scholarly journals Properties of Emulsion Paint with Modified Natural Rubber Latex/Polyvinyl Acetate Blend Binder

2021 ◽  
Vol 12 (1) ◽  
pp. 296
Author(s):  
Bahruddin Ibrahim ◽  
Zuchra Helwani ◽  
Ivan Fadhillah ◽  
Arya Wiranata ◽  
Joni Miharyono

The direct use of natural rubber latex (NRL) as a binder for emulsion paints did not produce emulsion paints with good opacity, washability resistance, and regulated touch drying time, even when mixed with polyvinyl acetate (PVAc). This study aimed to study the properties of opacity (hiding power), washability resistance, and set drying touch time of emulsion paint with a binder added from a mixture of modified natural rubber latex (NRL) and PVAc. NRL modifications included UV photodepolymerization with TiO2 catalyst and grafting copolymerization of methyl methacrylate and styrene (NRL-g-(MMA-co-St)). NRL was mixed with PVAC at ratios of 0/100; 15/85; 25/75; 35/65; 50/50; 100/0% w/w before being used as a binder for emulsion paint. Emulsion paint samples had different binder contents, namely 2, 4, 6, and 8% w/w. Tests on paint samples included opacity using a UV-Vis spectrophotometer (EASYSPEC safas Monaco), washability using the Digital BGD 526 Wet Abrasion Scrub Tester, and drying time set using the ASTM STP500 procedure. The results showed that the opacity (hiding power), washability resistance, and set drying touch time met the emulsion paint standards for all binder levels, except the 100% w/w modified NRL composition. The higher level of NRL in the binder causes these properties to decrease and become unstable. The best opacity (hidden power), washing resistance, and drying touch time were obtained on modified NRL with a concentration of 15% w/w. The binder content in the paint was around 4% w/w, with an opacity of about 1.78% abs, washing resistance of 12 times, and the set drying touch time to 80 min.

2008 ◽  
Vol 47-50 ◽  
pp. 1149-1152 ◽  
Author(s):  
Pranee Chumsamrong ◽  
Jakkarin Mondobyai

In order to study the potential of increasing the weather stability of natural rubber latex for use as a water-based contact adhesive, the natural rubber latex was modified by graft copolymerization with n-butyl acrylate (BA) and methyl methacrylate (MMA). The grafting reaction was carried out using emulsion polymerization at 60°C. Potassium persulfate was used to initiate polymerization. Four different weight percentage ratios of BA to MMA used in this work were 80:20, 70:30, 60:40 and 50:50. Percentage conversion of the monomer of all latexes prepared was ≥ 79.8 %. The grafting efficiency of grafted natural rubber latexes with a different monomer ratio tended to decrease with an increase of MMA. The adhesion property was characterized by 90° peel strength and 180° lap shear tests. The shear strength value of grafted natural rubber latexes increased with an increase of MMA content. The grafted latex with the monomer ratio of 50:50 possessed higher shear strength than natural rubber latex. The peel strength value of grafted natural rubber latexes seemed to lower than that of natural rubber latex. The weather stability of the modified latex was characterized using thermogravimetric analysis (TGA) and also the peel samples were left in the open air for 45 days before testing. The results showed that grafted natural rubber latex had a higher weather stability than natural rubber latex.


1958 ◽  
Vol 31 (3) ◽  
pp. 430-435 ◽  
Author(s):  
B. C. Sekhar

Abstract The peroxidic groups produced on the rubber hydrocarbon when oxygen is absorbed by ammonia-preserved latex are capable of initiating the graft polymerization of methyl methacrylate and other vinyl monomers, in the presence of suitable reducing agents. The products so formed contain only small proportions of unbound homopolymer. In the latex state, the products have a much higher wet gel strength and better film forming properties than materials of the same total vinyl polymer content prepared by other methods.


2016 ◽  
Vol 89 (1) ◽  
pp. 199-210 ◽  
Author(s):  
Aditjaya Jivapongvitoon ◽  
Panya Sunintaboon ◽  
Surapich Loykulnant ◽  
Krisda Suchiva

