Polymeric Calcium Phosphate Cements Incorporated with Poly-γ-Glutamic Acid

2008 ◽  
Vol 396-398 ◽  
pp. 265-268
Author(s):  
Sung Soo Kim ◽  
Sung Jae Lee ◽  
Yong Sik Kim ◽  
Kwon Yong Lee
Keyword(s):  
Citric Acid ◽  
Calcium Phosphate ◽  
Glutamic Acid ◽  
Setting Time ◽  
Physiological Saline ◽  
Initial Setting Time ◽  
Calcium Phosphate Cements ◽  
Physiological Saline Solution ◽  
Biodegradable Poly ◽  
Initial Setting

Polymeric calcium phosphate cements (PCPC) derived from biodegradable poly-g-glutamic acid (g-PGA) were prepared in an attempt to improve the mechanical strength of calcium phosphate cement (CPC). The characteristics of the PCPCs were compared to those of cement incorporated with citric acid. The diametral tensile and compressive strengths of the CPC incorporated with g-PGA were significantly higher than that of cement incorporated with citric acid at equivalent concentrations (p<0.05). The maximal diametral tensile and compressive strengths of the CPC incubated for 1 week in physiological saline solution were approximately 18.0 and 50.0 MPa, respectively. However, the initial setting time of the PCPC was much slower than that of CPC incorporated with citric acid. The formation of ionic complexes between calcium ions and g-PGA was observed using FT-IR spectroscopy. Hydroxyapatite (HA) formation was retarded by g-PGA incorporation according to scanning electronic microscopy (SEM) and powder X-ray diffraction (XRD) observations.

Development of Bioresorbable Calcium-Phosphate Cements Hybridized with Gelatin Particles and their In Vivo Evaluation Using Pig’s Tibia Model

2014 ◽  
Vol 631 ◽  
pp. 397-401 ◽  
Author(s):  
Keishi Kiminami ◽  
Kento Matsuoka ◽  
Kohei Nagata ◽  
Toshiisa Konishi ◽  
Michiyo Honda ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Inositol Phosphate ◽  
Setting Time ◽  
Chelating Agent ◽  
Sulfate Solution ◽  
Initial Setting Time ◽  
Initial Setting ◽  
Preliminary Study ◽  
Surface Modified

Novel bioresorbable calcium-phosphate cement (CPC) with anti-washout property was developed by adding thermally cross-linked gelatin particles as pore generator into a CPC. The CPC was composed of α-tricalcium phosphate (α-TCP) and surface-modified hydroxyapatite (HAp) with inositol phosphate as a chelating agent (IP6-HAp). The bioresorbable CPC hybridized with gelatin particles was successfully fabricated by mixing the aqueous sodium chondroitin sulfate solution including Na2HPO4 and the pre-mixed powders composed of α-TCP (72 mass%), IP6-HAp (18 mass%), and the gelatin particles (10 mass%). The hybridized CPC paste showed initial setting time (IST) of 5 minutes and exhibited anti-washout property. Compressive strength after setting for 24 h reached to 4.2 MPa. An in vivo preliminary study using pig’s tibia model demonstrated that the hybridized CPC could be easily injected and set promptly without washout. In addition, no fragmentation in the specimens was observed after 8 weeks implantation. Moreover, a histological observation (Villanueva bone stain) revealed that almost 80% of the hybridized CPC specimens were resorbed and that immature bones were formed inside the specimens.

Effect of Citric Acid on Cement Hydration

2011 ◽  
Vol 393-395 ◽  
pp. 49-53 ◽  
Author(s):  
Bao Guo Ma ◽  
Jun Xiao ◽  
Hong Bo Tan
Keyword(s):  
Citric Acid ◽  
Cement Hydration ◽  
Setting Time ◽  
Initial Setting Time ◽  
Final Setting Time ◽  
Retarding Effect ◽  
Initial Setting ◽  
Flow Loss ◽  
Diffraction Peaks ◽  
Acid Dosage

