Trimethylopropane Trimethacrylate Research Articles

Further discussion on the reaction behaviour of triallyl isocyanurate in the UV radiation cross-linking process of polyethylene: a theoretical study.

Further theoretical investigation on the reaction behaviour of triallyl isocyanurate (TAIC) in the UV radiation cross-linking process of polyethylene (PE) is accomplished by density functional theory for high voltage cable insulation materials. The reaction potential energy information of the 13 reaction channels at B3LYP/6–311 + G(d,p) level are identified. These have been explored that the TAIC take part in the reaction behaviour on ground state during UV radiation cross-linking process and TAIC intra-molecular isomerization reaction itself. In addition, the results show that the effect of multiplication and acceleration for the cross-linking reaction of trimethylopropane trimethacrylate (TMPTMA) would be better than that of TAIC. It has further clarified the reasons why UV radiation cross-linking reaction of PE had been initiated by benzophenone (Bp), and the TAIC or TMPTMA needed to take part. The results obtained in the present study could directly guide both the optimization of UV radiation cross-linking PE process and the development of the insulation material of high-voltage cable in real application.

Enhancement effect of trimethylopropane trimethacrylate on electron beam irradiated acrylonitrile butadiene styrene (ABS)

This paper reports the effect of electron beam irradiation on physico-mechanical properties of trimethylopropane trimethacrylate (TMPTMA) added acrylonitrile–butadiene–styrene (ABS) blends. The increasing of TMPTMA amount has gradually induced the gel content of all ABS samples. This is because incorporation of TMPTMA promotes formation of crosslinking networks in ABS matrix through releasing of monomer free radicals when irradiated. The results of hot set test also revealed that higher irradiation dosage required ≥ 6 phr TMPTMA to promote higher degree of crosslinking networks. The addition of TMPTMA also gradually improved the tensile strength and elongation at break of all ABS blends due to the existing of crosslinked chains. However, higher electron beam irradiation (≥ 200 kGy) has significantly reduced the tensile strength and elongation at break of all ABS samples due to chain-scissioning effect. The formation of crosslinking networks has induced the extendability of ABS matrix as evidenced in SEM observation. The crystallite size of deflection peak (110) also found to increase with low irradiation dosages.

Synergistic effect of SBS and trimethylopropane trimethacrylate (TMPTMA) on dynamically vulcanized SEBS/PP blends

ABSTRACTThe SEBS/PP thermoplastic vulcanizates (TPVs) were prepared by melt blending. Di‐tert‐butyl peroxide (DTBP) was used as the curing agent in combination with trimethylopropane trimethacrylate (TMPTMA) and poly(styrene‐b‐butadiene‐bstyrene) (SBS) as the coagents for the curing process. The synergistic effect of TMPTMA and SBS on the structure and properties of TPVs was studied by means of FT‐IR, DSC, torque rheometer, and universal testing machine. Both SEBS and PP crosslinked and the network structure formed under the participation of TMPTMA and SBS. Compared with the sole addition of the coagent, simultaneous loading of both TMPTMA and SBS could provide the TPVs with better solvent‐resistance and excellent mechanical properties. The crosslinking mechanism of the TPVs was also proposed. The slight lower value of Tm for the TPVs indicated the improved miscibility between PP and SEBS due to the crosslinking reaction. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44392.

Effectiveness of trimethylopropane trimethacrylate for the electron-beam-irradiation-induced cross-linking of polylactic acid

The purpose of this research was to investigate the effects of various loading levels of trimethylopropane trimethacrylate (TMPTMA) on the properties of polylactic acid (PLA) cross-linked via electron-beam irradiation. PLA was compounded with 3–5wt.% of TMPTMA to induce cross-linking upon subjection to electron-beam irradiation doses of 25–250kGy. The physical properties of the PLA samples were characterised by means of X-ray diffraction, gel fraction and scanning electron microscopy analyses on fractured surfaces after tensile tests. The presence of TMPTMA in PLA was found to effectively increase the crystallite size and gel fraction. However, higher loading levels of TMPTMA could compromise the properties of the PLA/TMPTMA samples, indicating that a larger amount of monomer free radicals might promote degradation within the substantially cross-linked amorphous phase. Irradiation-induced cross-linking in the samples could improve the cross-linking density while decreasing the elongation and interfering with the crystallisation. These effects are caused by the intensive irradiation-induced chain scission that is responsible for the deterioration of the mechanical and crystalline properties of the samples.

