Cellulose Diacetate/Organoclay Nanocomposites as Controlled Release Matrices for Pest Control Applications

This study aimed to develop cellulose-based polymer matrices as controlled release devices for plant-based insect repellents and attractants, with the aim of finding sustainable and environmentally friendly pest control methods for agricultural applications. Citronellol, terpineol and methyl salicylate were the selected active compounds for this study. Their compatibility with cellulose diacetate was predicted using Hansen Solubility Parameters, which predicted terpineol as the most compatible with cellulose diacetate, followed by methyl salicylate and citronellol. This was consistent with the plasticization efficiency trend from DMA results of solvent cast cellulose diacetate films containing the active compounds. The chemical identity of the films and cellulose diacetate-active compound intermolecular interactions were verified by FTIR. TGA demonstrated the thermal stability of cellulose diacetate/active compound/clay formulations at temperatures not exceeding 170 °C. Cellulose diacetate/organoclay nanocomposite matrices containing the active compounds at 35 wt-% were prepared by twin screw extrusion compounding, with the active compounds also functioning as plasticizers. The amount of active compound in the strands was determined by solvent extraction and TGA. Both methods showed that small amounts of active compound were lost during the compounding process. SEM demonstrated the effect of organoclay on the internal morphology of the matrix, whereas TEM showed clay dispersion and intercalation within the matrix. The matrix served as a reservoir for the active compounds while simultaneously controlling their release into the environment. Release profiles, obtained through oven ageing at 40 °C for 70 days, were fitted to existing Log-logistic and Weibull models, and novel Diffusion and Modified Weibull release models. Citronellol was released the fastest, followed by methyl salicylate and terpineol. The findings suggest that cellulose diacetate/organoclay strands are promising controlled-release matrices for pest control purposes.

Reutilization of Recycled Cellulose Diacetate From Discarded Cigarette Filters in Production of Stone Mastic Asphalt Mixtures

In this paper, recycled cellulose diacetate (rCDA) derived from cigarette butts was used as a fiber stabilizer to develop stone mastic asphalt (SMA) mixtures. The characterizations of rCDA were investigated by scanning electron microcopy (SEM), a Fourier transform infrared spectrometer (FTIR), and a thermogravimetric analyzer (TGA). Volumetric stability, temperature stability, moisture stability, and fatigue performance of SMA mixtures with rCDA were tested to obtain the pavement performance. Results showed that rCDA appeared to have a tough surface texture with a curly and corrugated structure, which facilitated the enhancement of the cohesion bond with the asphalt binder. TG-DTG indicated that the maximum weight loss (62.48%) obtained at temperatures ranging from 294.1°C to 376.0°C was due to decomposition and degradation of organic matters. When 0.4% rCDA was used in the asphalt mixture, the dynamic stability was 4,105 cycles/mm. The ultimate flexural strength and flexural stiffness modulus were 3,722 MPa and 9.7 MPa. It indicated that the temperature stability of 0.4% rCDA was superior to 0.3% polyacrylonitrile fiber (PAN), while inferior to 0.3% polyester (PET). The value of tensile strength ratio and residual Marshall stability were 80.2 and 75.3%, respectively. The fatigue life of 0.4% rCDA was technically like that of 0.3% PAN and 0.3% PET at lower stress levels. All results concluded that the optimum content of rCDA in asphalt mixtures was 0.4% by mass of the binder.

Constructing Cellulose Diacetate Aerogels with Pearl-Necklace-Like Skeleton Networking Structure

Cellulose and its derivative aerogels have attracted much attention due to their renewable and biodegradable properties. However, the significant shrinkage in the supercritical drying process causes the relatively high thermal conductivity and low mechanical property of cellulose and its derivatives aerogels. Considering the pearl-necklace-like skeleton network of silica aerogels, which can improve thermal insulation property and mechanical property. Herein, we propose a new strategy for fabricating cellulose diacetate aerogels (CDAAs) with pearl-necklace-like skeletons by using tert-butanol (TBA) as exchange solvent after experiencing the freezing-drying course. CDAAs obtained have the low density of 0.09 g cm−3, the nanopore size in the range of 10–40 nm, the low thermal conductivity of 0.024 W m−1 K−1 at ambient conditions, and the excellent mechanical properties (0.18 MPa at 3% strain, 0.38 MPa at 5% strain). Ultimately, CDAAs with moderate mechanical property paralleled to cellulose-derived aerogels obtained from supercritical drying process are produced, only simultaneously owning the radial shrinkage of 6.2%. The facile method for fabricating CDAAs could provide a new reference for constructing cellulose/cellulose-derived aerogels and other biomass aerogels.