Through the test of citric acid of cement paste, setting time and compression strength changes, and combined with XRD, SEM, discusses the influence of citric acid on cement hydration process. The results show that: citric acid can effectively increase the initial cement fluidity, when the content is exceed to 0.1%, the 60 min flow loss of increased gradually. Citric acid retarding effect increases with dosage, but there is a critical dosage, when the dosage is less than 0.1%, the initial setting time and final setting time increased slowly; When the dosage more than 0.1%, the initial setting time increased slowly, but the final setting time increases rapidly; With the increase in citric acid dosage, AFt diffraction peaks increases, while the CH peak decreases, indicating that the citric acid accelerated the initial hydration of C3A, while inhibiting C3S hydration and promoting AFt generation

Polymeric calcium phosphate cements incorporated with poly-γ-glutamic acid: Comparative study of poly-γ-glutamic acid and citric acid

2009 ◽  
Vol 113 (2) ◽  
pp. 1223-1231 ◽  
Author(s):  
Sung Soo Kim ◽  
Mijung Seo ◽  
Jin Wha Chung ◽  
Soon Yong Kwon ◽  
Yong-Sik Kim
Keyword(s):  
Citric Acid ◽  
Calcium Phosphate ◽  
Comparative Study ◽  
Glutamic Acid ◽  
Calcium Phosphate Cements

Development of Injectable Calcium Phosphate Cement Adding with ZrO2

2007 ◽  
Vol 361-363 ◽  
pp. 347-350
Author(s):  
J.Y. Gong ◽  
Shu Xin Qu ◽  
Q. Cui ◽  
Jie Weng
Keyword(s):  
Compressive Strength ◽  
Calcium Phosphate ◽  
Setting Time ◽  
X Ray Diffraction ◽  
Liquid Component ◽  
X Ray ◽  
Initial Setting Time ◽  
Mass Fractions ◽  
Initial Setting ◽  
Diffraction Peaks

In the present study, ZrO2 was added into the injectable calcium phosphate cements (CPCs) to improve their mechanical strength. Different mass fractions of ZrO2 (5 %, 10 %, 15 %, 20%) were mixed with the powder components consisted of tricalcium phosphate (α-TCP) and hydroxyapatite (HA). Then formed the paste via adding the liquid component consisted of citric acid. The compressive strength, the injectability, the initial setting time and finial time of CPC were measured, respectively. X-ray diffraction (XRD) was employed to analyse the phase of as-prepared CPC. Scanning Electron Microscope (SEM) and Energy dispersive spertrum (EDS) were used to observe the morphology and indicate the element components of CPC. The compressive strength of ZrO2-CPC was higher than that of CPC without added ZrO2. The compressive strength got the maximal when the mass fraction of ZrO2 was 15%. It had no effect on the injectability with adding ZrO2, which were 89 % to 92 %. It had a slight down-regulation of the initial and final setting time with adding ZrO2. SEM showed that there was amounts needle-like substance in CPC, which might be related to the improvement of compressive strength of CPC. XRD showed that there were HA, a few of α-TCP and ZrO2 diffraction peaks in CPCs. The present results indicate that it is feasible to improve the compressive strength of injectable CPC via adding ZrO2.

Modification of Retarder on Desulfurization Gypsum Wall Material

2013 ◽  
Vol 741 ◽  
pp. 45-48 ◽  
Author(s):  
Fu Sheng Niu ◽  
Ai Hong Guo ◽  
Xiang Wen Feng ◽  
Ying Meng
Keyword(s):  
Citric Acid ◽  
Sodium Citrate ◽  
Sodium Tripolyphosphate ◽  
Setting Time ◽  
Sodium Hexametaphosphate ◽  
Wall Material ◽  
Crystal Nucleus ◽  
Initial Setting Time ◽  
Final Setting Time ◽  
Initial Setting

In order to broaden the utilization of desulfurization gypsum in China and achieve the direct usage of desulfurization gypsum, in this paper, citric acid (CA), sodium citrate (SCA), sodium tripolyphosphate (STPP), Sodium hexametaphosphate (SP) were selected as retarder to modify desulfurization gypsum. The experiment results are as follows: the effect of SP, STPP, CA, SCA on desulfurization gypsum initial setting time is obvious; the turn is STPP> CA> SCA> SP; when the retarder dosage of STPP in desulfurization gypsum reaches 0.5%, the initial setting time can be extended to 210 min, the final setting time to 240min, which fully meets the demand of gypsum-site construction; inhibiting gypsum particles dissolution and preventing the growth of crystal nucleus are the fundamental reasons of STPP.

