scholarly journals Synthesis and Properties of Adhesive Polymer-Methylmethacrylate Materials

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Ulyana Khromiak ◽  
Volodymyr Levytskyi ◽  
Kateryna Stepova ◽  
Andry Tarnawsky
Keyword(s):  
Polymer Matrix ◽  
Surface Hardness ◽  
Monomer Conversion ◽  
Adhesive Bond ◽  
Softening Temperature ◽  
High Reactivity ◽  
Technological Parameters ◽  
High Adhesion ◽  
Rate Of Polymerization ◽  
Monomer Content

Kinetics of emulsion polymerization of hydrophilic vinyl monomers in the presence of polyvinylpyrrolidone and technological principles of their synthesis are determined. Reasonable technological parameters in the synthesis of copolymers are determined. Physicochemical properties of the synthesized copolymers (surface tension, the size of latex particles, and pH) are determined. Synthesized graft copolymers were used to create high-adhesion polymer-monomer compositions. These compositions have high reactivity at room temperature. It can be regulated by the nature of the polymer matrix and the introduction of comonomers and fillers due to the influence of physicochemical factors on the process of polymer formation. The rate of polymerization and the degree of monomer conversion largely depend on the nature of the polymer matrix. The highest polymerization rate and the maximum degree of conversion are observed when using a copolymer of polyvinylpyrrolidone and polymethylmethacrylate. Materials based on the developed compositions are characterized by a low residual monomer content and high operational properties, such as surface hardness, Vicat softening temperature, and adhesive bond strength to supports of different nature.

scholarly journals Influence of Gating System Parameters of Die-Cast Molds on Properties of Al-Si Castings

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3755
Author(s):  
Štefan Gašpár ◽  
Tomáš Coranič ◽  
Ján Majerník ◽  
Jozef Husár ◽  
Lucia Knapčíková ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Computer Modelling ◽  
Permanent Deformation ◽  
Surface Hardness ◽  
Technological Parameters ◽  
Inlet System ◽  
Die Cast ◽  
Key Factor ◽  
Fine Grained Structure ◽  
Design Solutions

The resulting quality of castings indicates the correlation of the design of the mold inlet system and the setting of technological parameters of casting. In this study, the influence of design solutions of the inlet system in a pressure mold on the properties of Al-Si castings was analyzed by computer modelling and subsequently verified experimentally. In the process of computer simulation, the design solutions of the inlet system, the mode of filling the mold depending on the formation of the casting and the homogeneity of the casting represented by the formation of shrinkages were assessed. In the experimental part, homogeneity was monitored by X-ray analysis by evaluating the integrity of the casting and the presence of pores. Mechanical properties such as permanent deformation and surface hardness of castings were determined experimentally, depending on the height of the inlet notch. The height of the inlet notch has been shown to be a key factor, significantly influencing the properties of the die-cast parts and influencing the speed and filling mode of the mold cavity. At the same time, a significant correlation between porosity and mechanical properties of castings is demonstrated. With the increasing share of porosity, the values of permanent deformation of castings increased. It is shown that the surface hardness of castings does not depend on the integrity of the castings but on the degree of subcooling of the melt in contact with the mold and the formation of a fine-grained structure in the peripheral zones of the casting.

Effect of Rosin Ester on Water-Resistant Adhesion Oximized RTV-1 Silicone Rubber Sealant

2010 ◽  
Vol 150-151 ◽  
pp. 626-629
Author(s):  
Sui Lian Luo ◽  
Yang Shan Hu ◽  
Guang Shi ◽  
Hui Ming Pan
Keyword(s):  
Silicone Rubber ◽  
Adhesive Bond ◽  
Hot Water ◽  
Adhesive Failure ◽  
Good Adhesion ◽  
Pentaerythritol Ester ◽  
High Adhesion ◽  
Rosin Ester

It is necessary to improve the adhesion of the cured rubber to a substrate as it is used extensively. It is well known that an improvement in adhesion can be realized by incorporating in the composition a sliane or siloxane. Although the composition provides good adhesion to many kinds of substrates, it has been found that the adhesive bond degrades rapidly under wet conditions. To be solved it, rosin eater was incorprated in the silcone ruber in the paper. Increasing the content of rosin ester could induce a relative high adhesion in hot water. Moreover, when the content of modified rosin pentaerythritol ester was above 4.5 phr, the immersion days in hot water before adhesive failure occured were three times than that of non-additive rosin esters.