Sintesis dan Karakterisasi Selulosa Asetat dari A-Selulosa Fiber Cake Kelapa Sawit

Penelitian tentang sintesis dan karakterisasi selulosa asetat dari ?-selulosa fiber cake kelapa sawit ini telah dilakukan dengan menggunakan anhidrida asetat sebagai acetylating agent. Penelitian ini bertujuan untuk mendapatkan selulosa asetat dengan klasifikasi selulosa diasetat yang memiliki yield produk yang tinggi, mempelajari pengaruh variasi rasio selulosa:anhidrida asetat, waktu asetilasi, dan suhu asetilasi untuk mendapatkan selulosa asetat dengan kondisi yang optimal dari ?-selulosa fiber cake kelapa sawit. Penelitian ini menggunakan variasi rasio selulosa:anhidrida asetat (1:5; 1:10; 1:15), waktu asetilasi (0,5; 1; 1,5; 2; 2,5)jam, dan suhu asetilasi (25 dan 40) oC menghasilkan 30 sampel produk. Hasil penelitian menunjukkan bahwa selulosa asetat yang didapatkan berupa selulosa diasetat dengan bentuk padatan berupa serbuk, berwarna putih gading, dan tidak berbau serta memiliki kadar ?-selulosa sebesar 84,29 % dengan kadar air 9,16 % pada rasio selulosa:anhidrida asetat (1:10), waktu asetilasi 1,5 jam, dan suhu asetilasi 40oC dengan nilai yield produk, kadar asetil, dan derajat substitusi berturut-turut 49 %, 39,97 %, dan 2,5. Research on the synthesis and characterization of cellulose acetate from palm oil ?-cellulose fiber cake has been carried out using acetic anhydride as an acetylating agent. This study aims to obtain cellulose acetate with cellulose diacetate classification which has a high product yield, study the effect of variations in the ratio of cellulose:acetic anhydride, acetylation time, and acetylation temperature to obtain cellulose acetate with optimal conditions from palm oil ?-cellulose fiber cake. This study used variations in the ratio of cellulose:acetic anhydride (1:5; 1:10; 1:15), acetylation time (0.5; 1; 1.5; 2; 2.5) hours, and acetylation temperature (25 and 40) oC produces 30 product samples. The results showed that the cellulose acetate obtained was in the form of cellulose diacetate with a solid form in the form of powder, ivory white, and odorless and had 84.29% of a-cellulose content with 9.16% of a moisture content at the ratio of cellulose:acetic anhydride (1 :10), acetylation time 1.5 hours, and acetylation temperature 40oC with product yield, acetyl content, and degree of substitution 84.6%, 39.97%, and 2.5, respectively.

Novel Cellulose Triacetate (CTA)/Cellulose Diacetate (CDA) Blend Membranes Enhanced by Amine Functionalized ZIF-8 for CO2 Separation

Currently, cellulose acetate (CA) membranes dominate membrane-based CO2 separation for natural gas purification due to their economical and green nature. However, their lower CO2 permeability and ease of plasticization are the drawbacks. To overcome these weaknesses, we have developed high-performance mixed matrix membranes (MMMs) consisting of cellulose triacetate (CTA), cellulose diacetate (CDA), and amine functionalized zeolitic imidazolate frameworks (NH2-ZIF-8) for CO2 separation. The NH2-ZIF-8 was chosen as a filler because (1) its pore size is between the kinetic diameters of CO2 and CH4 and (2) the NH2 groups attached on the surface of NH2-ZIF-8 have good affinity with CO2 molecules. The incorporation of NH2-ZIF-8 in the CTA/CDA blend matrix improved both the gas separation performance and plasticization resistance. The optimized membrane containing 15 wt.% of NH2-ZIF-8 had a CO2 permeability of 11.33 Barrer at 35 °C under the trans-membrane pressure of 5 bar. This is 2-fold higher than the pristine membrane, while showing a superior CO2/CH4 selectivity of 33. In addition, the former had 106% higher CO2 plasticization resistance of up to about 21 bar and an impressive mixed gas CO2/CH4 selectivity of about 40. Therefore, the newly fabricated MMMs based on the CTA/CDA blend may have great potential for CO2 separation in the natural gas industry.