Combined Effects of Microwaves, Electron Beams and Polyfunctional Monomers on Rubber Vulcanization

Thispaperpresents comparative results obtained by conventional vulcanization with benzoyl peroxide (CV-BP), separate electron beam vulcanization (EB-V) and simultaneous electron beam and microwave vulcanization (EB+MW-V) applied to two kind of rubber samples: EVA (ethylene vinyl acetate) rubber-sample (EVA-sample) and EPDM (ethylene-propylene terpolymer) rubber-sample (EPDM-sample). The EVA-samples contain 61,54% EVA Elvax 260, 30.77% carbon black, 1.85% TAC (triallylcyanurate) polyfunctional monomer and 5.84% filler (zinc oxide, stearic acid, polyetylen glycol and antioxydant). The EPDM-samples contain 61.54% EPDM Nordel 4760, 30.77% carbon black, 1.85% TMPT (trimethylopropane trimethacrylate) polyfunctional monomer and 5.84% filler (zinc oxide, stearic acid, polyetylen glycol and antioxydant). The rubber samples designedfor different vulcanization methods were obtainedfrom raw rubber mixtures, as compressed sheets of 2 mm in the polyethylene foils to minimize oxidation. For EB and EB+MW treatments the sheets were cut in rectangular shape 0.15 x 0.15 m2. The physical properties of samples obtained by CV-BP, EV-V and EB+MW-V methods were evaluated by measuring the tearing strength, residual elongation, elongation at break, tensile strength, 300% modulus, 100% modulus, elasticity and hardness. The obtained results demonstrate an improvement of rubber several properties obtained by EB and EB+MW processing as compared to classical procedure using benzoyl peroxide.

Radiation grafting of styrene onto polypropylene fibres by a 10 MeV electron beam

The radiation-induced graft copolymerization is an effective method for modification of the chemical and physical properties of polypropylene. Graft copolymerization of styrene onto polypropylene fibers has been studied by simultaneous irradiation method, using a 10 MeV electron beam. Samples were irradiated in an environment of nitrogen gas. The effects of radiation dose and styrene concentration in methanol, on the grafting yield were investigated. The effects of polyfunctional monomer, i.e., trimethylopropane trimethacrylate (TMPTMA) and acid (sulfuric acid) on the grafting yield were also examined. The grafted samples were then sulfonated and allowed to react with solution of a basic dye. The samples were characterized by mechanical properties and thermal stability. The mechanical properties of the radiated samples were reduced and the grafted samples had lower mechanical properties.

Composite Microfiltration Membranes Imprinted with cAMP

AbstractComposite microfiltration membranes covered with a thin layer of molecularly imprinted polymer (MIP) selective to adenosine 3′:5′‐cyclic monophosphate (cAMP) were obtained and their separation properties were studied. MIP layers were prepared using photoinitiated copolymerization of dimethylaminoethyl methacrylate (DMAEM) as a functional monomer and trimethylopropane trimethacrylate (TRIM) as a crosslinker in the presence of cAMP as template in ethanol/water mixture. Blank membranes were prepared under the same conditions, but without cAMP. It was found out that pH of aqueous solution of the template has an effect on the binding of cAMP with MIP membranes. It was concluded that the ability of MIP membranes to bind cAMP is a result of both ionic interactions between charged dimethylamino groups of polymer matrix and the phosphorous residue of cAMP molecule and the specific shape of recognizing sites. These sites are complementary to cAMP in terms of three dimensional shape as well as correct position of functional groups involved in the template binding. This paper shows that the binding capability of MIP membranes can be adjusted by varying the values of degree of modification (DM). Atomic Force Microscopy (AFM) and Scanning Force Microscopy (SEM) were used to visualise surfaces and cross sections of membranes to gain better understanding in the analysis of MIP layer deposited on membranes.

