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Incorrect levels of temperature and relative humidity hasten the deterioration of paper-based archives, irrespective of geographical location. An attempt to find a cheaper alternative to the costly installation of heating, ventilation, and air conditioning systems, the current research sought to test the capacity of different amounts of refrigerated margarine and zeolite respectively as alternative temperature and humidity control agents in archives in the Philippines, where varying amounts of sunlight and humidity during different times of the year become detrimental to maintaining an ideal storage condition. The resulting storage temperature and relative humidity where the test materials were introduced were compared against the temperature and relative humidity in storage where other commercially available phase change material (PCM) and desiccant were introduced, the room temperature and relative humidity, and the international standard temperature and relative humidity for archival storage. It had been found out that the optimum amount of refrigerated margarine that could perform well in the archive was 120 g as it resulted to an average temperature of 29.9475 °C, which was the closest any of the PCM samples used could get to achieve the standard archival temperature of 20 °C. On the other hand, the optimum amount for zeolite was 60 g. It resulted to an average of 57.825% relative humidity, which was 17.825% higher than the required relative humidity for archives. The best outcomes were observed when the two materials were introduced independently to the storage. Despite being able to deliver the desired results, refrigerated margarine and zeolite still require a few improvements before they become ready for their intended applications in archives. The small optimum amount of the refrigerated margarine and zeolite are beneficial in that it entails lower cost of materials. [ABSTRACT FROM AUTHOR]

The study of the behaviour of cellulose materials at low doses of ionizing radiation regained the interest because of the recent results showing that physical properties of the paper have less or no changes for absorbed doses below 10 kGy, despite the high decrease of the degree of polymerization. The understanding of the relationship among molecular, microscopic and macroscopic changes in cellulose materials may change the current opinion that irradiation of paper is not the best choice for conservation of cultural heritage. The aim of this study is to reveal the changes in gamma-irradiated pure cellulose paper by simultaneous TG/DSC analysis. For cellulose fibres, the thermal decomposition parameters depend on the cellulose degree of polymerization. For high irradiation doses, there is established a relationship between the absorbed dose and the degree of polymerization. However, a direct relationship between absorbed dose and the parameters of cellulose thermal decomposition for low irradiation doses was not established either in the literature or in our study. By using a peak separation technique, we studied the changes in the region of water loss (70-150 °C) and physical ageing (160-300 °C) for Whatman paper with low initial water content (<1 %), previously gamma irradiated at doses between 0 and 30 kGy. We concluded that strength of the hydrogen bond structure is increasing up to a point when the stress produces fractures in the fibrilar structure. This may explain the results reported for mechanical tests at low dose irradiation and it is in agreement with scanning electron microscopy pictures showing changes in fibril structure at high irradiation doses. Cellulose irradiated at low doses maintains its original hydrogen bond structure despite the decrease of the degree of polymerization. [ABSTRACT FROM AUTHOR]