Preparation of Urea Slow Release Membrane Environment Friendly

2012 ◽  
Vol 482-484 ◽  
pp. 1618-1621 ◽  
Author(s):  
Shu Jiang Wang ◽  
Xing Quan Wang ◽  
Ming Hui Chen
Keyword(s):  
Lactic Acid ◽  
Sustained Release ◽  
Corn Starch ◽  
Slow Release ◽  
Urea Formaldehyde ◽  
Raw Material ◽  
Poly Lactic Acid ◽  
Dialdehyde Starch ◽  
Membrane Absorption ◽  
High Efficient

First, the corn starch was taken as raw material, and then it was broken down by enzymes and fermentation by lactic acid bacteria, and the poly lactic acid was obtained by chemical synthesis. Then the corn starch was taken as raw material again, the dialdehyde starch was obtained by high efficient light-catalytic reactor. Secondly, a certain percentage of dialdehyde starch and urea were mixed together to get urea-formaldehyde resin. Finally, a certain amount of polylactic acid, urea formaldehyde resins and dispersions were put together and mixed in a high-speed stirring to get urea slow release membrane materials. Experimental results showed that it needed 150-300 days degradate completely by 75% poly lactic acid sustained release membrane, while 85% needed 100 -120 days. Single thin membrane absorption test showed that per unit area of the sustained release membrane absorption ability would increase with the poly lactic acid increased, and the absorbent capacity of 85% poly lactic acid of sustained release membrane was 112 times higher than the mass of itself.

scholarly journals Sustained Release of Hydrogen Sulfide (H2S) from Poly(Lactic Acid) Functionalized 4-Hydroxythiobenzamide Microparticles to Protect Against Oxidative Damage

2019 ◽  
Vol 47 (8) ◽  
pp. 1691-1700 ◽  
Author(s):  
Anh-Vu Do ◽  
Rasheid Smith ◽  
Phillip Tobias ◽  
Daniel Carlsen ◽  
Erica Pham ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Lactic Acid ◽  
Oxidative Damage ◽  
Sustained Release ◽  
Poly Lactic Acid

Toxicity Evaluation of Graphene and Poly(Lactic-Acid) Using a Nematode Model

2019 ◽  
Vol 290 ◽  
pp. 101-106
Author(s):  
Cin Kong ◽  
Azzahraa Izzati Aziz ◽  
Akesh Babu Kakarla ◽  
Ing Kong ◽  
Wei Kong
Keyword(s):  
Lactic Acid ◽  
Corn Starch ◽  
Feeding Activity ◽  
Reproductive Rate ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Live Animal ◽  
Pumping Rate ◽  
C Elegans ◽  
Significant Difference

Graphene has gained tremendous attention due to its unlimited potential in various applications while poly(lactic acid) (PLA) is a biodegradable thermoplastic polyester produced from fermenting corn starch. The incorporation of graphene into PLA has been proven to exhibit excellent mechanical and thermal properties. However, there are not many reports on the potential toxic effect of these materials towards living organisms. In this study, we investigated the possible toxicity of graphene and PLA-graphene in a live animal model, the nematode Caenorhabdits elegans (C. elegans). Alive adult worms were exposed directly to graphene and PLA-graphene across a range of concentrations from 50 µg/mL to 1000 µg/mL. After certain hours of exposure, the pharyngeal pumping rate (indicative of the C. elegans feeding activity), reproductive rate and lifespan of the worms were determined and compared to the untreated worm population. At all concentrations tested, both graphene and PLA-graphene do not affect the feeding rate of the nematode. Additionally, there was no significant difference between the lifespan of worms exposed to graphene and PLA-graphene as compared to the untreated control population (p>0.05). We examined the effect of graphene on nematode’s ability to reproduce and no reduction in progenies was detected (p>0.05). Taken together, our findings suggest that graphene and PLA-graphene do not possess a negative effect on the feeding activity, reproduction and overall lifespan of the host, indicating that these materials are safe to living organism at concentration up to 1000 µg/mL.

Preparation and performance evaluation of biodegradable corn starch film using poly (lactic acid) as waterproof coating

2019 ◽  
Vol 36 (6) ◽  
pp. 665-670
Author(s):  
Qinglu Chang ◽  
Yanling Hao ◽  
Long Cheng ◽  
Yihao Liu ◽  
Aoyun Qu
Keyword(s):  
Performance Evaluation ◽  
Lactic Acid ◽  
Corn Starch ◽  
Poly Lactic Acid ◽  
And Performance

Crystallization and Thermal Degradation of Green Nanocomposites Based on Lignin Coated Cellulose Nanocrystals and Poly(Lactic Acid)

2017 ◽  
Vol 737 ◽  
pp. 256-261 ◽  
Author(s):  
Martin Boruvka ◽  
Luboš Bĕhálek
Keyword(s):  
Lactic Acid ◽  
Cellulose Nanocrystals ◽  
Raw Material ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
Crystalline Cellulose ◽  
Melt Crystallization ◽  
Scanning Calorimetry ◽  
Wide Range ◽  
Twin Screw

