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Many crystalline polymers exhibit phase transitions between the low-and high-temperature phases during the heating process. Sometimes, however, the temperature-dependent measurement of the X-ray diffraction peaks and vibrational spectra leads us to the incorrect conclusion that these two phases transform in a direct solid-to-solid transition mode instead of the melt and recrystallization process. As a reliable method to confirm the transition behavior just below the melting region, we have developed a temperature-jump cell system, with which a time-dependent measurement of the X-ray diffraction peaks (and Fourier-transform infrared spectra) is performed in the rapidly changing temperature process from the low-to the hightemperature phase. This method was applied to two types of polymers and revealed that (i) the high-temperature phase transition of poly(vinylidene fluoride) is not a direct ferroelectric transition between the ferroelectric and paraelectric phases, as proposed in our previous studies (Polymer (1983), Polym. Bull. (1983)), but a melt of the ferroelectric phase (form I) followed by the recrystallization into the nonpolar crystalline phase (form III or V) and (ii) the b-to-a phase transition of trans-1,4-polyisoprene had been also controversial for many years but it was revealed to occur via a melt-recrystallization mechanism.

The newly developed system of simultaneous time-dependent measurements of wide-angle X-ray diffraction, small-angle X-ray scattering and transmission-type Fourier-transform infrared spectra has been applied to study the structural changes in the melt-and cold-crystallization processes of trans-1,4-polyisoprene (TPI). For the melt-isothermal crystallization process at 40 1C, the domains of relatively higher density with approximately 220 Å radius formed at first as the intermediate state, where the chain conformation was speculated to be considerably disordered. As time passed, the correlation length n between these domains decreased until they joined together to form the stacked lamellar structure. In these lamellae, the crystal lattices of the regular a form were created. When the isothermal crystallization was investigated at 30 1C, the intermediate-phase regularization caused the a-and b-crystalline forms to mix. In the cold-crystallization process or the heating process that started from the melt-quenched glass below À100 1C, TPI was found to crystallize at first to the b-form at approximately À55 1C, which transformed to the a-form at 50 1C via the amorphous phase as observed above. Keywords: crystallization; structure evolution; trans-1,4-polyisoprene INTRODUCTIONRecently, we developed a system of the simultaneous and timeresolved measurement of wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS) and transmission-type FTIR spectra during the application of external fields such as temperature and tensile stress. [1][2][3] This system can provide information about the structural evolution process of synthetic polymers viewed from various hierarchical levels. The infrared spectral data show the regularization of the molecular chain conformation. This spectroscopic data can be combined with the WAXD data to reveal the crystalline lattice formation with the ordered or disordered packing of these chains. The SAXS data, which show the creation process of stacked lamellae, must also be discussed in relation to this molecular-level information. In previous works, we reported several case studies including the tensile-force-induced phase transition of poly(tetramethylene terephthalate), 1 high-temperature phase transition of aliphatic nylons 2 and isothermal crystallizations of poly(L-lactic acid) 1 and polyethylene. 3 In this paper, we will treat the structural evolution processes in the crystallization phenomena of trans-1,4-polyisoprene (TPI), which is well known as Gutta Percha and is one of the typically used biodegradable green polymers in various fields to produce artificial

As a tropical country which has abundant of spices, Indonesia is challenged to increase the economic values of spices commodity in raw material form (wet or dry). One way to raise the economic values of these commodities is by modifying into its derivatives. Clove is one of spices commodity which can be processed furthermore into an essential oil. By transforming clove from raw material to essential oil, the economic value increases from 2 to 20 times per kilogram.  In this present research, the extraction time of clove oil using steam hydro distillation is reported. The distillation procedure was conducted in various times, that was in 3, 4, 5, and 6 hours. Furthermore, the clove oil sample that obtained from optimum extraction time was characterized using FTIR and GCMS. Then the result was compared to the commercial clove oil (100 % of purity). In support of sustainability process, then the clove buds waste from steam distillation were challenging to be one of eco-friendly packaging candidates. Two compositions of waste and additional material have been investigated in this study. It found that the best composition was composed of clove buds waste powder: recycled paper (7:3). During the casting process, some additives material was added such as tapioca (20%) and chitosan (1 %) in acid solution in order to improve its mechanical properties. Furthermore, thermal degradability of the eco-friendly packaging was studied. It was started to degrade at 286.58oC. According to this research, the cloves buds’ cardboard was quite potential to be developed as commercial eco-friendly packaging.

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