scholarly journals Effect of poly(ethylene glycol) on the injectability, setting behavior and mechanical properties of calcium phosphate bone cement

2018 ◽  
Vol 19 (2) ◽  
pp. 192-202
Author(s):  
Sufiamie Hablee ◽  
IIS SOPYAN ◽  
Maizirwan Mel ◽  
Hamzah Mohd. Salleh ◽  
Md. Mujibur Rahman
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Calcium Phosphate ◽  
Ethylene Glycol ◽  
Setting Time ◽  
Poly Ethylene Glycol ◽  
Initial Setting Time ◽  
Final Setting Time ◽  
Initial Setting ◽  
Poly Ethylene

ABSTRACT: The present paper reports on the effect of poly(ethylene glycol) (PEG) addition on injectability, setting behaviour, and mechanical properties of calcium phosphate cement (CPC) for injectable bone filling applications. Calcium hydroxide, Ca(OH)2, and diammonium hydrogen phosphate, (NH4)2HPO4, have been used as precursors in wet chemical precipitation synthesis of hydroxyapatite powder. Cement paste was prepared with different powder-to-liquid ratios, varied at 1.0, 1.3, 1.5 and 2.0. The incorporation of PEG was also varied at 1, 2, 3, 4 and 5 wt% at the powder-to-liquid ratio of 1.3. The CPC produced was then evaluated in terms of injectability, setting time and mechanical strength. The results indicated that PEG addition significantly improved setting time, injectability, as well as compressive strength of CPC. Without PEG, the initial setting time ranged between 3 and 122 min, while the final setting time ranged between 5 and 277 min. The addition of PEG has significantly improved setting time where the initial setting time ranged from 47 to 88 min and the final setting time ranged from 182 to 228 min. The extrusion load decreased when PEG was added, which revealed an improvement in injectability; 82.5% without PEG addition and 95.5% when 5% PEG was added. The compressive strength of CPC is in the range of 0.59 to 1.344 MPa and its porosity is in the range of 39.2% to 47.1%. With the incorporation of PEG, the compressive strength greatly increased to the range of 1.167 and 1.786 MPa.. ABSTRAK: Penyelidikan ini melaporkan tentang kesan menambah polietilina glikol (PEG) terhadap sifat-sifat simen kalsium fosfat seperti keupayaan suntikan, masa pengerasan dan kekuatan mekanikal. Kalsium hidroksida dan diammonium hidrogen fosfat digunakan sebagai reagen dalam kaedah pemendakan kimia basah bagi menghasilkan serbuk hidroksiapatit. Pes simen disediakan dengan nisbah serbuk kepada cecair yang berbeza, dengan nisbah 1.0, 1.3, 1.5 dan 2.0. Kemudian, PEG ditambah ke dalam simen kalsium fosfat dengan kepekatan yang berbeza, bernilai 1, 2, 3, 4 dan 5 wt% bagi 1.3 nisbah serbuk kepada cecair. Simen yang terhasil diuji bagi menilai keupayaan suntikan, masa pengerasan dan kekuatan mekanikal. Keputusan ujian-ujian tersebut menunjukkan bahawa penambahan PEG ke dalam simen telah meningkatkan kebolehan simen untuk disuntik, mengurangkan masa pengerasan simen dan meningkatkan kekuatan mekanikal simen. Simen tanpa PEG mempunyai masa pengerasan awal daripada 3 min kepada 122 min dan masa pengerasan akhir daripada 5 min kepada 277 min. Apabila PEG ditambah, masa pengerasan simen menjadi lebih baik dengan masa pengerasan awal daripada 47 min kepada 88 min dan masa pengerasan akhir daripada 182 min kepada 228 min. Peningkatan dalam keupayaan simen untuk disuntik telah dibuktikan dengan pengurangan beban penyempitan apabila PEG ditambah ke dalam simen. Simen tanpa PEG mempunyai 82.5% keupayaan suntikan dan meningkat kepada 95.5% apabila 5% PEG ditambah. Kekuatan mampatan simen bernilai antara 0.59 dan 1.334 MPa dan keliangan simen bernilai antara 39.2% dan 47.1%. Kekuatan mampatan simen meningkat dengan ketara apabila PEG ditambah, bernilai antara 1.167 dan 1.786 Mpa.