Cellulose is almost inexhaustible source of raw material comprising at least one-third of all biomass matter. Through deconstruction of cellulose hierarchical structure can be extracted highly crystalline cellulose nanocrystals (CNC) with impressive properties. However, the main barrier in the processing of the nanocomposites based on CNC is their inhomogeneous dispersion and distribution in the non-polar polymer matrix. In this paper is this problem addressed by use of novel hydrophobic lignin coated CNC as a biobased nucleation agents in poly (lactic acid) (PLA) nanocomposites. These green nanocomposites based on natural plant derived substances have enormous potential to replace materials originated from non-renewable resources and show promise of providing degradation back into the environment when they are no longer needed. Resulted composites prepared by twin screw extrusion and injection moulding were characterized by means of scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The addition of L-CNC (1, 2 and 3 wt. %) into PLA increased melt crystallization enthalpy and decreases the cold crystallization enthalpy. The degree of crystallinity (cc) increased from 5.6 % (virgin PLA) to 8.5 % (PLA/1-L-CNC), 10.3 % (PLA/2-L-CNC) and 10.7 % (PLA/3-L-CNC). The wide range of degradation temperatures of lignin coating has been observed starting at 100 °C.

scholarly journals Production of D-Lactic Acid by the Fermentation of Orange Peel Waste Hydrolysate by Lactic Acid Bacteria

Fermentation ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 1 ◽  
Author(s):  
Daniel Bustamante ◽  
Marta Tortajada ◽  
Daniel Ramón ◽  
Antonia Rojas
Keyword(s):  
Lactic Acid ◽  
Reference Strain ◽  
Orange Peel ◽  
Ash Content ◽  
Lactobacillus Delbrueckii ◽  
Raw Material ◽  
Poly Lactic Acid ◽  
Biochemical Processes ◽  
Orange Peel Waste ◽  
Renewable Raw Material

Lactic acid is one the most interesting monomer candidates to replace some petroleum- based monomers. The application of conventional poly-lactic acid (PLA) is limited due to insufficient thermal properties. This limitation can be overcome by blending poly-D and poly-L-lactic acid. The main problem is the limited knowledge of D-lactic acid (D-LA) production. Efficient biochemical processes are being developed in order to synthesize D-LA from orange peel waste (OPW). OPW is an interesting renewable raw material for biorefinery processes of biocatalytic, catalytic or thermal nature owing to its low lignin and ash content. Bioprocessing of the pretreated OPW is carried out by enzymatic hydrolysis and fermentation of the released sugars to produce D-LA. Several strains of the species Lactobacillus delbrueckii ssp. bulgaricus have been evaluated for the production of D-LA from OPW hydrolysate using Lactobacillus delbrueckii ssp. delbrueckii CECT 286 as a reference strain since its performance in this kind of substrate have been widely reported in previous studies. Preliminary results show that Lactobacillus delbrueckii ssp. bulgaricus CECT 5037 had the best performance with a yield of 84% w/w for D-LA production and up to 95% (e.e.).

Lewis Acidic Ionic Liquid [Bmim]FeCl4 as a High Efficient Catalyst for Methanolysis of Poly (lactic acid)

2017 ◽  
Vol 147 (9) ◽  
pp. 2298-2305 ◽  
Author(s):  
Huiqing Liu ◽  
Ruiyang Zhao ◽  
Xiuyan Song ◽  
Fusheng Liu ◽  
Shitao Yu ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Lactic Acid ◽  
Poly Lactic Acid ◽  
Efficient Catalyst ◽  
Acidic Ionic Liquid ◽  
High Efficient ◽  
Lewis Acidic Ionic Liquid

Adsorption and Sustained Release of Insulin from Zinc Hydroxyapatite Microparticle with Poly (Lactic Acid) Coating

2008 ◽  
Vol 396-398 ◽  
pp. 507-510 ◽  
Author(s):  
Toru Tonegawa ◽  
Toshiyuki Ikoma ◽  
Tomohiko Yoshioka ◽  
Kazuo Shinozaki ◽  
Nobutaka Hanagata ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Adsorption Isotherm ◽  
Sustained Release ◽  
Outer Layer ◽  
Poly Lactic Acid ◽  
Initial Release ◽  
Apparent Reduction ◽  
Low Crystalline ◽  
Acid Coating

Insulin delivery carriers using low crystalline porous zinc hydroxyapatite (ZnHAp) microparticles with different crystal sizes and novel formulation method of poly (lactic acid) (PLA) have been developed to achieve the sustained-release of insulin. The adsorption isotherm curves of insulin dissolved into acetic acid of pH4.5 onto ZnHAp nanocrystals show non-Langmuir type due to the dissolution of the ZnHAp microparticles; the adsorption amounts were increased with the increase of crystalline sizes. The PLA formulation, coating the outer layer of microparticles, showed the apparent reduction of initial burst for insulin. The amounts of initial release of insulin decreased with the increase of crystalline sizes of ZnHAp, which could be attributed to the different meso-porous structure depending on its crystal sizes.

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