Prepared for the United States Energy Research and Development Administration under Contract no. E(40-18) 2295, Task order 6

This is an exploratory study. Its purpose is to delineate and identify the important factors influencing land use in Malaya during the period 1947 to I960. Since the subject of land use is very wide our aim is to deal only with agricultural land use. Other uses are discussed only incidentally or as they are involved in the shifting uses of land. The scope and nature of land use patterns in Malaya as in other countries, is a reflection of economic, geographical and political factors. Land use usually reflects the operation of the principle of comparative advantage. Theoretically different types of land would normally be put to their best uses and any instability which exists would be cleared up by the market mechanism. Institutional barriers often impede this development as we show in the Malayan case. Two conflicts are apparent in the land use policies in Malaya. The first is between rubber and rice; that is, whether to specialise in the production of rubber, over which Malaya has a comparative advantage, or to produce rice for subsistence over which Malaya does not have a comparative advantage. Of course the rational course from an economic point of view is to produce more rubber. But more than economics are involved in such issues. The other conflict is whether to produce rubber on estates, which are the large scale enterprises, or on smallholdings, which are the peasant, small scale enterprises. Again more than economics, are involved. In this study attention is focussed primarily on the rubber-rice land use pattern. Even then rubber gets most of the attention. Technical questions especially those relating to rubber are of considerable interest but these are discussed only insofar as they have general economic relevance. The study as a whole can be divided into three parts. Chapters I and II comprise the first section. The opening chapter contains the economic and historical background to the land use patterns in Malaya and points out the rubber-rice land use pattern. In Chapter II we discuss the theoretical, suggested effects of the dual pattern of land utilisation. An attempt is also made to apply the dualistic theories of economic growth to Malaya in order to ascertain whether the conclusions of these theorists are verified in Malaya. The second section comprises of Chapter III. Here we discuss the obstacles to good land utilisation in the post war period. The third major section takes up the remaining chapters, all of which deal largely with rubber, which is one of the mainstays of the Malayan economy. In Chapter IV we discuss the relative efficiency of estates and smallholdings as producers of rubber. This chapter may be said to contain the heart of the matter since it helps us to evaluate two recent developments, which are discussed in Chapters V and VI. Chapter V, the "break-up" of rubber estates, discusses the various aspects of estates which have been diminishing in size. The most important effect of this is the creation of smallholdings and a loss in government revenue. The second recent development, the land development schemes initiated by the government, is discussed in Chapter VI. Here again the chief effect is the creation of rubber smallholdings. The concluding chapter has the twofold aim of summarising the main findings to this study and of setting out briefly the possible future trends of land use in Malaya. / Arts, Faculty of / Vancouver School of Economics / Graduate

Improvements to the properties of recycled rubber, by developing a more selective breakdown process, is an important issue and a global challenge. Devulcanization is the most promising way to achieve this. It is a process which aims to totally or partially cleave monosulfidic (C-S-C), disulfidic (C-S-S-C) and polysulfidic (C-Sx-C) crosslinks of vulcanized rubber. In this study, the devulcanization of sulfur-vulcanized natural rubber with a variety of diphenyldisulfides has been studied using 2,3-dimethyl-2-butene and squalene as model compounds, vulcanized by sulfur and 2-bisbenzothiazole-2,2’-disulfide. 2-aminodiphenyldisulfide; 4-amino-diphenyldisulfide; bis(2-benzamido-)diphenyldisulfide and 2,2’-bithiosalicylic acid were used as aromatic disulfides devulcanization agents. Thermal analysis was used to investigate interactions between various combinations of curatives in the vulcanization systems in the absence of model compounds. Thermogravimetric analysis was used to detect mass changes during vulcanization and whether the samples decompose/evaporate so as not to contaminate differential scanning calorimetry instrumentation. Differential scanning calorimetry was used to investigate reactions occurring between curatives. Comparison of reversing and non-reversing signals in modulated experiments are suggestive of reactions between devulcanization agents and sulfur, and accelerators Vulcanization of the model compounds were performed in 10m evacuated sealed glass ampoules placed in an oil bath at 160 °C and agitated for the duration of vulcanization. After 60 min the ampoules were removed and quenched. These were then devulcanized by exposure to a devulcanization agent in a sealed ampoule at 180 for 60 min. Crosslinked 2,3-dimethyl-2-butene species were isolated and analysed by reversed phase high performance liquid chromatography. Particular attention was paid to changes in the number of sulfur atoms in the crosslinks. Results indicate that of the devulcanization agents tested 4-amino-diphenyldisulfide was the most effective. No detrimental effect on devulcanization efficiency was caused by the substitution of a basic amino group with an acidic carboxylic acid group Gel permeation chromatography was performed on devulcanized squalene crosslinks using a tetrahydrofuran eluent. GPC investigations with squalene were less effective than HPLC experiments with 2,3-dimethyl-2-butene at evaluating the relative efficiency of individual devulcanization agents. Results were, however, consistent with 4-amino-diphenyldisulfide again being the most efficient devulcanization agent.

Conservators have long been aware of the problems associated with the preservation of rubber objects due to inherent instability that can be attributed, in part, to the presence of additives. Inorganic additives, such as fillers, accelerators, stabilizers, and special ingredients are necessary in manufacturing to alter the properties of natural rubber. These materials all have different interactions with the rubber, and each other, and differing effects on the ageing process. To date, the most effective and accepted methods to preserve rubber are cold, dark storage of objects, or the use of low oxygen environments. While these methods are effective, they greatly limit access. The application of coatings to the surface of rubber objects can slow deterioration and greatly increase the ability of an institution to handle and display rubber objects. While numerous coatings for preventive and interventive treatment have been tested, none have been so successful to warrant routine use. The first section of this research highlighted the relationship between the inclusion of certain additives in natural rubber objects and the accelerated or slowed down overall degradation. In the second part of this research, the acrylic varnishes Golden Polymer Varnish with UVLS, Lascaux Acrylic Transparent Varnish-UV, Sennelier Matte Lacquer with UV Protection, and Liquitex Soluvar Varnish containing ultraviolet light absorbers or stabilizers were tested as a preventative coating for rubber. Through testing the visual and physical properties of the samples, as well as compound analysis the results of this research suggest that acrylic varnishes do provide protection, each to varying degrees. The results also provided insight into the behavior of rubber and these varnishes with continuing light exposure. / Thesis (Master, Art Conservation) -- Queen's University, 2013-10-04 20:14:54.597