scholarly journals Effect of Calcium Nitrate on the Properties of Portland–Limestone Cement-Based Concrete Cured at Low Temperature

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1611
Author(s):  
Gintautas Skripkiūnas ◽  
Asta Kičaitė ◽  
Harald Justnes ◽  
Ina Pundienė
Keyword(s):  
Compressive Strength ◽  
Cement Paste ◽  
Setting Time ◽  
Calcium Nitrate ◽  
Curing Temperature ◽  
Hardened Concrete ◽  
Cement Pastes ◽  
Initial Setting Time ◽  
Initial Setting ◽  
Early Strength

The effect of calcium nitrate (CN) dosages from 0 to 3% (of cement mass) on the properties of fresh cement paste rheology and hardening processes and on the strength of hardened concrete with two types of limestone-blended composite cements (CEM II A-LL 42.5 R and 42.5 N) at different initial (two-day) curing temperatures (−10 °C to +20 °C) is presented. The rheology results showed that a CN dosage up to 1.5% works as a plasticizing admixture, while higher amounts demonstrate the effect of increasing viscosity. At higher CN content, the viscosity growth in normal early strength (N type) cement pastes is much slower than in high early strength (R type) cement pastes. For both cement-type pastes, shortening the initial and final setting times is more effective when using 3% at +5 °C and 0 °C. At these temperatures, the use of 3% CN reduces the initial setting time for high early strength paste by 7.4 and 5.4 times and for normal early strength cement paste by 3.5 and 3.4 times when compared to a CN-free cement paste. The most efficient use of CN is achieved at −5 °C for compressive strength enlargement; a 1% CN dosage ensures the compressive strength of samples at a −5 °C initial curing temperature, with high early strength cement exceeding 3.5 MPa but being less than the required 3.5 MPa in samples with normal early strength cement.

scholarly journals Non-Dispersive Anti-Washout Grout Design Based on Geotechnical Experimentation for Application in Subsidence-Prone Underwater Karstic Formations

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1587
Author(s):  
Khaqan Baluch ◽  
Sher Q Baluch ◽  
Hyung-Sik Yang ◽  
Jung-Gyu Kim ◽  
Jong-Gwan Kim ◽  
...  
Keyword(s):  
Fractured Rock ◽  
Setting Time ◽  
Visual Assessment ◽  
Initial Setting Time ◽  
Permeable Sediments ◽  
Coarse Aggregates ◽  
Saturated Rock ◽  
Initial Setting ◽  
Level 3 ◽  
Grey Relational

A new non-dispersive, anti-washout grout consisting of ordinary Portland cement, slag, superplasticizer, and methylbenzyl cellulose is proposed herein for the treatment of open karst, jointed and fractured rock, open-work gravel, and permeable sediments. A series of laboratory experiments were performed to design an anti-wash out grout suitable for grout injection of coarse aggregates depicting partially and open-jointed saturated rock mass and grouting concrete aggregates for underwater construction. The Taguchi orthogonal array was used to obtain nine different grout mix ratios. A total of four variables were considered, each with three different levels of the water–cement ratio, slag, and dosage of additives such as the superplasticizer and methyl benzyl cellulose. The laboratory determination of grout characteristics recording of mini slump, temperature, pH, visual assessment of grout dispersion, bleeding, and initial setting time and as well as uniaxial compressive strengths and permeabilities of the hardened grout samples were tested. To evaluate the suitability of the grout mixes, an analysis of variance was used for factor analysis and Grey relational analysis (GRA) was used to determine the optimal grout mix design. Based on the GRA, the following levels of the factors afforded the best results: water level 1 (0.3%), SP level 3 (0.01%), methylbenzyl cellulose level 2 (0.002%), and slag level 3 (0.1%). This paper describes the research methodology, detailed research observations, and analyses involved in designing the appropriate concrete mix. Based on the conclusions, relevant commendations regarding the suitability of grout testing equipment and grout mix designs are presented.

scholarly journals Nanostructured Strontium-Doped Calcium Phosphate Cements: A Multifactorial Design