scholarly journals Production of modified adhesive composites based on EVA and modified PE

2020 ◽  
pp. 45-47
Author(s):  
M. D. Sizova ◽  
A. N. Zelenetsky ◽  
V. Ya. Ivolgin
Keyword(s):  
Maleic Anhydride ◽  
Polymer Matrix ◽  
Morphological Changes ◽  
Adhesive Properties ◽  
Adhesion Properties ◽  
High Adhesion

An adhesive based on EVA and LDPE is developed which can be used up to 60°C. It was modified by polyisocyanate fragments of a grafted and reticulate nature for structural and morphological changes of the polymer matrix and improvement of physical, mechanical and adhesive properties. For additional compatibilization of the components, LDPE modified with maleic anhydride (MA) was used. High adhesion properties of the obtained composites were confirmed.

Surface hardening of SUS304 by irradiation with a KrF excimer laser in SiH4 gas ambient

1990 ◽  
Vol 5 (2) ◽  
pp. 265-270 ◽  
Author(s):  
Koji Sugioka ◽  
Hideo Tashiro ◽  
Koichi Toyoda ◽  
Eiichi Tamura ◽  
Keigo Nagasaka
Keyword(s):  
Excimer Laser ◽  
Surface Hardening ◽  
Continuous Distribution ◽  
Surface Hardness ◽  
Laser Pulses ◽  
High Concentration ◽  
Laser Fluences ◽  
High Adhesion ◽  
Krf Excimer Laser ◽  
Si Films

Surface hardening of SUS304 resulting from the process of doping and deposition of Si by irradiation of a KrF excimer laser beam in a SiH4 gas ambient is investigated, and variations of the surface hardness are examined for different numbers of laser pulses and the laser fluences. The hardening is due to Si incorporation in high concentration. The continuous distribution of Si atoms across the surface layer suggests that a very high adhesion strength of the deposited Si films can be formed. The specific process for surface modification is referred to as laser implant-deposition (LID).

scholarly journals Estimating the effect of aqueous cationic latex from the class of thermal elastic plastics on the properties of bitumen emulsions

2021 ◽  
Vol 4 (6(112)) ◽  
pp. 14-22
Author(s):  
Valeriy Zhdaniuk ◽  
Victoria Novakovska
Keyword(s):  
Mechanical Properties ◽  
Aqueous Phase ◽  
Elevated Temperatures ◽  
Softening Temperature ◽  
Physicochemical Characteristics ◽  
Interphase Surface ◽  
Technological Parameters ◽  
Modified Bitumen ◽  
Cationic Latex ◽  
Bitumen Emulsions

To produce cationic bitumen emulsions, bitumen is used, whose penetration is not lower than 90 mm-1. Such bitumen has a small plasticity interval, which leads to a deterioration in its heat resistance at elevated temperatures and narrows the scope of application of emulsions based on it. Based on the review of emulsion modification methods, the modification has been proposed that involves mixing the finished bitumen emulsions with aqueous cationic latex. The process of interaction between a bituminous emulsion and an aqueous cationic latex has been considered. A mechanism for the disintegration of the modified bitumen emulsion on the surface of mineral materials was proposed. The emulsifiers have been selected and the composition of the aqueous phase has been chosen based on the analysis of surface tension isotherms. The influence of the modification on the properties of bitumen emulsions was investigated. It was established that the main physicochemical characteristics of the interphase surface accept similar values for the aqueous phase and emulsions based on it. It has been proven that the introduction of aqueous cationic latex quite moderately affects the basic physical-mechanical properties of emulsions, which makes it possible not to change the main technological parameters when using them. It was established that increasing the concentration of the polymer in the emulsion has a positive effect on the physical-mechanical properties of the binder. With an increase in the concentration of the polymer to 6 % the softening temperature increases by 16 °C, elasticity is 74 %, and the holding capacity at minus 25 °C is approaching 100 %. Improving the physical-mechanical properties of residual binder as a result of emulsion modification could increase the durability of layers in a roadbed based on bitumen emulsions and expand the scope of their application in the construction and repair of motorways

scholarly journals The Dependence of Cocksfoot Productivity of Liming and Nitrogen Application and the Assessment of Qualitative Parameters and Environmental Impact Using Biomass for Biofuels

