Cov txheej txheem:

Koj npaj PVA li cas?
Koj npaj PVA li cas?

Video: Koj npaj PVA li cas?

Video: Koj npaj PVA li cas?
Video: kuv paub koj xav li cas ( KAB LIA LAUJ ) 2021 2024, Kaum ib hlis
Anonim

Nyhav 40 grams polyvinyl cawv rau hauv 1-Lborosilicate iav beaker. Sau lub beaker rau 1-L cim nrog dej kub; do. Npog nrog microwaveable yas qhwv. Microwaveon siab li 3 feeb; do thiab kub rau ib qho ntxiv 3 feeb.

Ib yam li ntawd, tej zaum koj yuav nug, koj yuav ua li cas yaj PVA?

Yuav ua li cas yaj PVA

  1. Dej sov. Cov dej sov yuav txo lub sijhawm so.
  2. Sib tov. Siv nplawm/khiav dej kom txo tau lub sij hawm dissolving.
  3. Pliers. Koj tuaj yeem ua kom ceev PVA tawg los ntawm kev tso cov ntawv luam tawm hauv dej li ntawm 10 feeb, tom qab ntawd tshem tawm feem ntau ntawm kev txhawb nqa nrog cov pliers.

Ib yam li ntawd, PVA hmoov siv rau dab tsi? Polyvinyl cawv ( PVA , qee zaum hu ua PVOH) yog dej-soluble polymer siv dav inadhesives, xim, sealants, coatings, textiles, plastics, thiab lwm yam. Thepolymer yog ib txwm nkag rau hauv hmoov daim ntawv thiab ntau qib muaj nyob nrog sib txawv viscosity thiab solubility yam ntxwv.

Ua li no, PVA ua li cas?

Hloov chaw, PVA yog ua los ntawm dissolving lwmpolymer, polyvinyl acetate (PVAc), nyob rau hauv ib tug cawv xws li methanoland kho nws nrog ib tug alkaline catalyst xws li sodium hydroxide. Cov tshuaj qauv ntawm lub resulting vinyl cawv repeatingunits yog:.

PVA txheej yog dab tsi?

PVA yog ib qho hluavtaws, tsis muaj ntxhiab thiab tsis muaj xim polymer uas nyiam rau txheej daim ntawv thov. Nws tuaj yeem yaj hauv dej ntawm 80-90 ° C. Yog koj xav tau lub tsho tiv no hydrophilic los yog dej soluble nto, koj siv lub PVA daws ncaj qha.

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