ABSTRACT Poly(methyl methacrylate)/polyethyleneimine (PMMA/PEI) core-shell nanoparticles were prepared by emulsifier-free emulsion polymerization. Micrographs from a scanning electron microscope and transmission electron microscope displayed their spherical shape with core-shell morphology in which PMMA was a core and PEI was a shell. The PMMA/PEI nanoparticles' ability to adsorb proteins from the serum of commercial low-ammonia preserved fresh field natural rubber latex was illustrated. The driving force for adsorption was proposed to be mainly via electrostatic interaction between the protonated amino groups of PEI chains on the nanoparticles' surface and phospholipids or protein molecules on NR particles. The reduction percentage was about 50%, depending on the content of PMMA/PEI nanoparticles and mixing time. For comparison, the protein reduction performance by the nanoparticles with two additional extracted serums, high-ammonia preserved concentrated NRL and Thai advanced preservative system NRL, which have different initial protein contents and pH values, was also investigated. The preliminary evaluation of PMMA/PEI nanoparticles' performance in sulfur-prevulcanized high-ammonia preserved concentrated NRL was also studied. Its corresponding sheet had lower extractable proteins by 50% and had tensile strength and elongation at break of 25.5 MPa and 715%, respectively.


2018 ◽  
Vol 4 (4) ◽  
pp. 78
Author(s):  
Irfan Naufal Abdurrahman ◽  
Heru Juhdi Gultom ◽  
Erma Desmaliana

ABSTRAKPanel Cross Laminated Timber (CLT) merupakan rekayasa kayu dengan penyusunan kayu dengan arah bersilangan 90  Material kayu yang digunakan yaitu kayu Sengon dan kayu Jabon. Pembuatan panel CLT menggunakan perekat Polyvinyl Acetate, Cross-linker, dan Lateks Karet Alam dengan perbandingan 1:1 untuk base dan 15% untuk katalisator. Tujuan dari penelitian ini, untuk mengetahui kinerja panel CLT kayu Sengon dan kayu Jabon terhadap beban tekan dan geser. Pembuatan panel CLT dilakukan dengan menggunakan kempa dingin dan dimensi panel CLT yang digunakan yaitu 950mm 950mm 120mm. Hasil pengujian eksperimental pada benda uji small clear, didapatkan bahwa kayu jabon dan kayu sengon masuk kedalam kelas kuat V. Kapasitas tekan panel CLT kayu Sengon lebih kuat dibandingkan CLT Jabon yaitu 12,196 MPa dengan defleksi 10,51 mm dan kapasitas tekan panel CLT Kayu Jabon 9,572 MPa dengan defleksi 2,67. Pada pengujian kuat geser Panel CLT kayu Sengon menghasilkan nilai kuat geser lebih baik dari pada CLT kayu Jabon sebesar 0,09 MPa, dan kuat geser CLT kayu Jabon 0,089 MPa. Kata kunci: cross laminated timber, perekat, kuat tekan, kuat geser, defleksi. ABSTRACTCross Laminated Timber (CLT) Panel Is wood engineering with wood’s arrangement cross direction 90°. Wood materials used Sengon and Jabon. Making CLT panels using Polyvinyl Acetate, Cross-linker, and Natural Rubber Latex adhesives with a ratio of 1:1 for base and 15% for catalyst. The purpose of this research is to know the performance of Sengon and Jabon wood CLT panels against press and shear load. CLT panel is made by used cold press processed and the CLT panel dimensions used is 950mm 950mm 120mm. The results of small clear test object, found that Jabon wood and sengon wood were included in the strong V class.The compressive capacity of Sengon wood CLT panel is stronger than Jabon CLT which is 12.196 MPa with 10.51 mm deflection and the compressive capacity of Jabon CLT panel is 9.572 MPa with a deflection of 2.67. The shear strength testing of Sengon wood CLT Panel produces better shear strength than Jabon wood. Shear strength Sengon’s CLT is 0.089 MPa and Jabon’s CLT is 0.128 MPa.Keywords: cross laminated timber, glue, compression strength, shear strength, deflection.


2015 ◽  
Vol 1123 ◽  
pp. 352-355 ◽  
Author(s):  
Hamidah Harahap ◽  
Elmer Surya ◽  
Indra Surya ◽  
Baharin Azahari ◽  
Hanafi Ismail

Alkanolamide-modifed kaolin was added into natural rubber latex (NRL) pre-vulcanization system at 70°C and the products were formed into films by coagulant dipping method. The dipped films then were dried at 120°C for 15 and 30 min. The effect of drying time on properties of NRL films such as crosslink density, tensile strength, tensile modulus, and elongation at break was observed in this study. Results showed that longer drying time improved the properties of NRL films due to the additional formation of crosslink process in the NRL films. The longer drying time swelled the particles more in matrix as confirmed by Scanning Electron Microscopy (SEM) micrograph.


Sign in / Sign up

Export Citation Format

Share Document