2020 ◽  
Vol 12 (19) ◽  
pp. 8208
Author(s):  
Gintaras Šiaudinis ◽  
Algirdas Jasinskas ◽  
Danutė Karčauskienė ◽  
Egidijus Šarauskis ◽  
Kristina Lekavičienė ◽  
...  
Keyword(s):  
Positive Impact ◽  
Combustion Process ◽  
Calorific Value ◽  
Softening Temperature ◽  
Dry Mass ◽  
Fertilization Rate ◽  
Raw Material ◽  
Utilization Efficiency ◽  
Nitrogen Efficiency ◽  
Technological Parameters

In order to evaluate the liming and nitrogen efficiency of cocksfoot (Dactylisglomerata L.) productivity, a field experiment was performed in Western Lithuania’s naturally acidic Retisol area (55°43′ N, 21°27′ E). Based on seven years of research data, dry mass (DM) yield (including first and second cuttings) reliably varied depending on the growing year, from 4.57 to 7.34 t ha−1. The most significant and positive impact on DM yield was obtained by the application of higher liming (6.0 t ha−1 CaCO3) and nitrogen (120 kg ha−1) rates. Liming utilization efficiency (LUE) was affected by the year of growth (although not always significantly), with a 6.0 t ha−1 CaCO3 liming rate and nitrogen fertilization. Nitrogen utilization efficiency (NUE) varied depending on the growing year and N fertilization rate. One of the most effective solutions for improving cocksfoot biomass is to prepare pressed granulated biofuel, which is potentially a good quality raw material for the direct combustion process. The execution and evaluation of technological parameters and properties of produced pellets revealed that cocksfoot pellet humidity reached 10.0% ± 0.6%, whereas pellet density was sufficiently high, and reached 983.8 ± 22.9 kgm−3 DM. The lower calorific value of cocksfoot pellets reached 17.7 MJkg−1. Ash content after pellet burning was relatively high, reaching 7.0–7.6%. Pellet ash melting temperatures were sufficiently high, with ash softening temperature (ST) reaching 1065 °C. Determined emissions of harmful gases from the burning of cocksfoot pellets (CO2, CO, SO2, NOx and unburnt hydrocarbons CxHy) did not exceed the permissible limits.

Structure and properties of composites based on polyphenylene sulfide reinforced with Al-Cu-Fe quasicrystalline particles

2017 ◽  
Vol 31 (7) ◽  
pp. 882-895 ◽  
Author(s):  
DI Chukov ◽  
AA Stepashkin ◽  
VV Tcherdyntsev ◽  
LK Olifirov ◽  
SD Kaloshkin
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Polymer Matrix ◽  
Resistance Index ◽  
Softening Temperature ◽  
Polyphenylene Sulfide ◽  
Mechanical And Thermal Properties ◽  
Structure And Properties ◽  
Properties Of Composites

Structural, mechanical, and thermal properties of polyphenylene sulfide (PPS) filled with Al-Cu-Fe quasicrystals particles were studied. It was shown that the introducing of quasicrystalline fillers into the polymer matrix results in the increase in Young’s modulus, hardness, and toughness of the polymer. Quasicrystalline fillers can improve thermal properties of PPS, including heat resistance index, Vicat softening temperature, thermal diffusivity, and thermal conductivity.

scholarly journals Long-Term Surface Hardness and Monomer Conversion of a Nanofilled and a Microhybrid Composite Resin

2013 ◽  
Vol 14 (5) ◽  
pp. 876-882 ◽  
Author(s):  
Mateus Rodrigues Tonetto ◽  
Matheus Coelho Bandéca ◽  
José Roberto Cury Saad ◽  
Edson Alves de Campos ◽  
Fernanda Ferreira Jassé ◽  
...  
Keyword(s):  
Composite Resin ◽  
Artificial Saliva ◽  
Hydrolytic Degradation ◽  
Metallic Matrix ◽  
Surface Hardness ◽  
Storage Period ◽  
Hardness Test ◽  
Monomer Conversion ◽  
Bottom Surface

