By means of calorimetric investigations it is shown that dithioVdiene-mixtures show a more or less distinct spontaneous dark reaction, without light and in the absence of initiators. Pyrogallol, hydroquinone and catechol were tested as stabilizers. The efficacy of the stabilizer to transform the radicals resulting from charge transfer interaction of the thiol with the ene component into an inactive species decreases in the order mentioned above. ZUSAMMENFASSUNG:DSC-Untersuchungen von DithioVDien-Mischungen zeigen, daB diese Systeme unter Lichtausschlun und in Abwesenheit von Sauerstoff eine mehr oder weniger deutlich ausgepragte Dunkelreaktion aufweisen. Als Stabilisatoren wurden Pyrogallol, Hydrochinon und Brenzkatechin getestet. Ihre Wirksamkeit, die aus der Charge-Transfer-Wechselwirkung des Thiols mit dem Dien resultierenden Radikale zu desaktivieren, sinkt in der genannten Reihenfolge.

The photoinitiated free-radical polymerization of 3,6-dioxa-1.8-octanedithiol and bis(ally1) hydroquinone ether or ethylene glycol divinyl ether leads to poly(thi0ethers) having antiMarkomikov structure with number-average molar mass M,,: 14000, 12000 g/mol, respectively. The chain propagation is limited by &sulfide production (nearly 3%) and cycle production (nearly 4%). Differential scanning calorimetry (DSC) investigations showed that the rate of polymerization decreases in the series vinyl ether ally1 ether > 1-alkenc The influence of the dithiol structure @hercapto ether, thioglycolate, aliphatic thiols) is not dominant.

DSC-und ESR-Messungen zur photosensibilisierten Polymerisation von 1,8-Dithio-3,6-dioxaoctan/Phthalsilurebisallylester zeigen, da8 die Reaktion in jedem Reaktionsschritt photoaktiviert erfolgt und da8 C-Radikale intermediilr auftreten. Modelluntersuchungen am System 1 -Octanthiol/Phenylallylether ergaben, da8 bevorzugt Photoaddition eintritt und d& Radikalrekombinationen von untergeordneter Bedeutung sind. Diese Befunde werden durch 'H-, I3C-NMR-und Massenspektren belegt. SUMMARY:DSC-and ESR-measurements during the photosensitized polymerization of 1,8-dithio-3,6-dioxaoctane with phthalic acid bisallyl ester showed that this reaction is photo-activated in each step and that C-radicals do occur. Model studies with the system octane thiol/phenyldlyl ether showed that photoaddition reaction happens and that radical recombinations are of minor signification.

The thermal properties of organic compounds intended to be applied as latent cold storage substances were investigated by methods of analysis according to Tammann, and by DTA and DSC. Findings were made concerning the melting and solidification behaviour, subcooling, specific melting enthalpies and specific heat capacities of paraffin mixtures, low and high-molecular glycols, ethylenediamine hydrates and formamide. Ethylenediamines and ethylene glycol, with high storage densities of 200-300 MJ.m -3, appear to be promising cold storage substances if subcooling is reduced. Through the use of congruently melting lowmolecular glycols and formamide, storage densities of about 170 MJ "m-are obtained. Paraffin mixtures and hi_g3h-molecular glycols melt in wide ranges of temperatures and give values of about I00 MJ -m-, which are not relevant to cold storage units.At present, energy storing systems based on melting and solidification or lattice transformation processes, also called latent storage units, have been developed for a temperature range of about 0-1500 ~ [1]. The application of latent cold storage units in the fields of room air conditioning, cooling and frost protection has been achieved for conditions below room temperature. Especially mixtures of salt and water, paraffins, glycols, amines and clathrates with high specific melting enthalpies, inexpensive ness and ready availability are considered as cold storing substances. Among these substances, attention has so far been paid only to the salt-water systems. The relevant data on the substances which are required for the development of storage systems are essentially known in the literature [2][3][4][5]. In contrast, there is only incomplete information on organic latent cold storage substances. There is some knowledge of the thermoanalytical behaviour of nalkanes and paraffin fractions [4,[6][7][8], caprylic, acrylic and acetic acids [6,[8][9][10], polyethylene glycols [9,11,12] and some substance combinations such as ethylenediamine with dimethyl sulphoxide [13].