2021 ◽  
Vol 11 (5) ◽  
pp. 2075
Author(s):  
Massimiliano Dapporto ◽  
Davide Gardini ◽  
Anna Tampieri ◽  
Simone Sprio
Keyword(s):  
Calcium Phosphate ◽  
Setting Time ◽  
Processing Parameters ◽  
High Energy ◽  
Powder Particle Size ◽  
Extrusion Force ◽  
Precise Control ◽  
Calcium Phosphate Cements ◽  
Shear Mixing ◽  
Mixing Techniques

Calcium phosphate cements (CPCs) have been extensively studied in last decades as nanostructured biomaterials for the regeneration of bone defects, both for dental and orthopedic applications. However, the precise control of their handling properties (setting time, viscosity, and injectability) still represents a remarkable challenge because a complicated adjustment of multiple correlated processing parameters is requested, including powder particle size and the chemical composition of solid and liquid components. This study proposes, for the first time, a multifactorial investigation about the effects of powder and liquid variation on the final performance of Sr-doped apatitic CPCs, based on the Design of Experiment approach. In addition, the effects of two mixing techniques, hand spatula (low-energy) and planetary shear mixing (high-energy), on viscosity and extrusion force were compared. This work aims to shed light on the various steps involved in the processing of CPCs, thus enabling a more precise and tailored design of the device, based on the clinical need.

scholarly journals Aplikasi Response Surface Methodology pada Optimasi Penambahan Blast Furnace Slag Terhadap Waktu Pengikatan dan Kuat Tekan Semen

2020 ◽  
Vol 4 (1) ◽  
pp. 61
Author(s):  
Hardjono Hardjono ◽  
Cucuk Evi Lusiani ◽  
Agung Ari Wibowo ◽  
Mochammad Agung Indra Iswara
Keyword(s):  
Compressive Strength ◽  
Response Surface Methodology ◽  
Blast Furnace ◽  
Response Surface ◽  
Blast Furnace Slag ◽  
Setting Time ◽  
Initial Setting Time ◽  
Initial Setting ◽  
Central Composite ◽  
Furnace Slag

Produksi semen setengah jadi (clinker) membutuhkan energi yang tinggi sehingga menggunakan batu bara dalam jumlah besar. Hal ini menyebabkan biaya produksi dari pabrik semen juga tinggi. Kebutuhan energi yang besar untuk menghasilkan clinker tersebut dapat dikurangi dengan menambahan blast furnace slag sebagai campuran pembuatan semen. Campuran clinker dapat menghasilkan produk semen yang memiliki waktu pengikatan dan kuat tekan sesuai SNI. Pengaruh penambahan blast furnace slag sebagai campuran clinker terhadap waktu pengikatan dan kuat tekan semen dapat dioptimalkan dengan response surface methodology (RSM) menggunakan Central Composite Design (CCD). Optimasi dengan menggunakan RSM bertujuan untuk mengetahui kondisi optimum pada penambahan blast furnace slag dan clinker terhadap variabel respon berupa waktu pengikatan awal, waktu pengikatan akhir, dan kuat tekan. Hasil uji ANOVA dan analisis response surface menunjukkan bahwa penambahan blast furnace slag sebagai campuran dalam pembuatan semen memberikan pengaruh yang signifikan terhadap waktu pengikatan awal, waktu pengikatan akhir, dan kuat tekan. Penambahan 5% blast furnace slag dengan 92,5% clinker pada campuran clinker dan gypsum merupakan kondisi optimum yang memberikan pengaruh signifikan terhadap variabel respon.The production of clinker consumes high energy and causes high production cost of cement industry. It can be reduced by adding blast furnace slag as a mixture in cement production. The blast furnace slag - clinker mixture can produce cement with setting time and compressive strength according to SNI. The effect of the addition of blast furnace slag as a clinker mixture to the setting time and compressive strength of cement can be optimized by response surface methodology (RSM) using Central Composite Design (CCD). Optimization by using RSM aims to determine the optimum condition of the blast furnace slag – clinker mixture to the initial setting time, final setting time, and compressive strength. ANOVA test results and response surface analysis show that the addition of blast furnace slag into the cement mixture has a significant influence on the initial setting time, final setting time, and compressive strength. The addition of  5% blast furnace slag with  92.5% clinker in the mixture of clinker and gypsum is the optimum condition which gives a significant effect on the response variable.

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