ABSTRACT Objective This study aims to evaluate the degree of conversion (DC) and hydrolytic degradation through the Vickers hardness test (HV) of a nanofilled (FiltekTM Z-250, 3M) and a microhybrid (FiltekTMSupreme-XT, 3M) composite resin. Materials and methods Eight disk-shaped specimens (4 mm diameter × 2 mm thick, ISO 4049) of each material were prepared for each test. Composites were inserted into single increment in a metallic matrix and light-cured for 40 seconds. VH readings were performed for each specimen at predetermined intervals: immediately after polymerization (control), 1, 2, 3, 7, 14, 21, 30 and 180 days. After curing, initial hardness measurements were performed and the specimens were immersed in artificial saliva at 37°C. For DC (%), specimens were ground, pressed with KBr and analyzed by FT-IR spectrophotometer. Results Student t-test showed that there was no difference between the resins for DC (p = 0.252). ANOVA analysis revealed that Z-250 VH means were all greater than S-XT, for both top and bottom surfaces, whatever the storage-period in artificial saliva (p < 0.001). After 180 days of storage, the hardness obtained for S-XT was similar with that at the baseline, for both top and bottom surfaces. While for Z-250 hardness was not significantly different from baseline only for top surface, but there was a significant decrease observed in hardness for bottom surface. Conclusion The materials tested showed no evidence of hydrolytic degradation in a significant way, in a 6-month storagetime in artificial saliva. Nanofilled resin presents a monomer conversion comparable to the conventional microhybrid. How to cite this article Jassé FF, Borges CHB, Tonetto MR, de Souza Rastelli AN, Bagnato VS, de Campos EA, Bandeca MC, Saad JRC. Long-Term Surface Hardness and Monomer Conversion of a Nanofilled and a Microhybrid Composite Resin. J Contemp Dent Pract 2013;14(5):876-882.

scholarly journals Chiral 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD)-Catalyzed Stereoselective Ring-Opening Polymerization of rac-Lactide: High Reactivity for Isotactic Enriched Polylactides (PLAs)

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2365 ◽  
Author(s):  
Qaiser Mahmood ◽  
Guangqiang Xu ◽  
Li Zhou ◽  
Xuanhua Guo ◽  
Qinggang Wang
Keyword(s):  
Molecular Weight ◽  
Ring Opening ◽  
Kinetic Studies ◽  
Monomer Conversion ◽  
Ring Opening Polymerization ◽  
High Reactivity ◽  
Chiral Hplc ◽  
Nmr Spectrum ◽  
Molecular Weight Distributions ◽  
A Chain

Chiral 4,8-diphenyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (DiPh-TBD) was synthesized and applied to a ring-opening polymerization of rac-lactide (rac-LA). The chiral DiPh-TBD promoted the synthesis of isotactic enriched polylactides (PLAs) with controlled molecular weight and narrow molecular weight distributions under mild, metal-free conditions. When the [rac-LA]/[Cat.] ratio was 100/1, full monomer conversion was achieved within only 1 min and a moderate probability of 0.67 meso dyads (Pm) was obtained at room temperature. A chain-end control mechanism (CEC) was found to be responsible for the isoselectivity based on the homodecoupled 1H NMR spectrum, the chiral HPLC measurement, and kinetic studies.

On mechanical and surface properties of electro-active polymer matrix-based 3D printed functionally graded prototypes

2020 ◽  
pp. 089270572090767 ◽  
Author(s):  
Ravinder Sharma ◽  
Rupinder Singh ◽  
Ajay Batish
Keyword(s):  
3D Printing ◽  
Mechanical Testing ◽  
Surface Properties ◽  
Polymer Matrix ◽  
Mechanical Performance ◽  
Surface Hardness ◽  
Functionally Graded ◽  
Density Level ◽  
Fused Deposition ◽  
3D Printed

This research article reports the mechanical and surface properties of 3D printed electro-active polymer (EAP) matrix-based functionally graded prototypes with fused deposition modeling. The standard tensile specimens (per ASTM D-638-type IV) have been 3D printed using in-house developed feedstock filament. The EAP, polyvinyl diene fluoride (PVDF)-based matrix, has been used with the reinforcement of barium titanate (BT) and graphene (Gr) in this study. The fixed proportion of the polymer matrix composite comprising PVDF (78 wt%) + Gr (2 wt%) + BT (20 wt%) has been selected for 3D printing of smart polymer matrix. The results of mechanical testing suggested that the 3D printing of parts performed at 50 mm/s infill speed; infill angle of 45° at maximum density level (100%) has shown better mechanical strength (peak strength 42.98 MPa and break strength 40.70 MPa). The result of surface hardness has shown strong correlation with observed tensile properties. The microphotographs of fractured surfaces revealed that the parts fabricated at highest density have minimum porosity, resulting into better mechanical performance as compared to parts fabricated at lower density level. Further the results of mechanical testing have been supported by 3D rendered images and surface roughness profile.

Sign in / Sign up

Export Citation Format

Share Document