EFFECTS OF GRAFTED VINYL TRIETHOXY SILANE ON MOISTURE CROSSLINKED EPDM

ABSTRACT An EPDM terpolymer grafted with silane vinyl triethoxysilane (EPDM-g-VTES) was prepared by melt grafting, with dicumyl peroxide (DCP) as an initiator. Next, dibutyl tin dilaurate was added as a catalyst to promote moisture crosslinking of EPDM-g-VTES. By means of the rheological response of the rubber compound, Fourier transform infrared spectroscopy, and moving die rheometer, the VTES graft ratio and DCP partial crosslinking (pre-crosslinking) of EDPM-g-VTES were characterized to show the feasibility of moisture crosslinking. The mechanical properties of moisture crosslinked EPDM-g-VTES specimens were tested by universal material tester. The results showed that when the weight ratio of VTES to DCP was fixed at 15:1, the VTES graft ratio and DCP partial crosslinking of EDPM-g-VTES increased with the increase of VTES content. But the torque in the moisture crosslinking curve of EPDM-g-VTES increased significantly with the extension of crosslinking time, which proved that EPDM grafted with VTES was cured by moisture successfully. The tensile strength and elongation at break of EPDM-g-VTES were improved by moisture cure. Furthermore, the moisture cured specimen with 3 wt% VTES had the best mechanical performance.

Chemical Modifications of Continuous Aramid Fiber for Wood Flour/High-Density-Polyethylene Composites with Improved Interfacial Bonding

To expand the use of wood plastic composites in the structural and engineering constructions applications, continuous aramid fiber (CAF) with nondestructive modification was incorporated as reinforcement material into wood-flour and high-density-polyethylene composites (WPC) by extrusion method with a special die. CAF was treated with dopamine (DPA), vinyl triethoxysilane (VTES), and DPA/VTES, respectively. The effects of these modifications on compatibility between CAF and WPCs and the properties of the resulting composites were explored. The results showed that compared with the original CAF, the adhesion strength of DPA and VTES combined modified CAF and WPCs increased by 143%. Meanwhile, compared with pure WPCs, CAF after modification increased the tensile strength, tensile modulus, and impact strength of the resulting composites by 198, 92, and 283%, respectively.

Study on the graft modification mechanism of macroporous silica gel surface based on silane coupling agent vinyl triethoxysilane

Study on the mechanism of the alkylation reaction on the surface of porous silica gel.

Differential Selective Etching of Functional Groups Strategy for Preparation of Organic Hollow Porous Silica

In this study, different structural of organic hollow porous silica were prepared based on differential selective etching of functional groups strategy, using ammonia as catalyst, cetyltrimethylammonium bromide (CTAB) as pore-forming agent and emulsifier, cyano silica (CN-SiO2) or vinyl silica (V-SiO2) formed by hydrolysis condensation of 2-cyanoethyl triethoxysilane (CTES) or vinyl triethoxysilane (VTES) were used as cores, NH-SiO2 prepared by 3-aminopropyl triethoxysilane (APTES), SH-SiO2 prepared by mercaptopropyl trimethoxysilane (MPTMS) and UD-SiO2 prepared by urea-propyl triethoxysilane (UPTES) as shells, separately. The morphology and structure of the products were characterized by scanning electron microscopy(SEM) and transmission electron microscopy(TEM). The study results showed that CN-SiO2 as core was considered to be benefit for the preparation of organic hollow porous silica compared to V-SiO2 as core. In addition, core-shell structure obtained from CN-SiO2NH-SiO2 tend to be changed into hollow porous structure in alkaline condition on account of differential selective etching of functional groups strategy.

The Preparation and Characterization of Tourmaline-Containing Functional Copolymer p (VST/MMA/BA)

Tourmaline was modified with vinyl triethoxysilane containing double bond to prepare the polymerizable organic vinylsiliconoxyl tourmaline (VST) and then copolymerized with methyl methacrylate (MMA) and butyl acrylate (BA) to produce the tourmaline-containing functional copolymer p (VST/MMA/BA). The structures and morphologies of VST and p (VST/MMA/BA) copolymer were characterized by IR, SEM, and EDX. The experimental results indicated that tourmaline was introduced into the copolymer via surface modification and the tourmaline-containing functional copolymer was obtained by a copolymerization process with MMA and BA. The prepared p (VST/MMA/BA) copolymer displayed excellent storage stabilities, high far-infrared radiation and negative ion releasing performances, and good mechanical properties.

Preparation and Surface Modification of SiO2 Particles Used in Electronic Ink

In order to improve the surface properties of SiO2 particles, SiO2 particles were modified by vinyl triethoxysilane, SiO2 particles and vinyl triethoxysilane modified SiO2 particles were characterized by FTIR, SEM and XRD techniques. The results showed that vinyl triethoxysilane has been successfully grafted onto SiO2 particles and basically there are no changes in the size of SiO2 particles before and after the modification by vinyl triethoxysilane. XRD results show that the synthesized SiO2 particles have certain crystallinity.