Structure Modifaction Of Vermiculite And The Preparation Of Rubber / Vermiculite Nanocomposites

Vermiculite has a good cation exchange capacity,expandability,and absorption capacity because of its unique layer structure It was widely used in agriculture,industry,animal husbandry,environment protection,building materials.In recent years,many scholars dedicated to the study of vermiculite.However,preparation of structure modified vermiculite/ styrene-butadiene rubber composite is not found in literatures.In this paper,structure modificationand organic intercalation of vermiculite and preparation of structure modified vermiculite/rubber nanocomposites were carried out.The results are as follows:1.The vermiculite from Hebei mainly includes vermiculite and vermiculite-mica mixed layer mineral,and a small amounts of micaand hornblende.The cation exchange capacity(CEC)of vermiculite in the process of acid leaching,i.e.structure modification,increased firstly and then decreased with increasing the concentration of hydrochloric acid.The CEC of raw vermiculitewas 40.8 mmol/100 g.When the concentration of hydrochloric acid was 0.003 mol/L,the CEC of the structure modified vermiculite increased to 50.8 mmol/100 g.Further increased the hydrochloric acid concentration to 0.1 mol/L,the CEC of structure modified vermiculite reduced to 10.2 mmol/100 g.2.DTAB,TTAB and CTAB were all effectively intercalated into raw vermiculite and structure modified vermiculite.The layer spacing of intercalated vermiculite increased with increasing the chain length and dosage of intercalating agent.When the dosage of CTAB is over 4 times CEC of vermiculite,the increase of the layer spacing of intercalated vermiculite was not obvious.Vermiculite modified with 0.003 mol/L hydrochloric acid was intercalated most effectively and the one modified with 0.1 mol/L HCl was the worst.It shows that the higher the cation exchange capacity of structure modified vermiculite,the larger its layer spacing.3.Structure modified styrene butadiene rubber/vermiculite nanocomposite with good tensile strength and tearing elongation property was prepared.When the concentration of hydrochloric acid was 0.003 mol/L,the mechanical properties of nanocomposite is the best.Larger layer spacing was in favour of intercalation of polymers into the interlayer and exfoliation of vermiculite.At the same time,the mechanical properties of composite materials was improved.Proper acid treatment and organic intercalation modification of vermiculite,helps the rubber molecules into the interlayer,which was combined with the help of vermiculite and rubber matrix,improved the mechanical properties of composite materials.