara yawan lu'ulu'u; DEG yana rage danko; NPG yana inganta juriya; BDO ​​yana inganta ƙarfi	Dangane da aikace-aikacen
Kula da nauyin kwayoyin halitta	Rabon barasa da acid	Yawan barasa yana haifar da tsarin da aka dakatar da hydroxyl	Barasa/Acid = 1.3
Zaɓin Mai Haɓaka	TBT vs BTO	TBT don amsawa cikin sauri; BTO don ingantaccen kwanciyar hankali na hydrolysis	BTO 0.2–0.5‰
Kula da rassan	TMP/Glycerol	Ƙaramin ƙari yana inganta yawan haɗin gwiwa	TMP ≤3 mol%

7. Ta Yaya Tsarin Polyester Polyol Ke Shafar Aikin Polyurethane?

Aikace-aikace	Zane-zanen Polyester Polyol da aka ba da shawarar
Manne na PU	Polyols ɗin polyester mai sassauƙa na AA don mannewa mai ƙarfi da tauri
Rufin PU	Tsarin IPA/NPG don tauri da juriya ga yanayi
Elastomers na TPU	Tsarin AA + BDO don ƙarfin injiniya da juriya ga abrasion
PU mai kula da ruwa	Polyols na polyester masu jure wa hydrolysis tare da ingantaccen tsarin mai kara kuzari
Fata Mai Zane	Polyols masu sassaucin ra'ayi tare da laushi mai sarrafawa

Bukatun aikace-aikace → Manufofin Aiki → Zaɓin Monomer → Tsarin tsarin ƙwayoyin halitta → Zaɓin Mai Haɓaka → Inganta tsari