Surface modified microfiltration membranes with molecularly recognising properties

Polyvinilidene fluoride (PVDF-phob and PVDF-phil) and polyethersulfone (PES) microfiltration membranes were surface modified with a thin layer of molecular imprinted polymer (MIP). This material is selective to adenosine 3:5-cyclic monophosphate (cAMP) via photoinitiated copolymerisation of 2-(dimethylamino)ethyl methacrylate as a functional monomer and trimethylopropane trimethacrylate as a cross-linker in the presence of cAMP in ethanol/water solutions. The specific and non-specific template binding of MIP during filtration of aqueous solutions of cAMP was studied for membranes with different degrees of modification. It was concluded that the ability of MIP membranes to bind cAMP is a result of both the specific size and shape of recognising sites in addition to the correct position of the functional groups involved in the template binding through ionic and hydrogen binding interactions. Profile imaging atomic force microscopy and scanning electron microscopy were used to visualise surfaces and cross-sections of MIP membranes. The main advantages of this approach for MIP membrane preparation are very fast MIP layer synthesis and the possibility to obtain MIP composite membranes by controlled deposition on different kind of polymeric supports. Atomic force microscopy in conjunction with the coated colloid probe technique has been used to measure interactions between a silica sphere coated with imprinted polymer and porous supports.

Characterization of molecularly imprinted composite membranes using an atomic force microscope

AbstractAtomic force microscopy (AFM) has been used to investigate the surface structure of molecularly imprinted polyethersulphone (PES) membranes and to quantify pore size and surface roughness. Molecularly imprinted polymeric (MIP) membranes were developed using photoinitiated copolymerization of 2‐hydroxyethyl methacrylate as functional monomer and trimethylopropane trimethacrylate as crosslinker in the presence of adenosine 3′ : 5″‐cyclic monophosphate as template, followed by deposition of a MIP layer on the surface of (PES) microfiltration membranes. Atomic force microscopy images clearly indicate that a consistent increase in the degree of modification leads to a systematic decrease in pore size and an increase in surface roughness. These results show a good correlation with the filtration data of cAMP solutions. Thus, it was shown that direct AFM quantification of key parameters of imprinted membrane structure provide useful guidelines for the development of novel MIP composite membranes. Copyright © 2002 John Wiley & Sons, Ltd.

Effect of co‐promoter and secondary monomer on shrinkage control of unsaturated polyester (UP)/styrene (St)/low‐profile additive (LPA) systems cured at low temperatures

AbstractThe shrinkage of unsaturated polyester (UP)/styrene (St) resins cured at low temperatures can be reduced by the presence of low‐profile additives (LPAs). It is believed that the reaction‐induced phase separation and the polymerization shrinkage in both the LPA‐rich and UP‐rich phases result in the formation of microvoids, which partially compensates the resin shrinkage. The relative reaction rate in the two phases plays an important role in shrinkage control. In this study, secondary monomers [such as divinylbenzene (DVB) and trimethylopropane trimethacrylate (TMPTMA)] and a co‐promoter, 2,4‐pentandione (2,4‐P), were added into the UP/St/LPA resin systems to investigate their effect on the shrinkage control of resins cured at low temperatures. Dilatometery results showed that the addition of both TMPTMA and 2,4‐P resulted in an earlier volume expansion during curing and better shrinkage control. The phase separation, reaction kinetics, and viscosity changes in the LPA‐rich and UP‐rich phases during curing were also investigated. The results confirmed that the increased reaction rate in the LPA‐rich phase led to an earlier formation of microvoids and, consequently, less volume shrinkage of the cured resin. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 738–749, 2001

Macroporous photopolymer frits for capillary electrochromatography

Macroporous polymer frits have been fabricated in fused-silica capillaries by the UV photopolymerization of a solution of glycidyl methacrylate and trimethylopropane trimethacrylate. This in situ preparation is a simple, rapid, and reproducible process. The frit can be placed at any desired position along the column. Photopolymer frits can withstand the short exposure to a high pressure (over 6000 psi). Bubble formation is no observed to occur with these frits under our experimental conditions. By choice of porogens, it is possible to control the porous properties. The use of such frits in capillaries to retain particles of chromatographic packing has been demonstrated to be stable and robust with continuous operation over 3 days.

Processing and properties of high‐temperature creep‐resistant PVC plastisols

AbstractThe effect of the use of an unsaturated reactive plasticizer trimethylopropane trimethacrylate, TMPTMA, on the structure and the creep behavior of poly(vinyl chloride), PVC, plastisols has been investigated as part of a program to develop a high‐temperature creep‐resistant liner material. The crosslinking reaction was initiated with a peroxide. The effect on the network structure of using a free radical scavenger in the formulation has also been studied. Gel yield and grafted PVC content in the gel increase with increased TMPTMA content in the plastisol. However, the residual unsaturation of TMPTMA decreases with increase of TMPTMA content. Introduction of TMPTMA into the plastisol promotes the creep resistance at high temperatures, and the effectiveness increases when there are PVC molecules grafted onto TMPTMA networks.