Manufacture of Mikania micrantha vinegar and investigation of its repellent activity for Forcipomyia taiwana

Crude vinegar was prepared from Mikania micrantha plants using a steel kiln. The ether-extracted vinegar and acidic, phenolic, and neutral fractions were obtained by the partition method. The fundamental properties of crude vinegar, including its fractions applied to repel biting midges (Forcipomyia taiwana), were investigated. Results indicated that the crude vinegar had a moisture content of 91%, Gardner color value of 11.2, a reddish-brown color, specific gravity of 1.0164, pH of 5.36, organic acid content of 2.50%, and soluble tar content of 0.78%. In ether-extracted vinegar of M. micrantha, the acidic component was the major ingredient, followed by the neutral, phenolic, and nitrogenous components. The main organic compounds of the acidic, phenolic, nitrogenous, and neutral components were acetic acid, phenol, 3-pyridinol, and 2-furanmethanol, respectively. The results also demonstrated that the crude vinegar, ether-extracted vinegar, and the phenolic and neutral fractions effectively repelled biting midges, with absolute repellent times of 49, 87, 83, and 99 min, respectively. The repellent activity of ether-extracted vinegar and the phenolic and neutral fractions of M. micrantha vinegar on biting midges was higher than that of a commercial repellent agent (named Dinling) with absolute repellent time of 61 min.

Cationic copolymerization of 1,3-pentadiene with α-pinene

The cationic copolymerization of 1,3-pentadiene (PD) with α-pinene (AP) initiated by aluminum trichloride (AlCl3) was carried out in N-pentane solvent. The effects of the polymerization temperature and the comonomer composition on the yield of the copolymer, softening point, Gardner color scale and number-average molecular weight (Mn) are discussed. The performance of the copolymer was better than that of AP homopolymer (PAP) and PD homopolymer (PPD). The structure of the copolymer was characterized by Fourier transform infrared spectroscopy (FT-IR), 1H-nuclear magnetic resonance (1H-NMR), 13C-NMR, differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). In addition, the reactivity ratios for AP (M1) and PD (M2) determined by the Kelen-Tudos method from low-conversion data are r1=0.58 and r2=5.92, respectively.

Preparation of Light-Color Rosin and Preliminary Analysis of Decoloration Mechanism

Color of rosin is an important evaluation quality index. A process for preparing light-color rosin by adding different chemical additives in the reaction was studied. The results showed that the best light-color rosin can be produced by adding TM430 and TM923. Mechanism of decoloration was studied by ultraviolet spectra. The Gardner color of rosin was reduced from 7 to 2 and the acid value and softening point changed a little where the TM430 dosage of 0.2% based on the weight of the starting rosin, in atmospheres of nitrogen for protection, reaction time for 2h. The decoloration mechanism was analyzed with UV.The hydrogen atom generated by disproportionate catalytic reaction with TM430. The color substances in the raw rosin were reduced to colorless by hydrogen atom generated by catalytic of TM430.

Study on Chromaticity Variation Relationships of Rosin under High Temperature Treatment

The color-lightening of rosin was achieved to give light-colored and qualified rosin that was improved at the optimal conditions for 4 Gardner color grades, while rosin was treated at 180 ~ 270 °C for 1 ~ 4 h in inert gases. The color of rosin was deepened slightly at the initial, and then gradual lightened with the increase of treating temperature. The best color-lightening effect was observed from Pinus massoniana rosin. The acid number and softening point of rosin tended to decrease both accompanying with the color-lightening. According to a general consideration on main requirements such as color, acid number, softening point and the others, the suitable treating conditions for rosin color-lightening were suggested to be as temperature 240 ~ 260 °C and time 1 ~ 3 h.

Study on Preparing Light Colored C9 Petroleum Resins with High Softening Point

Polymerizable C9 fraction was cut by atmospheric distillation of raw C9 fraction from thermal cracking. The obtained fraction polymerized using boron trifluoride ethyl ether as catalyst and then the polymerized mixture was washed by warm 10%wt Na2CO3 aqueous solution and distilled water and separated by vacuum distillation for producing light colored C9 petroleum resins with high softening point. The suitable conditions for polymerization process, washing process, vacuum distillation process were investigated to improve the C9 petroleum resins production. Under these conditions, the petroleum resins product with Gardner color index of 4-5 and softening point of 102-120°C could be obtained.