Controlling the Length of Microtubules by Manipulating Their Polymerization Condition

2018 ◽  
Vol 88 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Arif Md. Rashedul Kabir ◽  
Akira Kakugo
Keyword(s):  
Polymerization Condition

scholarly journals Synthesis and Conductivity Studies of Poly(Methyl Methacrylate) (PMMA) by Co-Polymerization and Blending with Polyaniline (PANi)

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1939
Author(s):  
Helyati Abu Hassan Shaari ◽  
Muhammad Mahyiddin Ramli ◽  
Mohd Nazim Mohtar ◽  
Norizah Abdul Rahman ◽  
Azizan Ahmad
Keyword(s):  
Methyl Methacrylate ◽  
Mechanical Stability ◽  
Chemical Properties ◽  
Cost Effective ◽  
Poly Methyl Methacrylate ◽  
Conducting Materials ◽  
Potential Applications ◽  
Polymerization Condition ◽  
Physical And Chemical ◽  
And Chemical Properties

Poly(methyl methacrylate) (PMMA) is a lightweight insulating polymer that possesses good mechanical stability. On the other hand, polyaniline (PANi) is one of the most favorable conducting materials to be used, as it is easily synthesized, cost-effective, and has good conductivity. However, most organic solvents have restricted potential applications due to poor mechanical properties and dispersibility. Compared to PANi, PMMA has more outstanding physical and chemical properties, such as good dimensional stability and better molecular interactions between the monomers. To date, many research studies have focused on incorporating PANi into PMMA. In this review, the properties and suitability of PANi as a conducting material are briefly reviewed. The major parts of this paper reviewed different approaches to incorporating PANi into PMMA, as well as evaluating the modifications to improve its conductivity. Finally, the polymerization condition to prepare PMMA/PANi copolymer to improve its conductivity is also discussed.

scholarly journals Impact of refrigeration on the surface hardness of hybrid and microfilled composite resins

2009 ◽  
Vol 20 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Fernando Henrique Ruppel Osternack ◽  
Danilo Biazzetto de Menezes Caldas ◽  
Rodrigo Nunes Rached ◽  
Sérgio Vieira ◽  
Jeffrey A. Platt ◽  
...  
Keyword(s):  
Room Temperature ◽  
Surface Hardness ◽  
In Vitro Study ◽  
Knoop Hardness ◽  
Composite Resins ◽  
Bottom Surface ◽  
Steel Mold ◽  
Polymerization Condition ◽  
Post Hoc

This in vitro study evaluated the Knoop hardness of the composite resins Charisma® (C) and Durafill VS® (D) polymerized in 3 different conditions: at room temperature (A) (23 ± 1°C); refrigerated at 4 ± 1°C and immediately photo-activated after removal from the refrigerator (0); and, refrigerated at 4 ± 1°C and photo-activated after a bench time of 15 min at room temperature (15). One hundred and twenty specimens (4 mm diameter and 2 mm depth) were made using a stainless steel mold and following manufacturer's instructions. All specimens were tested immediately after polymerization (I) and after 7 days of water storage in the dark at room temperature (7d). The data were subjected to ANOVA and post-hoc Tukey's test (a=0.05). On the top surface, CAI was statistically similar to C15I and DAI to D15I (p>0.05). On the bottom surface, CAI presented higher hardness values when compared to COI and C15I (p<0.05). The D groups showed no significant differences (p>0.05) on the bottom surfaces for any tested polymerization condition. After 7 days of storage, the Knoop hardness decreased significantly (p<0.05) for groups C7d and D7d except for C07d, which was not different from COI at either surface (p>0.05). D07d showed higher Knoop hardness (p<0.05) values on the top surface when compared to the other groups.

Properties of Heterojunction of Si/Poly(3-methylthiophene) as a Function of Polymerization Condition

1993 ◽  
Vol 32 (Part 1, No. 1A) ◽  
pp. 189-194 ◽  
Author(s):  
Hiroshi Kokado ◽  
Fumio Hosokawa ◽  
Katsuyoshi Hoshino
Keyword(s):  
Polymerization Condition

scholarly journals Influence of Monomer Composition in the Electron Beam Graft Polymerization Condition onto PET Fabrics

2018 ◽  
Vol 74 (7) ◽  
pp. 150-157
Author(s):  
Koji Miyazaki ◽  
Kouji Notoh ◽  
Takuya Honda ◽  
Zhanglian Xu ◽  
Kazumasa Hirogaki ◽  
...  
Keyword(s):  
Electron Beam ◽  
Graft Polymerization ◽  
Monomer Composition ◽  
Polymerization Condition

The Effect of Fiber Position and Polymerization Condition on the Flexural Properties of Fiber-Reinforced Composite

2004 ◽  
Vol 5 (2) ◽  
pp. 14-26 ◽  
Author(s):  
Lippo V.J. Lassila ◽  
Pekka K. Vallittu
Keyword(s):  
Flexural Strength ◽  
Glass Fibers ◽  
Flexural Modulus ◽  
Flexural Properties ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Monomer Content ◽  
Light Curing ◽  
Polymerization Condition

Abstract The aim of this study was to investigate the influence of the position of the fiber rich layer on the flexural properties of fiber-reinforced composite (FRC) construction. In addition, the total residual monomer content of FRC was quantitatively determined to find out the difference of the effectiveness of two types of light-curing units using liquid chromatography (HPLC). Unidirectional continuous E-glass FRC and hybrid particulate filler composite resins were used in the fabrication of test specimens. Four different positions of the FRC layer were used: compression, neutral, tension, and vertical side position. A three-point bending test (ISO 10477) was performed to measure the flexural properties of the specimens. Position of the FRC layer had a significant effect on the flexural strength (p<0.001, ANOVA). Also, the type of light-curing device had an effect on flexural strength (p<0.001). Specimens with FRC positioned on the compression side showed flexural strength of approximately 250 MPa, whereas FRC positioned on the tension side showed strength ranging from 500 to 600 MPa. Mean flexural modulus with FRC placed horizontally ranged between 9-12 GPa; no significant difference was found between these groups. However when fiber reinforcement was positioned vertically, the flexural modulus raised up to 16 GPa. Specimens with 24 vol% glass fibers contained 52% less residual monomer than specimens without glass fibers. The monomer content was lower in specimens polymerized with the curing device with higher polymerization temperature. In order to optimize flexural strength of low fiber volume fraction, the fibers should be placed at the tension side of the specimen. Citation Lassila LVJ, Vallittu PK. The Effect of Fiber Position and Polymerization Condition on the Flexural Properties of Fiber-Reinforced Composite. J Contemp Dent Pract 2004 May;(5)2:014-026.

The Mechanical Properties of Low Cis-Butadiene Modified HIPS

2013 ◽  
Vol 744 ◽  
pp. 400-402
Author(s):  
Hui Ming Yao ◽  
Yong Liang Yuan ◽  
Xiao Yun Liu ◽  
Sheng Qiang Qian ◽  
Jian Long Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Particle Size ◽  
Impact Strength ◽  
Elongation At Break ◽  
Polymerization Condition

In this paper, low cis-butadiene (LCPB) is used in the process of polymerization of HIPS to study the influence of the polymerization condition on the particle size of rubber and mechanical property. It can be discovered from the study that the particle size was increased from 300nm to 500nm with the decreasing stir. The test of mechanical property shows that with the increase of content of rubber, elongation at break and impact strength on cantilever increase, but stretching strength decreases. On condition of 100 rpm, when the content of rubber increases from 3% to 9%, elongation at break increases from 21.9% to 25.0%, stretching strength decreases from 30.5 MPa to 23.9 MPa, and the cantilever impact strength increases from 5.4KJ/m2 to 9.3KJ/m2. On condition of 200 rpm, when the content of rubber increases from 3% to 9%, elongation at break increases from 21.4% to 29.1%, stretching strength decreases from 28.7 MPa to 20.8 MPa, and the cantilever impact strength increases from 5.2KJ/m2 to 8.1KJ/m2. Keywords: HIPS, mechanical properties, morphologies, T117 initiation

Studies on microcapsules. VI. Effect of variations in polymerization condition on microcapsule size

1970 ◽  
Vol 48 (13) ◽  
pp. 2047-2051 ◽  
Author(s):  
Yoshimichi Shigeri ◽  
Masumi Koishi ◽  
Tamotsu Kondo ◽  
Motoharu Shiba ◽  
Suiichi Tomioka
Keyword(s):  
Monomer Concentration ◽  
Degree Of Polymerization ◽  
Interfacial Polycondensation ◽  
Polymerization Condition

The effect of variations in polymerization condition on the size of microcapsules prepared by the interfacial polycondensation method was studied. Factors lowering the rate and degree of polymerization, such as a decrease in temperature or monomer concentration, were found to increase the microcapsule size. A mechanism was proposed for the formation of large microcapsules in the polycondensation step.

scholarly journals The First Synthesis of Periodic and Alternating Glycopolymers by RAFT Polymerization: A Novel Synthetic Pathway for Glycosaminoglycan Mimics

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 70 ◽  
Author(s):  
Masahiko Minoda ◽  
Tomomi Otsubo ◽  
Yohei Yamamoto ◽  
Jianxin Zhao ◽  
Yoshitomo Honda ◽  
...  
Keyword(s):  
Chain Transfer ◽  
Binding Assay ◽  
Raft Polymerization ◽  
Lectin Binding ◽  
Feed Ratio ◽  
Controlled Synthesis ◽  
Reversible Addition ◽  
Monomer Feed ◽  
Polymerization Condition ◽  
Monomer Feed Ratio

This study concerned the controlled synthesis of periodic glycopolymers by reversible addition-fragmentation chain transfer (RAFT) copolymerization. To this end, maltose- and lactose-substituted vinyl ethers (MalVE and LacVE, respectively) and maltose-substituted maleimide (MalMI) were newly synthesized. RAFT copolymerization of MalVE and ethyl maleimide (EtMI) (monomer feed ratio: MalVE:EtMI = 1:1) afforded periodic glycopolymers (poly(MalVE-co-EtMI)) consisting of major parts of alternating structure (-(MalVE-EtMI)n-) and a small part of consecutive sequences of EtMI (–EtMI-EtMI-). Occurrence of the latter sequences was caused by the homopolymerizability of maleimide under the present polymerization condition, and the formation of the consecutive sequences of EtMI was successfully suppressed by varying the monomer feed ratio. RAFT copolymerization of LacVE and EtMI was also found to proceed and similarly yielded periodic glycopolymers (poly(LacVE-co-EtMI)). Moreover, RAFT copolymerization of LacVE and MalMI (monomer feed ratio: LacVE:MalMI = 1:1) was performed to give copolymers (poly(LacVE-co-MalMI)) having composition ratio of LacVE/MalMI ≈ 36/64. The resultant periodic glycopolymers poly(MalVE-co-EtMI) and poly(LacVE-co-EtMI) were subjected to lectin binding assay using concanavalin A and peanut agglutinin, exhibiting the glycocluster effect. Moreover, these glycopolymers obtained from the copolymerization of VE and MI were found to be non-cytotoxic.

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